American Wood CouncilDETAILS FORCONVENTIONAL WOODFRAME CONSTRUCTIONAmericanForest &PaperAssociationBy downloading any file to your computer, you are accepting and agreeing to the terms of ourend-user licensing agreement (EULA), which you may view here: End User License Agreement.Copyright infringement is a violation of federal law subject to criminal and civil penalties.Copyright 2001American Forest & Paper AssociationAMERICAN FOREST & PAPER ASSOCIATION1 WOOD CONSTRUCTION DATA 1Introduction ............................................. 3General Scope......................................... 3Grade Marking ........................................ 3Lumber Seasoning ................................. 4TYPES OF FRAME CONSTRUCTIONPlatform Frame ....................................... 4Balloon Frame ......................................... 5Fastenings ............................................... 5Plank and Beam Construction ............ 5Truss-Framed Construction ................. 5Foundations ............................................. 5Protection Against Termites andDecay .................................................. 6Floor Framing.......................................... 7Firestopping ............................................ 8Draftstopping.......................................... 8Exterior Wall Framing........................... 8Interior Partition Framing.................... 9Framing Around Chimneys andFireplaces .......................................... 9Roof and Ceiling Framing................. 10Insulation and Vapor Retarders....... 11Exterior Siding and Coverings ........ 11Flooring ................................................. 12Wood Decks ......................................... 13Conclusion ............................................ 14Appendix ................................................. 52TABLE OF CONTENTSLIST OF TABLESChapter/Title Page Chapter/Title PageI. Nominal and Minimum-Dressed Sizes ofBoards, Dimension and Timbers.............. 15II. Wood Shingle and Shake WeatherExposures .................................................16Table PageCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL2 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONLIST OF ILLUSTRATIONSFigure Page Figure Page1. Platform Frame Construction ...................... 172. Balloon Frame Construction ....................... 183. Methods of Loading Nails ............................ 184. Sizes of Common Wire Nails ....................... 195. Masonry Foundation Wall and Footing ...... 206a. Permanent Wood Foundation - Crawlspace .............................................................. 206b. Permanent Wood Foundation -Basement ....................................................... 217a. Sump for Poorly Drained Soils.................... 227b. Sump for Medium to Well Drained Soils .... 228. Pier Foundation and Anchorage ................. 239. Clearance Between Earth and FloorFraming .......................................................... 2310. Support for Basement Post ......................... 2311. Floor Framing at Exterior Wall .................... 2412. Girder Framing in Exterior Wall ................... 2413. Termite Shields.............................................. 2414. Anchorage of Sill to Foundation Wall ......... 2515. Nailing Built-up Beams and Girders ........... 2516. Joist End Bearing ......................................... 2517. Joist Supported on Ledger .......................... 2618. Joist Supported by Metal FramingAnchors.......................................................... 2619. Joists Resting on Girder .............................. 2620. Joists Resting on Steel Beam ..................... 2621. Diagonal Bridging of Floor Joists ............... 2722. Solid Bridging of Floor Joists ..................... 2723. Framing of Tail Joists on Ledger Strip ....... 2824. Framing of Tail Joists by FramingAnchors.......................................................... 2825. Framing of Header to Trimmer by JoistHangers.......................................................... 2826. Notching and Boring of Joists .................... 2827. Framing Over Bearing Partition,PlatformConstruction .................................. 2928. Framing Over Bearing Partition, BalloonConstruction.................................................. 2929. Framing Under Non-Bearing Partition........ 3030. Attachment of Non-Bearing Partition toCeiling Framing............................................. 3031. Interior Stairway Framing ............................ 3132. Stairway With a Landing .............................. 3233. Framing Supporting Bathtub....................... 3234. Second Floor Framing, Exterior Wall ......... 3335. Second Floor Overhang of Exterior Wall,Joists at Right Angles to SupportingWalls ............................................................... 3336. Second Floor Overhang of Exterior Wall,Joists Parallel to Supporting Walls............. 3337. Firestopping Around Pipes.......................... 3438. Firestopping of Dropped Ceilings............... 3439a. Firestoppingof Masonry Walls - Floor ........ 3539b.Firestopping of Masonry Walls - Ceiling .... 3540. Draftstopping of Trussed Floors................. 3641. Multiple Studs at Corners ............................ 3642. Wall Framing at Intersecting Partitions ...... 3643. Exterior Wall Openings, Header Detailswith Cripple Studs ........................................ 3744. Exterior Wall Openings, Header Detailswith Joist Hangers ........................................ 3745. Framing of Bay Window............................... 3846. Wall Framing at Gable Ends ........................ 3847a. Wall and Floor Framing at Fireplace........... 3947b. Hearth Centering Detail ................................ 3948a. Clearance of Fireplace Trim......................... 4048b. Section Through Mantle............................... 4049. Building Paper and Siding Application ...... 4150. Application of Wood Shingles ..................... 4151. Roof Framing Ceiling Joists Parallel toRafters ............................................................ 4252. Roof Framing, Ceiling JoistsPerpendicular to Rafters .............................. 4253. Roof Framing Gable Overhang.................... 4354. Flat Roof Framing ......................................... 4355. Valley Rafter Roof Framing.......................... 4456. Hip Rafter Roof Framing .............................. 4457. Roof Framing at Eave ................................... 4458. Shed Dormer Roof Framing......................... 4559. Gable Dormer Framing ................................. 4660. Roof Framing Around Chimney .................. 4661. Roof Ventilation Requirements ................... 4762. Ventilating Eave Overhangs ........................ 4763. Wood Siding Patterns and Nailing.............. 4864. Corner Treatments for Wood Siding........... 4865. Application of Masonry Veneer to WoodFraming .......................................................... 4966. Wood Strip Flooring ..................................... 4967. Wood Deck..................................................... 5068. Ceiling-Floor Partition Separation .............. 51Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION3 WOOD CONSTRUCTION DATA 1DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONThe first approach to achieving a strong, durable struc-ture, involving economical use of materials, is to follow abasic modular plan for layout and attachment of framingmembers.Suchmethodsusea4-footdesignmodule,which governs a 16-inch spacing of joists, studs, raftersand panel sheathing products. This module also providesfor alternate 24-inch spacing of floor, wall and roof fram-ingwherefloorandrooftrussesareused,andaccommodates 24-inch spacing of studs where wind loadspermit, or where larger studs are required for thicker in-sulation or heavier floor and roof loads.TerminologyPrevious versions of this document have followed thepractice of using shall and should to emphasize thosemandatoryinstructionscoveringfireandlifesafetyasseparate from general good practices cover durability, re-ducedmaintenancecostsandbestperformanceofproducts. Recognizing that the term should, in practice,canbeconsideredasoptionalandthatfailuretofollowsuch provisions can result in serious damage or excessivemaintenancecoststothehomeowner,thispublicationstates the procedure as it is to be illustrated in the houseplan, followed by the job foreman and subcontractors, andenforced by the building inspector.Whereverpossible,theprovisionsdescribedarein-tended to conform to current code provisions; however, itis recommended that the local building code be checkedforadditionalrequirements.Othermethodsofbuildingmayprovideequal,orpossibly,improvedperformance.These, however, must provide performance assurance ac-ceptable to the owner and the building inspector.DimensioningIn general, dimensions for framing lumber, wood sid-ingandtrimreferencedinthisdocumentarenominaldimensions; i.e., 2x4, 2x6, etc., for simplicity. Actual sur-faced dimensions conform with those in Product StandardPS 20, published by the American Lumber Standards Com-mittee(Appendix,Item2).Asummaryofthesedimensions is set forth in Table I.GRADE MARKINGFraming lumber, also referred to as dimension lum-ber, must be properly grade marked to be acceptable underthe major building codes. Such grade marks identify thegrade,speciesorspeciesgroup,seasoningconditionatINTRODUCTIONWood frame construction is the predominant methodofbuildinghomesandapartmentsintheUnitedStates,enabling this nation to have the worlds best housed popu-lation.Increasingly, wood framing is also being used in com-mercial and industrial buildings. Wood frame buildings areeconomical to build, heat and cool, and provide maximumcomfort to occupants. Wood construction is readily adapt-abletotraditional,contemporaryandthemostfuturisticbuilding styles. Its architectural possibilities are limitless.Historyhasdemonstratedtheinherentstrengthanddurability of wood frame buildings.The purpose of thisdocument is to summarize and illustrate conventional con-struction rules as a guide for builders, carpentry foremen,buildinginspectorsandstudentsinthebuildingtrades.Theapplicationofconventionalconstructionrulesmaybelimitedbybuildingcoderequirementsinusewherethe building is being constructed. Conventional construc-tionprovisions,asfoundinthispublication,representtechniques with a history of satisfactory performance.Today, some building codes may require a more rigor-ousstructuraldesignmethodologythanisassociatedwithconventional construction. This requirement may result froma need for better building performance when the structure isexposed to moderate-to-high wind, seismic, and snow loads.AF&PApublishestheWoodFrameConstructionManualfor One- and Two-Family Dwellings (Appendix, Item 1) toprovidesolutionsbasedonengineeringanalysis,inaccor-dancewithrecognizednationalcodesandstandards.Likeconventional construction, the engineered solutions are pro-vided in a prescriptive format.GENERAL SCOPEWith any building material or product, sound construc-tion and installation practices must be followed to assuredurabilityandtrouble-freeperformance.Areasforeconomy in basic design and house construction are cov-eredinnumerouspublications.However,skimpingonmaterials or using poor building practices in constructingthehouseframesaveslittle.Suchpracticesmayreducethe strength and rigidity of the structure and cause diffi-cultyinattachmentofcladdingmaterialsandtrim.Therefore, the details in this document are not intended tobe bare minimums; rather, they reflect requirements forproducing sound, low maintenance wood frame buildings.Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL4 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONtime of manufacture, producing mill number and the grad-ing rules writing agency.The bending strength, Fb, and the stiffness or modulusof elasticity, E, may be determined from the grade mark forlumberusedasjoists,rafters,anddecking. Thesevaluesenable determination of allowable spans for the lumber.Grading rules for various softwood and certain hard-woodspeciesarewrittenbyregionalruleswritingagencies, which operate within the system, established bythe American Lumber Standards Committee (ALSC) un-der the authority of the U.S. Department of Commerce.This system provides for on-going inspection of lumberproduced to the applicable rules and for monitoring of theinspection agencies by the Board of Review of the ALSC.Engineering values and tables of allowable spans forframinglumberareavailablefromthe AmericanForest& Paper Association (Appendix, Items 3 and 4), and theregional rules writing agencies.LUMBER SEASONINGWood loses moisture from the time it is cut and manu-factured into lumber until it reaches equilibrium in service.Best performance of wood frame buildings is obtained whenthe moisture content of framing lumber at the time the build-ing is enclosed with sheathing and interior finish, is as closeas possible to the condition it will reach in service.Gradingruleswhichconformwith AmericanSoft-wood Lumber Standard, PS 20, provide for framing lumbersurfaced to standard sizes at the unseasoned condition (S-Grn),at19percentmaximummoisturecontent(S-Dry)andat15percentmaximummoisturecontent(KD)or(MC-15). Standard sizes apply to S-Dry (19% max), withslightly larger sizes provided for S-Grn so that both prod-ucts reach approximately the same size after seasoning inservice. MC-15 lumber is produced to the same standardsize as S-Dry. In some cases engineering stress values as-signedtolumberproducedtodifferentseasoningconditions are adjusted to reflect the effects of seasoning.Lumber should be protected from weather at the jobsite. Buildings should be roofed and enclosed with sheath-ing without delay to maintain the original dryness of thelumber or to help unseasoned lumber reach equilibriumduring construction.Final moisture content of lumber in the building varieswith the geographic region and with location in the struc-ture.Floorjoistsoveracrawlspacemayreachseasonalmoisture contents in excess of 14 percent. Roof trusses andrafters, on the other hand, may dry below 6 percent. Squeak-ingfloorsandloosenailsinwallboardorsidingcanbereduced by allowing framing to season to a moisture con-tent which is as close as possible to moisture levels it willreach in service and by utilizing modern framing techniquesand products, including glued-nailed floor systems, groovedor ring-shanked nails, and drywall screws.Protection of MaterialsLumber, panel products and millwork (windows, doorsand trim) should be protected from the weather when de-livered at the building site. Preparation of a constructionschedule will assure that lumber and millwork are deliv-ered as needed. Follow these simple rules:(1) Support framing lumber, plywood and panel prod-uctsatleastsixinchesabovegroundandprotectthem below and above with a waterproof cover suchas plastic film. Finish lumber and flooring, particu-larly, are to be protected from ground or concreteslab moisture and kept under cover preferably in-doors until installation.(2) Store door and window assemblies, siding and ex-terior trim inside. Where this is not practical, thesematerialsaretobeelevatedfromthegroundandprotectedaboveandbelowwithaweatherproofcover.Millwork items are often pre-treated with a water-repellent preservative as received. Whether treatedor not, such materials are to be stored under cover.Untreatedexteriormillworkshouldreceiveawa-ter-repellentpreservativetreatmentbeforeinstallation.(3) Store interior doors, trim, flooring and cabinetworkin the building. Where wet plaster is used it must bepermitted to dry before interior woodwork, cabinetryand flooring are installed.TYPES OF FRAME CONSTRUCTIONPLATFORM FRAMEInplatform-frameconstruction,firstfloorjoistsarecompletely covered with sub-flooring to form a platformuponwhichexteriorwallsandinteriorpartitionsareerected.Thisisthetypeofconstructionmostgenerallyused in home building, Figure 1.Platformconstructioniseasytoerect.Itprovidesawork surface at each floor level and is readily adapted tovarious methods of prefabrication. In platform systems itCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION5 WOOD CONSTRUCTION DATA 1exterior sidings. Details for this method of framing are pro-vided in Plank and Beam Framing for Residential Buildings- Wood Construction Data No. 4, published by the Ameri-can Forest & Paper Association (Appendix, Item 5).TRUSS-FRAMED CONSTRUCTIONThestrengthandresilienceofwoodconstructionisdue to its framework of structural lumber combined witha covering of subflooring, wall and roof sheathing. Addi-tional engineering of the system through use of floor androoftrussesandmetalframinganchorsprovidesevengreaterrigidityandpermitswiderspacingoffloorandroof supporting members.FOUNDATIONSAfirmfoundation,consistingofproperlyinstalledfootings of adequate size to support the structure, is es-sentialtothesatisfactoryperformanceofallbuildings.Such foundations fully utilize the strength and resilienceof wood frame construction.Footingsshouldextendbelowexteriorgradesuffi-ciently to be free of frost action during winter months. Whereroots of trees are removed during excavation or when build-ing on filled ground, the ground should be well compactedbefore footings are installed or concrete is poured.Wherepoorsoilconditionsexist,satisfactoryfoun-dations may be constructed of treated timber piles cappedwith wood or concrete sills. Footing requirements are cov-eredinthelocalbuildingcode.Itisgoodpractice,generally, to make the footing thickness equal to the thick-ness of the foundation wall and the footing projection equalto one-half the foundation wall thickness.Two principal foundation types are commonly used.These are concrete and pressure preservative treated wood.Concrete footings with poured concrete or masonry blockfoundation walls are most common. An increasingly popu-lar foundation for houses and other wood frame buildingsis the Permanent Wood Foundation which is acceptedby all model building codes and the Department of Hous-ing and Urban Development (HUD).Concrete FoundationsConcrete footings are frequently unreinforced. Whereunstablesoilconditionsexist,however,reinforcedcon-creteisused.Thisrequiresengineeringanalysisofthefooting. The foundation wall may be of poured concreteor masonry blocks. Masonry block basement walls typi-cally have a -inch coat of Portland cement mortar appliedto the exterior. When set, the mortar parging is coveredwith two coats of asphalt to resist penetration of the wallis common practice to assemble wall framing on the floorand tilt the entire unit into place.BALLOON FRAMEInballoon-frameconstruction,exteriorwallstudscon-tinue through the first and second stories. First floor joists andexterior wall studs both bear on the anchored sill, Figure 2.Second-floor joists bear on a minimum 1x4-inch ribbon strip,which has been let-in to the inside edges of exterior wall studs.In two-story buildings with brick or stone veneer exte-riors, balloon framing reduces variations in settlement offraming and the masonry veneer. Where exterior walls areof solid masonry, balloon framing of interior bearing parti-tions also reduces distortions in door and closet openingsincrosswalls.Therequirementforlongerstuds,andthedifficulty in accommodating current erection practices andfirestopping, has reduced the popularity of this system.FASTENINGSNails, used alone or in combination with metal fram-inganchorsandconstructionadhesives,arethemostcommon method of fastening 1- and 2-inch framing lum-ber and sheathing panels, Figure 4. Ring or spiral shanknailsprovidehigherload-carryingcapacitiesthancom-mon nails of the same diameter, and are particularly usefulwhere greater withdrawal resistance is required.Nailed joints provide best performance where the loadacts at right angles to the nails. Nailed joints with the loadappliedparalleltothenail(inwithdrawal)shouldbeavoided wherever possible, since joints are weakest whennailed in this manner, Figure 3.Where tilt-up wall framing is not practical, or wherestronger stud-to-plate attachment is required (as in the useof rigid foam sheathing), toe-nailing is the most practicalmethod of framing studs and plates.Intoe-nailing,nailsaredrivenata30-degreeangle(approximately)tothestud.Studscanbepre-drilledtosimplify this operation and prevent excessive splitting.PLANK AND BEAM CONSTRUCTIONIn the plank and beam framing method, beams of ad-equate size to support floor and roof loads are spaced upto eight feet apart. Floors and roofs are covered with 2-inch planks. These serve as subflooring and roof sheathing,and, where tongue-and-grooved planking is used, providean attractive finished floor and ceiling.Ends of floor and roof beams are supported on postswhichprovidethewallframing.SupplementaryframingbetweenpostspermitsattachmentofwallsheathingandCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL6 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONbygroundwater,Figure5.Masonryblockwallsarecapped at the top with 4 inches of solid masonry or con-crete.Draintilesareinstalledaroundtheentirefootingperimeter of concrete foundations. These lead to a stormdrain or sump with pump to a positive drain.Wood FoundationsPermanent wood foundations are engineered systemsconsisting of wood framing and plywood sheathing thathave been pressure treated with heavy concentrations ofpreservative to assure freedom from decay and insect at-tack. Thesystemisusedwithbothbasementandcrawlspace foundations, Figures 6a and 6b.Permanent wood foundations are particularly suitablefor cold weather construction where the entire foundationsystemcanbeprefabricated.Thefootingandbasementarea consists of a layer of gravel or crushed stone of 4-inch minimum thickness. Treated wood footing plates ofadequate thickness and width are placed on the stone baseat the wall perimeter. These support foundation stud wallsof treated lumber framing and plywood sheathing whichhave been designed to support vertical and lateral loads.Exterior plywood joints are caulked and basement foun-dation walls are covered with 6-mil polyethylene film todirect ground water to the gravel base. Basement floorsare concrete slab or wood flooring laid on treated woodjoists on sleepers. A 6-mil polyethylene film is placed overthe gravel base beneath the slab or wood floor.Drain tiles are not required with permanent wood foun-dations. Ground water at the wall perimeter drains throughthe gravel footing and the gravel slab base to a sump whichleadstoadaylightoutletorispumpedtoastormdrain,Figure 7. Such basements have a superior record for main-tainingdryinteriorconditions. AdditionalinformationonPermanent Wood Foundations is available from AF&PA andthe Southern Pine Council (Appendix, Items 6 and 7).Other FoundationsOtherfoundationtypesincludefreestandingpiers,piers with curtain walls, or piers supporting grade beams.Piers and their footings must be of adequate size to carrythe weight of the house, contents and occupants. Pier spac-ing will depend upon arrangement of floor framing andlocationofbearingwallsandpartitions.Spacingintherange of 8 to 12 feet is common practice, Figure 8.PROTECTION AGAINST TERMITES ANDDECAYGoodconstructionpracticepreventsconditionsthatcould lead to decay or termite attack. Details for termiteand decay prevention are found in Design of Wood Struc-turesforPermanence-WoodConstructionDataNo.6(Appendix, Item 8). The following practices are basic:All roots and scraps of lumber are removed from theimmediate vicinity of the house before backfilling.Loosebackfilliscarefullytampedtoreducesettle-mentaroundthefoundationperimeter.Gradingatthefoundation and over the building site is sloped to providedrainage away from the structure.Unexcavated SpacesExposed ground in crawl spaces and under porches ordecks is covered with 6-mil polyethylene film. Minimumclearance between the ground and the bottom edge of beamsor girders is at least twelve inches. Clearance between thebottomofwoodjoistsorastructuralplankfloorandtheground is a minimum of 18 inches, Figure 9. Where it isnot possible to maintain these clearances, approved1 pres-sure treated or naturally durable wood species are used.Columns and PostsPosts or columns in basements and cellars, or exposedto the weather, are supported by concrete piers or pedestalsprojectingatleast1inchaboveconcretefloorsordecksand6inchesaboveexposedearth.Woodpostsandcol-umns are separated from concrete piers by an imperviousmoisture barrier, except when approved pressure treated ornaturally durable wood species are used, Figures 9 and 10.Wood posts or columns which are closer than 8 inchesto exposed ground in crawl spaces or supporting porchesor decks are of approved pressure treated or naturally du-rable wood species.Exterior wallsWoodframingandsheathingusedinexteriorwallsareinstalledatleast8inchesaboveexposedearth(in-cluding finished grade), unless approved pressure treatedornaturallydurablewoodspeciesareused,Figures11and 12.Beams and Girders in Masonry WallsOpeningsorcavitiesinmasonrywallstosupporttheends of beams, girders, or floor joists are of sufficient size toprovide a minimum of -inch clearance at the top, sides andends of such members, unless pressure preservative treatedor naturally durable wood species are used, Figure 12.Wood Supports Embedded in GroundWoodsupportsembeddedinthegroundtosupportpermanent structures shall be treated with approved pres-surepreservativetreatments.Woodposts,polesandcolumns which support permanent structures and which1 Approved, as used in this text, means approved by the authority having jurisdiction.Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION7 WOOD CONSTRUCTION DATA 1are embedded in concrete in direct contact with earth orexposedtotheweather,shallbetreatedwithapprovedpressure preservative treatments.SidingA minimum clearance of 6 inches is maintained be-tween the finished grade and the bottom edge of all typesofsidingusedwithwoodframebuildings.Suchclear-ancepermitsreadyinspectionfortermiteactivityandimproved performance of exterior paint and stain finishes.Crawl Space VentilationCrawlspacesareventedbyopeningsinfoundationwalls. The number and size of such vent openings are de-termined to provide a minimum total vent area equal to1/150 of the crawl space ground area. For example, a 1500sq.ft.groundareawouldrequireatotalof10sq.ft.ofventedopening,or10vents,each1squarefootinnetopening size. Corrosion resistant mesh with -inch maxi-mum openings is recommended.A 6-mil plastic film ground cover in the crawl spacereduces the required amount of ventilation to 10 percentoftheprecedingrecommendation.Withgroundcoverprotection, vents may have operable louvers. Vent open-ingsshouldbeplacedtoprovidecrossventilationandoccur within 3 feet of corners.Termite ControlAfterremovalofallscrapwoodfromthebuildingperimeter, treatment of the soil around the foundation withanapprovedtermiticideisthemosteffectiveprotectionagainst subterranean termites. Properly installed termiteshields also provide protection where the interiors of foun-dation walls are not easily inspected, Figure 13.Additional RequirementsIn geographical areas where experience has demon-stratedaneedformoreprotectivemeasures,therequirements of the preceding paragraphs may be modi-fied to the extent required by local conditions.FLOOR FRAMINGFloorframingconsistsofasystemofsills,girders,joists or floor trusses and sub-flooring that provides sup-portforfloorloadsandgiveslateralsupporttoexteriorwalls.Sills on Foundation WallsSills resting on continuous masonry foundation wallsare generally of nominal 2x4 or 2x6 lumber. They are an-choredtomasonrywallswith-inchboltsatapproximately 6-foot intervals. Bolts are embedded at least6 inches in poured concrete walls and at least 15 inches inmasonryblockwalls,Figure14.Metalanchorstraps,embeddedinfoundationwallsatsufficientintervalstopermit adequate nail fastening to sills, may also be used.Sills on PiersSills supported by free-standing piers must be of ad-equate size to carry all imposed loads between piers. Theymay be of solid wood or of built-up construction such asdescribed for beams and girders. Sills are anchored to pierswith-inchboltsembeddedatleast6inchesinpouredconcrete and at least 15 inches in masonry block, Figure 8.Beams and GirdersBeams and girders are of solid timber or built-up con-struction in which multiple pieces of nominal 2-inch thicklumberarenailedtogetherwiththewidefacesvertical.Suchpiecesarenailedwithtworowsof20dnails-onerow near the top edge and the other near the bottom edge.Nails in each row are spaced 32 inches apart. End jointsofthenailedlumbershouldoccuroverthesupportingcolumn or pier. End joints in adjacent pieces should be atleast 16 inches apart, Figure 15. Glued-laminated mem-bersarealsoused.Beamsandgirdersthatarenotcontinuous are tied together across supports. Bearing ofat least 4 inches is required at supports.Selection and Placing of JoistsSpan Tables for Joists and Rafters (Appendix, Item 4)published by the American Forest & Paper Association,provides maximum allowable spans for the different spe-cies and grades of lumber depending upon floor and roofdesign loads and spacing of the members.Joist end-bearing should not be less than 1 incheson wood or metal and 3 inches on masonry. Joists are usu-ally attached to sills by two toe-nails, or by metal framinganchors, Figures 8, 11 and 16.Joists should be placed sothe top edge provides an even plane for the sub-floor andfinished floor. It is preferable to frame joists into the sidesofgirderstoreducethecumulativeeffectofseasoningshrinkage, Figures 17, 18, 19 and 20.BridgingAdequately nailed subflooring will maintain the up-per edges of floor joists in proper alignment. Nailing theendsofjoiststobandjoistsorheaders,Figures11and24,providesadditionaljoistsupportthat,undernormalconditions, eliminates the need for intermediate bridging.Where the nominal depth-to-thickness ratio of joists ex-ceeds6,orwherebuildershaveencounteredproblemswith twisting of joists in service, intermediate joist bridg-Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL8 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONing is installed at 8-foot intervals. Bridging may also beaccomplished with cross braces of nominal 1x4-inch lum-ber or solid 2-inch lumber, Figures 21 and 22.Framing of Floor OpeningsHeaders, trimmers and tail joists form the framing forfloor openings. Trimmers and headers are doubled whenthe header span exceeds 4 feet. Headers more than 6 feetinlengtharesupportedattheendsbyjoisthangersorframinganchorsunlesstheyarebearingonapartition,beam or wall. Tail joists which exceed 12 feet in lengthare supported on framing anchors or on ledger strips notless than nominal 2x2 inches, Figures 23, 24 and 25.Notching and Boring of JoistsNotches or holes in joists for plumbing or wiring shallnot be cut in the middle one-third of the joist span. Notchesin the outer-third sections of the span may be no greaterthan one-sixth the joist depth. Where notches are made atthe joist ends for ledger support, they may be no greaterthanone-fourththejoistdepth.Holesinthejoistareare limited in diameter to one-third the joist depth and arecutwith the edgeof the holeno closer than2 inches tothe top or bottom edges, Figure 26.Support of PartitionsBearingpartitionsarenormallyplacedovergirdersor walls which support the floor system. Where floor fram-ing is adequate to support the added load, bearing partitionsmay be offset from supporting members by no more thanthejoistdepth,unlessfloorjoistsaredesignedtocarrythe increased load, Figures 27 and 28.Wherenon-bearingpartitionsrunparalleltofloorjoists, the joist under the partition is doubled to supportincreasedloadswhichfrequentlyoccuradjacenttothepartition, Figures 29 and 30.Overhang of FloorsWhere second-floor joists project over the first storywall at right angles, they are cantilevered to support thesecond story wall, Figure 35. Where the overhanging wallisparalleltothesecondfloorjoists,adoublejoistsup-ports lookout joists which extend at right angles over thefirststorywall,Figure36.Thedoublejoistislocatedinside the supporting wall at a distance equal to twice theoverhang. Lookout joists are framed into the double joistby framing anchors or a ledger strip nailed at the upperedge.FIRESTOPPINGAll concealed spaces in wood framing are firestoppedwith wood blocking or other approved materials. Block-ingmustbeaccuratelyfittedtofilltheopeningandtoprevent drafts between spaces, Figures 2, 16, 27, 28, 31,and 32.Openings around vents, pipes, ducts, chimneys, fire-places and similar fixtures which would allow passage offire are filled with non-combustible material, Figure 37.Otherfirestoppingrequires2-inchlumberortwothicknesses of 1-inch lumber with staggered joints, or onethickness of -inch plywood with joints backed by 1-inchlumber or -inch plywood.Sillsandplatesnormallyprovideadequatefirestopping in walls and partitions. However, stopping isrequired at all intersections between vertical and horizon-tal spaces such as occur at soffits, dropped ceilings andcoved ceilings, Figure 38.Furred spaces on masonry walls are firestopped at eachfloor level and at the ceiling level by wood blocking or bynon-combustible material of sufficient thickness to fill thespace, Figure 39.DRAFTSTOPPINGIn single family residences, draftstopping is requiredparallel to main framing members in floor/ceiling assem-bliesseparatingusablespacesintotwoormoreapproximately equal areas with no area greater than 500square feet. Materials for draftstopping may be 3/8-inchplywood or -inch gypsum board, Figure 40.EXTERIOR WALL FRAMINGExteriorwallframingmustbeofadequatesizeandstrength to support floor and roof loads. Walls must alsoresist lateral wind loads and, in some locations, earthquakeforces. Top plates are doubled and lapped at corners andat bearing partition intersections to tie the building into astrong structural unit. A single top plate may beused whereroof rafters or trusses bear directly above wall studs. Insuch cases adequate corner ties are required, particularlywhere non-structural sheathing is used.Stud Size and SpacingStuds in exterior walls of one and two-story buildingsare at least nominal 2x4 inches with the 4-inch dimensionforming the basic wall thickness. Stud spacing is normally16 inches in exterior walls, although 24-inch spacing of2x4studsisacceptableinone-storybuildingsifwallsheathingorsidingisofadequatethicknesstobridgeCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION9 WOOD CONSTRUCTION DATA 1across studs.In three-story buildings studs in the bottomstory are at least nominal 3x4 or 2x6 inches and may notexceed 16-inch spacing.Studs are arranged in multiples at corners and parti-tionintersectionstoprovideforrigidattachmentofsheathing, siding and interior wall finish materials. Nail-ing strips or metal clips may be used to back up interiorfinish at corners, Figures 41 and 42.Exterior Wall OpeningsA header of adequate size is required at window anddoor openings to carry vertical loads across the opening.Headers may be supported by doubled studs or, where thespan does not exceed 3 feet, framing anchors may be usedwith single supporting studs, Figures 43 and 44. Wheretheopeningwidthexceeds6feet,triplestudsareusedwith each end of the header bearing on two studs.Gable End WallsStudsatgableendsbearonthetopplateandarenotched and nailed to the end rafter, Figure 46.Wall SheathingThehighresistanceofwoodframeconstructiontohurricane,earthquakeandotherforcesofnatureispro-videdwhenwoodsheathingisadequatelynailedtotheoutside edges of exterior wall studs, plates and headers.Wall sheathing includes plywood, particleboard and otherstructuralpanelssuchaswafer-board,oriented-strandboard, structural insulation board and one-inch board lum-ber.Suchsheathingisappliedinstrictaccordancewithmanufacturersnailingrequirementstoprovidearigid,yet resilient, wood frame system. Some structural panelsfunction as both sheathing and siding.Where the building exterior is to be stuccoed, whereplasticfoamsheathingisused,orwherebevelorotherlap siding is applied directly to the studs, exterior wallsmust be braced at the corners with 1x4 lumber which hasbeen let-in to the outside surfaces of studs, plates andheaders at an angle of 45 degrees, Figures 1 and 2. Metalstrap braces adequately nailed may be used. Plywood orotherstructuralpanelsappliedverticallyateachcorneralsoserveasadequatecornerbracingwherenon-struc-tural sheathing is otherwise used.Building or Sheathing PaperWalls are protected from wind and water infiltrationbycoveringthewallsheathingwithalayerofType15asphaltsaturatedfeltpaperorwithothersuitablewaterrepellent paper or plastic films. Such coverings must per-mit passage of any moisture vapor which enters the wallsystemfromtheinteriorandhaveavaporpermeabilityrating of five or greater. Six-inch wide strips of sheathingpaper are applied around all wall openings and behind allexterior trim, Figures 49 and 50. Sheathing paper is ap-plied from the bottom of the wall, lapping horizontal joints4 inches and vertical joints 6 inches.INTERIOR PARTITION FRAMINGThere are two types of interior partitions: bearing par-titionswhichsupportfloors,ceilingsorroofs;andnon-bearing partitions which carry only the weight of thematerials in the partition, including attachments in the fin-ished building.Bearing PartitionsStuds in bearing partitions should be at least nominal2x4 inches, with the wide surface of the stud at right anglesto top and bottom plates or headers. Plates are lapped ortied into exterior walls at intersection points.Single top plates are permitted where joists or raftersare supported directly over bearing wall studs. Studs sup-portingfloorsarespacedamaximumof16inchesoncenter. Studs supporting ceilings may be spaced 24 incheson center. Headers in bearing walls are used to carry loadsover openings, as required for exterior walls.Non-Bearing PartitionsStudsinnon-bearingpartitionsarenominal2x3or2x4 inches and may be installed with the wide face per-pendicular or parallel to the wall surface. Single top platesare used. Stud spacing is 16-or 24-inches on center as re-quired by the wall covering.FRAMING AROUND CHIMNEYS ANDFIREPLACESFramingWood framing must be adequately separated from fire-placeandchimneymasonry,Figures47aand47b.Allheaders, beams, joists and studs must be kept at least twoinchesfromtheoutsidefaceofchimneyandfireplacemasonry.Prefabricatedmetalfireplaceandchimneyas-sembliesaretobeinstalledinaccordancewiththemanufacturers recommendations and must be approvedby the code authority.TrimWood mantles and similar trim are separated from fire-place openings by at least six inches, Figures 48a and 48b.Wherecombustiblematerialiswithin12inchesofthefireplace opening, the projection shall not exceed inchfor each 1-inch distance from such opening.Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL10 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONROOF AND CEILING FRAMINGRoofconstructionmustbeofadequatestrengthtowithstand anticipated snow and wind loads. Framing mem-bers must be securely fastened to each other, to sheathingand to exterior walls to enable the roof system to serve asa structural unit, Figures 51 through 59.Ceiling Joist and Rafter FramingMaximum allowable spans for ceiling joists and raftersfor various lumber grades and species are provided in SpanTables for Joists and Rafters, (Appendix, Item 4).Ceiling joists must be securely nailed to exterior wallplates, to the ends of rafters and where the joists join overinterior partitions. This provides a structural tie across thebuilding to withstand outward forces exerted by the rafters,Figure 51. Ceiling joists at right angles to rafters are to beavoided, Figure 52.The ridge member is of 1- or 2-inch thick lumber andis 2 inches deeper than the depth of the rafters to permitfull bearing at the angled rafter ends. Rafters are placeddirectlyoppositeeachotheracrosstheridgeandarenotched at the lower end to fit the exterior wall top plate,Figures 53 and 57. Rafters are secured to the wall plateby toe-nailing or use of special metal plate fastenings.Collar Beams (collar ties)Collar beams of nominal 1x6or 2x4 lumber are in-stalled in the upper one-third of the attic space to everythird pair of rafters to secure the ridge framing.Valley and Hip Rafter FramingValley rafters at the intersection of two roof areas aredoubled in thickness and two inches deeper than adjoin-ing rafters, Figure 55.Hip rafters are of single thickness but are two inchesdeeper than common rafters to permit full bearing of jackrafters, Figure 56.Where ridges occur at different elevations, provisionmust be made for vertical support of the interior end ofthe lower ridge board.Roof TrussesRoof framing may be fabricated as light trusses andinstalled as complete units. Such framing is designed ac-cordingtoacceptedengineeringpractice.Thetrussmembersarejoinedtogetherbyfastenerssuchasnails,nailsandglue,bolts,metalplatesorotherframingde-vices.Useofrooftrusseseliminatestheneedforinteriorbearing partitions and frequently results in more rapid in-stallationofroofandceilingframing.Rooftrussesaregenerally spaced 24 inches on center.Where roof trusses are used, gable ends are usuallyframed in the conventional manner using a common rafterto which gable end studs are nailed. Eave overhangs areframed by extending the top chords of the trusses beyondthe wall.Where hip and valley construction is required, modi-fied trusses or conventional framing are used to meet thecondition.Ceiling-Floor-Partition SeparationIn some localities truss uplift may be a problem. Thisproblem is characterized by the separation of the floor orceiling from an interior partition.A widely used technique to minimize truss uplift sepa-ration is to allow the gypsum board ceiling to float orrest on the partition and remain unattached to the truss oneither side of the partition. In cases where trusses are per-pendicular to partitions, the gypsum board ceiling remainsunattached at least 18 inches from the ceiling/ wall inter-section, Figure 68. Additional solutions to this separationare found in two reports referenced in Appendix, Items12 and 13.Flat RoofsFlat roofs should be avoided if possible because theyare difficult to ventilate and insulate adequately and presentweatherproofingproblems.Whereflatroofsareused,rafters or roof joists serve as ceiling joists for the spacebelow, Figure 54. Maximum allowable spans for ceilingjoists and rafters are contained in Span Tables for Joistsand Rafters, (Appendix, Item 4). Flat roof joists are se-curely nailed to exterior wall plates and to each other wherethey join over interior partitions.Roof SheathingWood structural panels or 1-inch board lumber pro-videsasolidbaseforroofcoverings.Structuralpanelsare manufactured in various thicknesses and are usually4x8'insurfacedimension.Recommendedspans,spac-ingbetweenpaneledgesandthicknessarestampedonthe panel face. Structural panels are installed with the longdimension perpendicular to rafters and with the panel con-tinuous over two or more spans.Spaced SheathingWhere wood shingles or shakes are to be applied asthe finished roof, solid sheathing is used or nominal 1x4lumber is nailed perpendicular to rafters and trusses witheach board spaced a distance from the next board equal tothe weather exposure of the shingles or shakes. (5 inchesCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION11 WOOD CONSTRUCTION DATA 1is common exposure for shingles. Shakes may be exposed7 to 13 inches depending on their length.) Because shakesare not smooth surfaced, an 18-inch wide underlay of as-phalt felt is used between each course. Where wind drivensnow is encountered, solid sheathing and Type 15 asphaltfelt are used under wood shakes.Ventilation of Attic SpacesVentilation of all attic spaces is required to eliminatemoisturecondensationonroofframingincoldweatherand to permit heat to escape in warm weather, Figure 61.For gable roofs, a screened, louvered opening is usedwhich provides a net open area of 1/150 of the area of theceiling below. Where a -inch wide screened slot is alsoprovidedintheeavesoffits,orwhereavaporretarderhaving one perm or less permeability is installed on thewarm side of the ceiling, the total ventilating area may bereduced to 1/300 of the ceiling area.With hip roof construction, a -inch wide screenedslot in the eave soffits, and ventilator at the ridge to pro-vide 1/450 inlet and 1/900 outlet fractions of the ceilingarea below, assures adequate ventilation.Forflatroofs,blocking,bridgingandinsulationarearrangedtopreventobstructionofairflow.Suchroofsare ventilated at eave soffits to provide net open area equalto 1/250 of the area of the ceiling below. A vapor retarderof one perm or less permeability is applied under the ceil-ing finish below flat roofs.INSULATION AND VAPOR RETARDERSInsulationAdequate insulation in stud spaces of exterior walls,between floor and ceiling joists or rafters and on the in-side of masonry foundations between grade line and firstfloor, make wood frame construction efficient to heat andcool. It also increases occupant comfort and absorbs out-sidenoises.Rollorbatt-typeinsulationisinstalledfullthickness in exterior walls or between rafters. Roll or loosefill insulation is used in attics between ceiling joists. Rigidfoam plastic is bonded to the inside of foundation wallswith construction adhesive.Vapor RetardersVaporretardantfilmpreventsmoisturevaporfrommoving through the insulated wall and condensing on thebacksideofsheathingandsiding.Suchcondensationgreatly reduces the effectiveness of insulation and causesfailures of exterior paints and finishes.Wall insulation batts usually have vapor retardant pa-percoversfacingtheroominterior.However,themostcommonmethodofinstallingwallinsulationbattscre-ates gaps along each stud, which make this type of vaporprotection of little value. Proper vapor protection requiresa 4-mil (.004") minimum thickness of polyethylene filmstapled to wall studs immediately beneath the dry wall orotherinteriorfinish.Thefilmiscarefullyfittedaroundwindow and door openings and behind electric outlets.Crawlspacesandbasementconcreteslabsarealsosources of moisture vapor, which reduce the effectivenessofinsulationandcreateexpansionproblemswithhard-wood flooring. A 6-mil (.006") polyethylene film placedover the ground in crawl spaces and over the gravel be-forethebasementslabispouredisthemosteffectivemethod of controlling moisture vapor from the ground.Some plastic foam sheathings and foil-faced sheath-ing may act as vapor retarders on the outside of exteriorwalls. Where such sheathing panels are used, it is essen-tial that a vapor retardant polyethylene film be placed onthe inside wall surface, beneath the interior wall finish.EXTERIOR SIDING AND COVERINGSManytypesofwood,hardboard,shingle,structuralpanel,metalandmasonryveneersidingsareusedoverwood framing. Such materials are separated from the fi-nal, finished grade by a minimum of 6 inches, Figure 49.Wood SidingA variety of wood and hardboard siding patterns areavailable. Bevel, shiplap and drop types are generally usedhorizontally.Board-and-batten,board-on-boardandtonguedandgroovedboardsareappliedvertically,Figure 63. Surfaces are smooth, rough sawn or overlaidwith paper or plastic film. They may be natural or factorypre-primed or pre-finished.SidingandexteriortrimareappliedoveralayerofType15asphaltfeltorotherwaterrepellentsheathingcover with corrosion-resistant nails. Hot dipped galvanizedsteel, stainless steel or aluminum nails may be used. Naillength varies with the thickness of siding and sheathing.Forsmoothshanksidingnails,requiredlengthisdeter-minedbyaddingtothecombinedsidingandsheathingthickness an additional 1 inches for penetration into solidwood.Where foam sheathing or insulation board sheathingareused,solidwoodmeans1-inchnailpenetrationintothestud.However,whereplywood,waferboardororiented strand board sheathing are used, the thickness ofthesepanelsbecomesapartofthe1-inchsolidwoodnail penetration.Ring-shank or spiral-shank siding nails have additionalholding power. A reduction of 1/8 to 1/4 inch in requirednail penetration into solid wood is permitted for these fas-Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL12 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONteners. Additionalrequirementsapplytouseofrigidfoamplasticsheathing,andarepublishedby AF&PA(Appendix, Item 9).Bevelsidingandsquareedgedboardsappliedhori-zontallyarenailedwithasinglenailateachstud.Theminimum lap is 1 inch, with the nail driven approximately1 inches above the lap, Figure 63(a).Drop and shiplap type sidings, which lay flush againstthe sheathing paper, are nailed at each stud with a singlenail approximately 1 inches above the drip edge. Wheresidingwidthis8inchesormoreorwheresheathingisomitted, two nails are used, Figure 63(b).Cornertreatmentisgovernedbythehousedesign.Cornerboards,miteredcorners,metalcornercoversoralternately lapped corners are used, Figure 64.Boardsiding,bothsquareedgeandtongueandgrooved,isappliedvertically,Figures63(c)and63(d).Wherewood,plywoodorstructuralpanelsheathingof-inchminimumthicknessisused,nailsarespaced16inches vertically. For other types of sheathing, horizontalnominal 1x4-inch furring strips are applied at 24-inch in-tervals as a nail base for vertical siding application. Wherestud spacing exceeds 16 inches, inter-stud blocking with2-inch lumber between studs is required.Protection of SidingEnds of wood siding at corners, butt joints and at jointswith window and door trim are protected by an applica-tion of clear water repellent preservative. Dipping at thetimeofsidingapplicationorsubsequentbrushorspraytreatmentbeforecaulkingandpaintingareeffective.Where wood siding is to be left to weather unfinished, aliberal coat of clear water repellent preservative is appliedto the entire exterior siding surface.Wood Shingles and ShakesShinglesandshakesusedasexteriorwallcoveringare applied with the weather exposures in Table II.Shingles and shakes are nailed with corrosion resis-tant nails of sufficient length to penetrate wood sheathing.Two nails are used for widths up to 8 inches. For widershingles and shakes, three nails are used.With single course applications nails are driven oneinch above the butt line of the succeeding course. In doublecoursing the under course is attached to wood sheathingwiththreenailsorstaples.Theoutercourseisappliedwith small-headed nails driven approximately 1 inch abovethe butts and inch from the edges.Where other than wood, plywood, waferboard or ori-ented-strandboardsheathingisused,anailbaseof1x3-inch wood furring strips is applied horizontally at in-tervals equal to the weather exposure of the shingles orshakes, Figure 50.Masonry VeneerMasonry veneer applied to wood frame constructionis supported on the masonry foundation wall. Where per-manentwoodfoundationsareused,masonryveneerissupported on the preservative treated wood footing plateor on a preservative treated wood knee wall attached tothe wood foundation with corrosion resistant metal ties.Ties are spaced horizontally 24 inches on center, with eachtie supporting no more than two square feet of wall area.Tiesarefastenedthroughsheathingdirectlytofounda-tion studs, Figure 65.Inmasonryveneerapplicationstopermanentwoodfoundations, a 1-inch space is left between sheathing andmasonry. Base flashing extends from the outside face ofthe masonry wall over the foundation and up the sheath-ingaminimumdistanceof12inches.Weepholesareprovidedbyleavingopenverticaljointsat4-footinter-vals in the bottom course of masonry veneer.FLOORINGFlooring consists of the subfloor, underlayment and fin-ish floor. Depending upon the type of finish floor or subfloorused, underlayment may not be required. Where 25/32-inchtongue and grooved wood strip flooring is used, it may belaiddirectlyoverthesubfloor,Figure66.Wherelesserthicknesses of wood strip flooring are used, the thicknessand grade of subflooring must be adequate to support endjoints at full design load, unless they occur over joists.Underlayment is normally applied over the sub-floorwhereresilienttile,sheetvinylorcarpetisusedasthefinish floor surface.Sub-flooringThe sub-floor usually consists of plywood, particle-board or other wood structural panels, or board lumber.Lumbersub-flooringistypicallylaiddiagonallytoper-mitwoodstripfinishflooringtobelaideitherparallelwithoratrightanglesto,thefloorjoists.End-jointsinsub-flooring are cut to occur over joists.Wood structural panels are typically installed with thelong dimension at right angles to the joists and with thepanelcontinuousovertwoormorespans.Spacingbe-tween panels should be approximately 1/8 inch.UnderlaymentUnderlaymentpanelsareappliedoversub-flooringto provide a smooth surface for application of carpetingand other resilient floor coverings. Plywood underlaymentCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION13 WOOD CONSTRUCTION DATA 1requirements are covered by U.S. Product Standard PS 1-95,whichispublishedby APA-TheEngineeredWoodAssociation(Appendix,Item10).Hardboardunderlaymentrequirementsaresetforthin ANSI/AHAA135.4 (Appendix, Item 11) published by the AmericanHardboard Association. Application of finish floor cover-ingsisgenerallybyspecialistswhofollowthemanufacturers installation instructions for the carpet, re-silient tile or vinyl products.Wood FlooringHardwood and softwood strip flooring of -inch or25/32-inch thickness provides adequate strength and stiff-ness for direct application over sub-flooring at right anglesto joists. Where parquet (squares) are used or where stripflooring is laid parallel to joists, the grade and thicknessof sub-flooring panels must be adequate to provide sup-port between joists. An additional thickness of subflooringmay be required over the rough subfloor in such applica-tions.Woodstripflooringisnormallyappliedoverbuild-ing paper and is sanded and finished after installation. Anexpansion joint of at least one-half inch must be providedattheedgeofflooringstripsadjacenttoparallelparti-tionsandexteriorwalls.Thisjointiscoveredbythebaseplate and toe molding.WOOD DECKSWood decks are a special feature of many new housesand a useful add-on to others. Their capability for provid-ing additional low-cost living and recreational space makesit important to consider them as part of the original housedesign. Use of pressure treated and naturally durable lum-berhasmadetheseoutdoorstructuresaspermanentasthe house itself.Supporting joists, posts and decking lumber must beproperly grade marked and identified as naturally durableor pressure preservative treated wood by quality controlagenciesapprovedbythemodelbuildingcodesorthedwelling codes.DesignDeckshapeandsizeshouldbeconsistentwiththegeneral lines of the house and should be positioned to func-tionaspartofthetotalstructure.Orientationforsunexposure and shade is particularly important in locationof the deck.EngineeringCantilevered and other special deck types should beproperlyengineered.Fortypoundspersquarefootisaminimum design live load, considering the concentrationof people frequently supported by decks. The applicablecode will govern this requirement.Theinitialheaderjoistforthedeckisattachedtoaband or header joist of the house with through bolts or lagscrews, Figure 67. The level of the deck framing, includ-ing the 1-inch decking thickness is determined so thatthe deck surface is at least one inch below that of the inte-rior floor surface. If deck height is significantly differentfromthatofthebandorheaderjoistsofthehouse,thedeck header must be securely fastened to the wall studs.Joistsareattachedtotheheaderbypropertoe-nailing,preferably, by metal hangers to prevent splitting. Corro-sionresistanthangersandhot-dippedgalvanizedorstainless steel nails are required.Postlengthsaredeterminedafterdeckframinghasbeen supported on temporary 2x4 posts. For posts, pres-sure preservative treated for ground contact, footing holesare dug at required points. Concrete or gravel bases of 4-inch minimum thickness below the frost line are placedovercompactedsoilintheholes.Fromtheconcreteorgravel base required length of post to the deck level canbe determined.Footingsfornaturallydurablewoodpostsextend6inchesabovegrade.Pre-castconcretepiersorconcreteblock piers with imbedded -inch re-enforcing bar pinsortreatedwoodnailersareusedtosecurepostsagainstlateral movement, Figure 67.DeckingThefloorofthedeckisnormally2x4-inchor2x6-inch lumber. It is nailed with the end-grain showing thebark-side-up. Where pressure preservative treated lum-berorunseasonednaturallydurablelumberspeciesareused, decking pieces can be nailed in contact or spaced nofarther apart than a nail diameter. Kiln dried decking canbe laid with a maximum spacing of -inch.Decking nails must be good quality hot-dipped gal-vanized,aluminumorstainlesssteel. Two16dnailsaredriven at slight angles to each other at each joist position,Figure 67. Butt joints in 2x6 decking require three nails.RailingsRailingdesignsfollowthestyleofthehouse.Rail-ingsmustbesecurelyanchoredtothedeck,preferablyincluding an extension of the posts. Openings in the rail-ing are limited to six inches, or as the code requires.FinishesBoth pressure treated and naturally durable wood areresistanttodecayandinsects.However,agoodwater-repellent stain or paint finish will protect against checkingCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL14 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONand maintain the attractiveness of the deck. Applicationof a clear water repellent preservative immediately uponcompletion of the deck is recommended for both pressuretreated and naturally durable lumber.CONCLUSIONThe home is, for many families, the major investmentof a lifetime. While, in a mobile society, many familieswillhavelivedinseveralhomes,eachstructureshouldserve as a prized possession, capable of providing com-fortable shelter for a succession of satisfied occupants.Basic house construction follows simple engineeringprinciples.Inaddition,theworkmanshipofthehome,which involves carpentry and a number of other construc-tion trades, is in many ways a truly American art-form.This publication provides essential requirements for con-struction,andinformationtoassistinthedesign,construction and inspection of wood structures of provendurability and performance.Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION15 WOOD CONSTRUCTION DATA 1Table I. Nominal and Minimum-Dressed Sizes of Boards, Dimension andTimbers.aThe thicknesses apply to all widths and all widths apply to all thicknesses. Sizes are given in inches and millimeters. Metric units are based on dressed size - seeAppendix B, PS 20-99 for rounding rule.Thicknesses Face WidthsMinimum Dressed Minimum DressedNom. DrybGreenbNom. DrybGreenbinch inch mm inch mm inch inch mm inch mm2 1-1/2 38 1-9/16 403 2-1/2 64 2-9/16 654 3-1/2 89 3-9/16 905 4-1/2 114 4-5/8 1173/4 5/8 16 11/16 17 6 5-1/2 140 5-5/8 1431 3/4 19 25/32 20 7 6-1/2 165 6-5/8 168Boards 1-1/4 1 25 1-1/32 26 8 7-1/4 184 7-1/2 1901-1/2 1-1/4 32 1-9/32 33 9 8-1/4 210 8-1/2 21610 9-1/4 235 9-1/2 24111 10-1/4 260 10-1/2 26712 11-1/4 286 11-1/2 29214 13-1/4 337 13-1/2 34316 15-1/4 387 15-1/2 3942 1-1/2 38 1-9/16 402-1/2 2 51 2-1/16 523 2-1/2 64 2-9/16 652 1-1/2 38 1-9/16 40 3-1/2 3 76 3-1/16 782-1/2 2 51 2-1/16 52 4 3-1/2 89 3-9/16 903 2-1/2 64 2-9/16 65 4-1/2 4 102 4-1/16 103Dimension 3-1/2 3 76 3-1/16 78 5 4-1/2 114 4-5/8 1174 3-1/2 89 3-9/16 90 6 5-1/2 140 5-5/8 1434-1/2 4 102 4-1/16 103 8 7-1/4 184 7-1/2 19010 9-1/4 235 9-1/2 24112 11-1/4 286 11-1/2 29214 13-1/4 337 13-1/2 34316 15-1/4 387 15-1/2 394Timbers 5 & off 13 off 5 & off 13 offthicker wideraBased on Voluntary Product Standard DOC PS 20-99, American Softwood Lumber Standard. U.S. Department of Commerce. September 1999.bSee sections 2.7 and 2.11, PS 20-99 for the definitions of dry and green lumber.Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL16 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONShingle or Shake Maximum Weather ExposuresSingle-Coursing Double-CoursingLength and Type No. 1 No.2 No.1 No.21. 16-inch Shingles 7 7 12 102. 18-inch Shingles 8 8 14 113. 24-inch Shingles 11 11 16 144. 18-inch Resawn Shakes 8 14 5. 18-inch Straight-Split Shakes 8 16 6. 24-inch Resawn Shakes 11 20 Table II. Wood Shingle and Shake Weather ExposuresCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION17 WOOD CONSTRUCTION DATA 1Figure 1. Platform Frame ConstructionCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL18 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 2. Balloon Frame ConstructionFigure 3. Methods of Loading NailsCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION19 WOOD CONSTRUCTION DATA 1Figure 4. Sizes of Common Wire NailsNote: Print to scale to ensure accurate measurements. Do NOT check Fit to Page.Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL20 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 6a. Permanent Wood Foundation - Crawl spaceFigure 5. Masonry Foundation Wall and FootingCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION21 WOOD CONSTRUCTION DATA 1Figure 6b. Permanent Wood Foundation - BasementCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL22 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTION/O/L / /L O/ /// //// / O///O//2 2 //6/ ///L/L/ O/ 2O //6/ //L /L//6O// ///L O/ //L/L/ OO/ /O) / /L///////L/ /O/ //L6/ 6O/6/L/L ///L/O/LvL///6/ ///L / /L L)/L//L////O/q/ // /// 6/L/O/////q // //OO/Figure 7a. Sump for Poorly Drained SoilsFigure 7b. Sump for Medium to Well Drained SoilsCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION23 WOOD CONSTRUCTION DATA 1Figure 8. Pier Foundation andAnchorageFigure 9. Clearance Between Earthand Floor FramingFigure 10. Support for BasementPostCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL24 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 11. Floor Framing at ExteriorWallFigure 12. Girder Framing in ExteriorWallFigure 13. Termite ShieldsCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION25 WOOD CONSTRUCTION DATA 1Figure 14. Anchorage of Sill toFoundation WallFigure 16. Joist End BearingFigure 15. Nailing Built-up Beams andGirdersCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL26 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 17. Joist Supported on LedgerFigure 18. Joist Supported by MetalFraming AnchorsFigure 20. Joists Resting on SteelBeamFigure 19. Joists Resting on GirderCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION27 WOOD CONSTRUCTION DATA 1Figure 21. Diagonal Bridging of Floor JoistsFigure 22. Solid Bridging of Floor JoistsCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL28 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 23. Framing of Tail Joists onLedger StripFigure 24. Framing of Tail Joists byFraming AnchorsFigure 26. Notching and Boring ofJoistsFigure 25. Framing of Header toTrimmer by Joist HangersCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION29 WOOD CONSTRUCTION DATA 1Figure 27. Framing Over BearingPartition, PlatformConstructionFigure 28. Framing Over BearingPartition, BalloonConstructionCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL30 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 29. Framing Under Non-Bearing PartitionFigure 30. Attachment of Non-Bearing Partition to Ceiling FramingCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION31 WOOD CONSTRUCTION DATA 1Figure 31. Interior Stairway FramingCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL32 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 32. Stairway With a LandingFigure 33. Framing SupportingBathtubCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION33 WOOD CONSTRUCTION DATA 1Figure 34. Second Floor Framing,Exterior WallFigure 35. Second Floor Overhang ofExterior Wall, Joists atRight Angles toSupporting WallsFigure 36. Second Floor Overhang ofExterior Wall, JoistsParallel to SupportingWallsCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL34 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 37. Firestopping Around PipesFigure 38. Firestopping of Dropped CeilingsCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION35 WOOD CONSTRUCTION DATA 1Figure 39a. Firestopping of Masonry Walls - FloorFigure 39b. Firestopping of Masonry Walls - CeilingCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL36 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 40. Draftstopping of Trussed FloorsFigure 41. Multiple Studs at CornersFigure 42. Wall Framing atIntersecting PartitionsCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION37 WOOD CONSTRUCTION DATA 1Figure 43. Exterior Wall Openings,Header Details withCripple StudsFigure 44. Exterior Wall Openings,Header Details with JoistHangersCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL38 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 45. Framing of Bay WindowFigure 46. Wall Framing at GableEndsCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION39 WOOD CONSTRUCTION DATA 1Figure 47a. Wall and Floor Framing at Fireplace Figure 47b. Hearth Centering DetailCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL40 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 48a. Clearance of Fireplace TrimFigure 48b. Section Through MantleCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION41 WOOD CONSTRUCTION DATA 1Figure 49. Building Paper and Siding ApplicationFigure 50. Application of Wood ShinglesCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL42 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 51. Roof Framing Ceiling Joists Parallel to RaftersFigure 52. Roof Framing, CeilingJoists Perpendicular toRaftersCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION43 WOOD CONSTRUCTION DATA 1Figure 53. Roof Framing Gable OverhangFigure 54. Flat Roof FramingCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL44 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 55. Valley Rafter RoofFramingFigure 56. Hip Rafter Roof FramingFigure 57. Roof Framing at EaveCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION45 WOOD CONSTRUCTION DATA 1Figure 58. Shed Dormer Roof FramingCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL46 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 59. Gable Dormer FramingFigure 60. Roof Framing AroundChimneyCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION47 WOOD CONSTRUCTION DATA 1Figure 61. Roof Ventilation RequirementsFigure 62. Ventilating Eave OverhangsCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL48 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 63. Wood Siding Patterns and NailingFigure 64. Corner Treatments for Wood Sidinga)b)c)d)Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION49 WOOD CONSTRUCTION DATA 1Figure 65. Application of Masonry Veneer to Wood FramingFigure 66. Wood Strip FlooringCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL50 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONFigure 67. Wood DeckCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN FOREST & PAPER ASSOCIATION51 WOOD CONSTRUCTION DATA 1Figure 68. Ceiling-Floor Partition SeparationCopyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.AMERICAN WOOD COUNCIL52 DETAILS FOR CONVENTIONAL WOOD FRAME CONSTRUCTIONAPPENDIX1. Wood Frame Construction Manual for One- and Two-Family Dwellings, American Forest & PaperAssociation, 1111 19th Street, N.W., Suite 800, Washington, D.C. 20036.2. American Softwood Lumber Standard, PS 20-99; U.S. Dept. of Commerce, National Institute ofStandards and Technology, U.S. Government Printing Office, Washington, D.C. 20402.3. National Design Specification for Wood Construction, American Forest & Paper Association, 1111 19thStreet, N.W., Suite 800, Washington, D.C. 20036.4. Span Tables for Joists and Rafters, American Forest & Paper Association, 1111 19th Street, N.W., Suite800, Washington, D.C. 20036.5. Plank and Beam Framing for Residential Buildings- Wood Construction Data No. 4, American Forest &Paper Association, 1111 19th Street, N.W., Suite 800, Washington, D.C. 20036.6. Permanent Wood Foundation System-Basic Requirements, Technical Report No. 7, American Forest &Paper Association, 1111 19th Street, N.W., Suite 800, Washington, D.C. 20036.7. Permanent Wood Foundation Design and Construction Guide, Southern Forest Products Association,P. O. Box 641700, Kenner, LA 70064.8. Design of Wood Structures for Permanence-Wood Construction Data No. 6, American Forest & PaperAssociation, 1111 19th Street, N.W., Suite 800, Washington, D.C. 20036.9. Recommendations for Installing and Finishing Wood and Hardboard Siding Over Rigid FoamSheathing, American Forest & Paper Association, 1111 19th Street, N.W., Suite 800, Washington, D.C.20036.10. U.S. Product Standard PS1-95 Construction and Industrial Plywood, APA-The Engineered WoodAssociation, P.O. Box 11700, Tacoma, Washington, 98411.11. Basic Hardboard ANSI/AHA Standard A135.4, American Hardboard Association, 1210 W. NorthwestHwy, Palatine, IL 60067.12. Research Report 82-2:Ceiling-Floor Partition Separation in Light Frame Construction, Truss PlateInstitute, 583 DOnofrio Dr., Madison, WI 53719.13. Partition Separation Prevention and Solutions, Wood Truss Council of America, 6300 Enterprise Lane,Madison, WI 53719Copyright American Wood Council. Downloaded/printed pursuant to License Agreement. No further reproductions authorized.Amerlcan Forest & aer AssoclatlonAmerlcan Wood Councll1111 19th 5treet, NW5ulte 800Washlngton, bC 20036hone: 202-463-4113Fax: 202-463-2191emall: awclnfoafanda.orgweb: htt:,,www.awc.org