Three Options for Raised Wood Floors

1. Three Options forRaised Wood Floor Foundations
Sponsored by the
Southern
Pine Council
Introduction by
Russell Richardson
2. AIA BestPractices
This course is provided by the Southern Pine Council, a Registered Provider with the American Institute of Architects Continuing Education Systems (AIA/CES). Credit earned upon completion of this program will be reported to CES Records for all AIA members. Certificates of completion are available for non-members for self-reporting and recordkeeping purposes.

This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing or dealing in any material product.

Questions related to specific materials, methods and services presented in the learning unit should be directed to the Southern Pine Council upon completion of this program.
3. Copyright
2011, Southern Forest Products Association
This program is protected by U.S. and international copyright laws. Reproduction and distribution of this presentation without the expressed, written consent of the Southern Forest Products Association is prohibited.
4. Learning Objectives
Discuss the concept and design of a raised home with a wood pony (or stemwall) system
Discuss the concept and design of a raised home with a CMU pier system
Explain the concept and design of a raised home with a poured-concrete pier system
List three insulation options for a raised wood floor home
5. Three Homes, Three Foundations
How the houses featured in this course came to be.
Discuss the concept and design of a raisedhome with a wood pony (or stemwall) system
List three insulation options for a raised-floor
home
7. Pony Wall System

Scrub site 8. Bring in fill 9. Set forms 10. Grade beam level around perimeter

Site Preparation
11. Pony Wall System

Raised 3.5 inches above perimeter 12. Elevated interior grade allows water to drain off to exterior

Interior spot pads
13. Interior pad
Rebar in bottom
Pony Wall System
3.5-inch extension

Engineering determines how wide and how deep and how much rebar needed 15. Porch footings less deep 16. Get most uplift and weight on exterior perimeter

Porch Footing
Forms for footings set

To keep boltstraight in wet concrete 18. Anchor bolts help provide continuous load path 19. Attached to 1 x 4

Anchor bolt strategy

Eliminates need for sewer drain pipe to go across top of grade beam 21. 4-inch main from house slips into sleeve and out to sewer tie-in 22. Better appearance; requires no trimming of vegetation around pipe

6-inch PVC sleeve inside grade beam form
Concrete poured and forms taken down
All wood and debris will be removed
Ready for sand and compaction

Ready for sand compaction 25. Moisture absorbs into sand 26. Sand dries better than dirt 27. Drier conditions for working under the house in the future

Sand fill inside perimeter grade beam
Concrete slab poured for cars and storage
Anchor bolts in place. Sloped to drain water off to perimeter.
Pony wall

2 x 4 30. Pressure-treated Southern Pine 31. 24 inches on center 32. Double top plate 33. Single bottom plate

6 x 6 34. Notched for girder

Pony wall and post
35. Bottom plate with sill seal product added
Prevents moisture migration from concrete to plate
Pony Wall System
Need photo here from Roy of bottom plate with sill seal

Gravity load only 37. Post notched to hold one 2 x 12 38. Second 2 x 12 bolted in place 39. Ready for floor joists

Girders lag-bolted on notch in 6 x 6
Interior girder intersecting with pony wall
Ready for floor joists
Floor joists

2 x 8 42. 16 inches on center 43. Pony wall sitting on grade beam 44. Anchored to concrete slab

Floor joists installed
Blocking or bridging for floor joists

Blocking at mid-point of 14-foot span 46. Blocking between floor joists helps prevent joists from twisting 47. 2 x 8 pressure-treated Southern Pine

Pony Wall System

Cantilevered section to get extra floor space over perimeter pony wall 48. Blocking over bearing wall

Cantilevered floor section

Pressure-treated Southern Pine 50. Costs a few hundred

dollars more
Pressure-treated Southern Pine
51. Plywood subfloor
Pony Wall System

4 x 8, -inch plywood 52. Tongue and groove 53. Secured on all joists with adhesive and screws

Certified Wood Products
SFI Sustainable Forestry Initiative
Pony Wall System

Plates dont need to be treated as they would on a slab foundation 55. Sill seal or adhesive under exterior plates prevents air infiltration

Laying out walls

Pony wall system for sheer value and uplift 57. Extended length OSB panels 58. Uplift from bottom plate to top plate

Treated plywood on treated pony wall
Metal rod for uplift requirements
Lesson Learned:
With double bottom plate and nailing pattern, metal rod not necessary
60. Utility lines under house
Crawl space provides space to work under house
Pony Wall System
61. Finished home on pony wall system
Pony Wall System
Discuss the concept and design of a raised
home with a wood pony (or stemwall) system
Discuss the concept and design of a raised home with a CMU/brick pier system
List three insulation options for a raised-floor home
63. Footings for perimeter grade beam
Rebar tied into grade beam
CMU/Brick Pier System
64. CMU/Brick Pier System
Rebar in position
Ready to pour concrete

Rebar in grade beam for pier construction 66. Interior spot pads have no rebar 67. Load on interior pads for gravity only with no wind or sheer requirements

Concrete poured
68. CMU in place
Cells ready to be filled with concrete
69. CMU cells back filled
Rebar in concrete strong to deflect movement

Space around rebar determined by engineering 71. Strength comes from rebar and concrete, not the brick

Brick pier with rebar
72. Pressure-treated 2 x 8 on CMU pier
Anchor bolt through lumber for hold-down for girder
73. Pressure-treated 2 x 12 girders
Second 2 x 12 girder set in place
Atop 2 x 8
Floor joists on top of girders

2 x 10, 24 inches on-center 76. Same support as 2 x 8, 16 inches on-center used in pony wall system

Anchor bolts attached to hold-down
Lag bolts or lag screws through members
77. Floor system
2 x 6 used for interior pier eliminates need
to notch 6 x 6 to hold girder
78. Sand fill beneath house
79. Perimeter

Tongue-and- groove OSB subfloor 80. Base plate 81. Rim joist 82. 2 x 12 girder 83. Bottom plate 84. CMU pier 85. Perimeter footing

Extended length OSB

From top of top plate to below bottom plate 86. For sheer and uplift strength needed

Filled in OSB
Proper nailing and securing for continuous wood member
87. Finished home on CMU/brick pier system
Pressure-treated 1 x 6 boards allow air to flow freely,
but keeps out large pests
Explain the concept and design of a raised home with a poured-in-place pier system
List 3 insulation options for a raised-floor home
89. Forms set for exterior grade beam
Spot pads for interior
Poured-in-Place Pier System
90. Placement of vertical rebar critical
91. Pre-bent rebar secured
Held in place with 3/8-inch rebar
92. Poured-in-Place Pier System
-inch chamfer strips create angled corners on poured piers
Pier boxes made of plywood and 2 x 4 dimension lumber
Most cost-effective pier system
93. Alternatives are available to plywood boxes
94. Concrete poured into beam, piers and pads
Concrete finishers at work
95. Forms removed, site cleaned
Sand backfill in place
96. Piers with chamfer edges
Anchor bolts in place
Cement mix skimmed to fill imperfections
97. 2 x 8 plate topped by 2 x 12 girder
Added membrane acts as break to prevent moisture migration
98. 2 x 6 pieces nailed together for pier
On metal base with galvanized nails
Hold down lag-screwed to members
2 x 10 joists in place
Another alternative: hang joists from girders
100. Floor joists on top of girders
In flood zones, bottom of floor joists cannot be below flood elevation
101. Alternative: Hanging joists
Lowers elevation of building
102. Floor joists lapped over interior girder
Standard 4 x 8 OSB

Ran horizontally from bottom of rim board 104. Must block between stud framing in high-wind areas

3 types of porch decking:
5/4 x 6 Radius edge
1 x 4 tongue- and-groove
5/4 x 4tongue-and- groove
Note: KDAT (kiln dried after treatment) must be primed and painted before installation
Treated Southern Pine porch decking
105. Finished home on poured-in-place piers
List 3 insulation options for a raised-floor home
107. Fiberglass Batts
Used R-30, or 9 inches of insulation in 2 x 8 joists, Kraft paper UP against subfloor
Wire mesh across bottom of joists to hold it snug to subfloor
Insulation Options
108. Insulation Options
Spray foam
Rigid foam sheathing
2 thick foil-faced polyisocyanurate
109. Closed-cell spray foam
Insulation Options
Closed-cell (rather than open-cell) preferred for hot, humid climates
List three insulation options for a raised wood floor home
111. For more information:
SouthernPine.com

Three Options for Raised Wood Floors

Design

Transcript of Three Options for Raised Wood Floors