2009 IBS - High Performance Masonry Walls

High Performance High Performance Residential Residential

Masonry Walls Masonry Walls in the in the

2121stst Century Century

Presented by:Presented by:

Mike CoultonMike CoultonDirector of Product DevelopmentDirector of Product DevelopmentBenjamin Obdyke IncorporatedBenjamin Obdyke Incorporated

© 2008 Benjamin Obdyke Incorporated© 2008 Benjamin Obdyke Incorporated

AGENDAAGENDA

It’s about moisture managementIt’s about moisture management

Why now?Why now?

Case studyCase study

Solution optionsSolution options

Selecting the right solutionsSelecting the right solutions


IntroductionIntroduction

Need to incorporate good Need to incorporate good moisture management solutionsmoisture management solutions

– Ward off problems – occupant health Ward off problems – occupant health mold, rot, sustainabilitymold, rot, sustainability

– Energy efficiency of wallEnergy efficiency of wall

– Code changes – complianceCode changes – compliance


IntroductionIntroduction


Why Now?Why Now?

We’ve been building masonry We’ve been building masonry walls for centuries - why water walls for centuries - why water problems now?problems now?– Mass walls vs. veneer on wood framing Mass walls vs. veneer on wood framing

– Insulation practices – Energy crisis #1 Insulation practices – Energy crisis #1 (1970s) and #2 (2000s)(1970s) and #2 (2000s)


Why Now?Why Now?

Brick, stucco, stone walls have Brick, stucco, stone walls have always absorbed lots of moisture – always absorbed lots of moisture – very porousvery porous

Before tight envelopes (insulation and Before tight envelopes (insulation and water/air resistive barriers):water/air resistive barriers):– Winter – dried inside to outsideWinter – dried inside to outside

– Summer – dried outside to insideSummer – dried outside to inside


Why Now?Why Now?

Tightened building envelopes are Tightened building envelopes are great for saving energy, but bad great for saving energy, but bad for “drying” walls outfor “drying” walls out

OSB vs. planks or even plywoodOSB vs. planks or even plywood

Water-resistive (not water-proof) Water-resistive (not water-proof) and air-resistive barriersand air-resistive barriers


The NeedThe Need

Preserving the life of exterior framing Preserving the life of exterior framing and sheathing – sustainability.and sheathing – sustainability.

Reducing liability for callbacks, Reducing liability for callbacks, remediation, and litigation costs when remediation, and litigation costs when moisture damage occurs.moisture damage occurs.


The NeedThe Need

Complying with growing code Complying with growing code requirements:requirements: - IRC - Wall that “drains”IRC - Wall that “drains”

– Water resistive barrier requirementWater resistive barrier requirement

– State code requirements (MN, OR?)State code requirements (MN, OR?)

– Canadian codesCanadian codes


Code Changes / RequirementsCode Changes / Requirements

2006 IRC Section 703.12006 IRC Section 703.1

– ““The exterior wall envelope shall be designed The exterior wall envelope shall be designed and constructed in a manner that prevents the and constructed in a manner that prevents the accumulation of water within the wall accumulation of water within the wall assembly by providing a water-resistant assembly by providing a water-resistant barrier behind the exterior veneer as required barrier behind the exterior veneer as required by Section 703.2, and by Section 703.2, and a means of draining a means of draining water that enters the assembly to the water that enters the assembly to the exteriorexterior.” .”


2006 IRC Section 703.22006 IRC Section 703.2

– ““One layerOne layer of No. 15 asphalt felt, free from of No. 15 asphalt felt, free from holes and breaks, complying with ASTM D holes and breaks, complying with ASTM D 226 for Type I felt or other approved 226 for Type I felt or other approved water-water-resistive barrier shall be appliedresistive barrier shall be applied over studs or over studs or sheathing of sheathing of all exterior walls.” all exterior walls.”



2005 NBC of Canada Section 9.27.2.22005 NBC of Canada Section 9.27.2.2

– “…“…exterior walls exposed to precipitationexterior walls exposed to precipitation shall shall be protected against precipitation ingress by be protected against precipitation ingress by an exterior cladding assembly consisting of a an exterior cladding assembly consisting of a first plane of protection and first plane of protection and a second plane of a second plane of protection incorporating a capillary breakprotection incorporating a capillary break...”...”



2005 NBC of Canada Section 9.27.2.2 2005 NBC of Canada Section 9.27.2.2 (cont.)(cont.)

– “…“…a cladding assembly is deemed to have a a cladding assembly is deemed to have a capillary breakcapillary break between the cladding and the between the cladding and the backing assembly where …there is a backing assembly where …there is a drained drained and vented air space not less than 10mm deepand vented air space not less than 10mm deep behind the cladding, over the full height of the behind the cladding, over the full height of the wall…”wall…”



Case StudyCase Study

Homes on Philadelphia “Main Line”Homes on Philadelphia “Main Line”

Built within last 10 yearsBuilt within last 10 years

Moisture ProblemsMoisture Problems

RemediationRemediation



Cost to remediate $75,000 to Cost to remediate $75,000 to $300,000+$300,000+

Tear off cladding, WRB, Tear off cladding, WRB, sheathing, insulation, some sheathing, insulation, some framingframing

Do all this while occupied Do all this while occupied



Costs to prevent up-frontCosts to prevent up-front $1000 to $5000$1000 to $5000


Brick VeneerBrick Veneer

What can we learn from brick What can we learn from brick veneer?veneer?



Built with a space between Built with a space between cladding and sheathingcladding and sheathing

Built with drainage at bottom Built with drainage at bottom (need to keep clear)(need to keep clear)

Still uses WRB (one layer)Still uses WRB (one layer)


RainscreensRainscreens

A technique for controlling rain entry A technique for controlling rain entry in an exterior wall in an exterior wall

Involves locating an air space wide Involves locating an air space wide enough for capillary break enough for capillary break immediately behind the exterior immediately behind the exterior claddingcladding



When combined with openings at top When combined with openings at top and bottom, it creates a pressure and bottom, it creates a pressure equalized/moderated space to reduce equalized/moderated space to reduce forces leading to water entryforces leading to water entry

Water that does enter behind the Water that does enter behind the cladding is not in direct contact with cladding is not in direct contact with sheathing wallsheathing wall



The capillary break space – at least The capillary break space – at least 3/16” – can prevent surfactants from 3/16” – can prevent surfactants from damaging the water resistive barrierdamaging the water resistive barrier

Residual moisture is dried by air Residual moisture is dried by air movement (ventilation drying)movement (ventilation drying)



Ventilation drying can also assist in Ventilation drying can also assist in removing moisture vapor from inside removing moisture vapor from inside the building moving outward and from the building moving outward and from solar drive from wet claddings moving solar drive from wet claddings moving inward (remember those 2-way water inward (remember those 2-way water resistive barriers)resistive barriers)



Brick veneer constructionBrick veneer construction

Strapping or furring stripsStrapping or furring strips

Void space technology (“drainage Void space technology (“drainage mats”, “ventilation mats”, “rolled mats”, “ventilation mats”, “rolled rainscreens”) – 21rainscreens”) – 21stst century century



The chief advantage of strapping is in The chief advantage of strapping is in material costs – furring strips are less material costs – furring strips are less expensive than manufactured expensive than manufactured rainscreen productsrainscreen products

Installing these strips is labor-Installing these strips is labor-intensive and therefore strapping may intensive and therefore strapping may ultimately be more costly than void ultimately be more costly than void space productsspace products



Strapping covers about 15% of the wall Strapping covers about 15% of the wall surface leading to trapped moisturesurface leading to trapped moisture

Void space products are applied Void space products are applied continuously protecting the entire surface continuously protecting the entire surface area of the wall and providing a level area of the wall and providing a level surface for masonry applicationsurface for masonry application

Combination products provide the Combination products provide the rainscreen in same installation step as the rainscreen in same installation step as the housewrap, reducing laborhousewrap, reducing labor


ApplicationsApplications

How is this technology used in How is this technology used in masonry walls?masonry walls?


Applications – Brick VeneerApplications – Brick Veneer

Natural rainscreenNatural rainscreen

Must keep weep system “open” and Must keep weep system “open” and avoid clogging with mortar droppingsavoid clogging with mortar droppings

Used to pull 1x or 2x board on wires Used to pull 1x or 2x board on wires up through wall or pour in pea gravel.up through wall or pour in pea gravel.

2121stst century – void space products at century – void space products at bottom of wallsbottom of walls


Applications – Brick VeneerApplications – Brick Veneer


Applications – Stucco,Applications – Stucco,Manufactured/Veneer StoneManufactured/Veneer Stone

Create a rainscreen wall with Create a rainscreen wall with void-space rolled matsvoid-space rolled mats– Roll out like a WRBRoll out like a WRB

– Uniform thickness over wallUniform thickness over wall

– Creates capillary break to separate Creates capillary break to separate cladding from sheathingcladding from sheathing

– Promotes drainage and dryingPromotes drainage and drying


Applications – Stucco,Applications – Stucco,Manufactured/Veneer StoneManufactured/Veneer Stone


ConclusionsConclusions

Walls no longer dry by themselvesWalls no longer dry by themselves

Heightened concern over moisture Heightened concern over moisture liability and changing codesliability and changing codes



Building science agrees that Building science agrees that rainscreen wall is rainscreen wall is bestbest wall system wall system and NAHB recent white paper and NAHB recent white paper recognizes.recognizes.

Learn from brick veneer - create a Learn from brick veneer - create a space between the cladding and the space between the cladding and the WRB/sheathing/framingWRB/sheathing/framing



Advances in technology have Advances in technology have broadened the range of solutions broadened the range of solutions available to you to prevent problems available to you to prevent problems

Upfront cost $1000 to $5000 vs. Upfront cost $1000 to $5000 vs. $75,000 to $300,000+ after the fact$75,000 to $300,000+ after the fact


Thank youThank you

2009 IBS - High Performance Masonry Walls

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Transcript of 2009 IBS - High Performance Masonry Walls