How to make it work for YOU

Transcription

1 How to make it work for YOU

2 What is spray foam Building science as it relates to spray foam Different types of spray foam Applications

3 ISO A Side RESIN B Side 100% Isocyanate Polyols Surfactants Blowing Agents Flame Retardents Catalysts Etc. All foams are NOT the same. The material selections on the B side make foam systems very different.

4 Insulation and air barrier in one material Vapour retarder, sometimes Cellular plastic insulation

5 Spray foam truck arrives on schedule, when promised Two liquid components, mixed under pressure at the tip of a spray gun When mixed, expands times in seconds and sets within 30 seconds Excess trimmed and removed

6 1) Problem solver Spray and go away Reduce risk, liability and warranty issues 2) Build better buildings -more energy efficient -better indoor air quality -consumers are demanding it

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8 Building Science 101 As it relates to Spray foam

9 1 in A Canadian government study showed that crimping batt insulation (compressing the insulation at the corners) averaging 6% of the cross section of the stud space causes a 20% 35% drop in thermal resistance of the wall. 2 in Hot Side Staple Fiberglass Screening Cardboard stapled to stud Cold side Crimping at the corners of the stud cavity

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11 Most building envelope problems are a result of failed air barriers Moisture travels as airborne water vapour until it hits a condensing plane such as the exterior sheathing in a wall assembly or rim joist With foam, the air barrier is contiguous throughout the wall assembly

12 Be impermeable to air movement Be continuous-seal the entire building Be durable able to withstand changing pressures (wind) Be buildable-easy to install and maintain

13 The 4 qualifications required for air barriers are extremely rigid: Any material or system that fails in any of these is NOT an effective air barrier. Meeting all 4 objectives is extremely difficult with conventional materials and often impossible in modern buildings: Industry concern: that common air barriers are often the victim of subtrades that operate after the air barrier is installed.

14 Moisture moves through building assemblies by two mechanisms: Air Leakage Vapor Diffusion Air leakage may occur anytime there is a difference in air pressure on either sides of material Vapor has a natural tendency to move from areas of high concentration to areas of low concentration. Generally from warm to cold Which is the more damaging mechanism?

15 Canada Mortgage & Housing Corp cmhc-schl.gc.ca

16 AIR LEAKAGE is your biggest problem -not inadequate insulation -not vapour barrier Ineffective or compromised air barriers create most problems associated with building envelopes in our climate

17 ½ POUND FOAMS 2 POUND FOAMS

18 Can be generally divided into two types ½ lb foams 2 lb foams

19 Similarities Chemical composition Air sealing characteristics Thermal barriers Safety and health during application Exothermic reaction creates foam Very technical installation

20 ½ POUND FOAMS Open cells Contain air Reaction of water in the polyol with the MDI TWO POUND FOAMS Closed cell Contain gasses trapped in the closed cell structure Cells created by a chemical blowing agent

21 ½ POUND FOAMS Trapped air creates thermal resistance R value typically R /inch TWO POUND FOAMS Trapped gasses create thermal resistance Initial R Value is R7.5/inch aged R Value - declines over time to R6/inch due to cell gasses near surface escaping.

22 ½ POUND FOAMS Not a vapour barrier Considered a breathable foam system Has drying potential requires separate vapour barrier, when required Other building components may act as vapour barrier (ie: OSB floor in bonus rooms) TWO POUND FOAMS Considered a vapour barrier at certain thickness Depends on substrate Code officials may require vapour protection for framing

23 ½ POUND FOAMS Typically sprayed in one pass at any thickness Easily trimmed with handsaw TWO POUND FOAMS Usually not trimmed, requires special scarfing tool Adhesion to substrate critical Typically sprayed max 2 thick per pass Must let the heat dissipate from foam before next pass, or else.

24 2 LB foam sprayed too thick Too thick = -elongated cells -weak cells

25 ½ POUND FOAMS Liquid water can be forced in under pressure. Typically drains through or dries Absorbtion varies by Mfr. from 4% to 47% Check the Data sheet or CCMC report TWO POUND FOAMS Resists water penetration Absorbtion generally less than 4% Will provide additional rain/moisture control on outside of buildings

26 ½ POUND FOAM Recycled content +/- Waterblown Carbon dioxide from reaction, GWP = 1 TWO POUND FOAM Recycled content +/- Ozone depleting substances (ODS) being phased out New 245 blowing agent is a greenhouse gas, GWP = 950

27 When you have a limited cavity size and need the extra R Value When you have compressive strength requirements exterior basements Unidirectional and extreme vapour drive Cold storage, freezers

28 ½ POUND FOAM More economical Less enviro impact TWO POUND FOAM Vapour barrier Higher R per inch Use the more affordable ½ pound foam unless there are specific reasons to use 2 pound foam Because if foam is more economical, people will be more inclined to use it

29 Where, when, why and how

30 Windows Metal Stud Channels Wide stud spaces

31 Major source of air infiltration Extremely difficult to air seal with poly and sealant around penetrations What are the long term implications of the engineered joists getting wet? This is what is holding your house up

32 IMPORTANT: seal to the top plate of the frost wall

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34 this is how it should be done

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36 Eliminate the need for hot boxes No need to heat space below floor No drop framing Virtually a trade off economically for a much superior system (compared to a hot box )

37 Floor temp will typically be within 2 deg. of room temp Contact with heating ducts is a code issue but specific testing can be done by mfr. to satisfy code officials. This testing is specific to each manufacturer s product

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42 Hot Box Garage Ceiling (Rm 12 x 26 ) 312 sq ft Spray foam Garage Ceiling (12 x 26 ) 312 sq ft Supply & Install hot air supply ductwork 50 Install hot air supply ductwork N/R Supply & Install return air ductwork 50 Included Install return air ductwork N/R -to create pressurized plenum under floor Drop framing to create conditioned space in the garage ceiling Drop framing to create conditioned space in the garage ceiling 2 x6, misc osb Material: 100 Material: N/R Labor: 150 Labor N/R Fiberglass - material cost 330 Icynene installed cost 1015 Vapor barrier installed, Caulk, Tape, Foam to air seal Vapor barrier installed Subfloor is vapor barrier Caulk, Tape, Foam to air seal Material: 25 Material: N/R Labor: 300 Labor: N/R Callback / Dissatisfaction Cost??????? Callback / Dissatisfaction Cost N/A TOTAL COST: 1005 TOTAL COST: $1015

43 -no frost blooms on garage walls from conditioned air being pushed outside the building envelope -no condensation dripping from screws on garage ceiling -no worries about carbon monoxide getting into living space -no cold floor/cold room complaints -no frozen pipes(make sure adequate foam coverage)

44 Plumbing and ducts tight to subfloor Make sure adequate foam coverage over plumbing runs tenting around plumbing with cardboard may be required.

45 Huge amounts of moisture coming out of new concrete We re sealing them up wet, should we? Large potential liability for builders

46 Several thousand pounds of water from freshly placed concrete attempt to dry inwards.

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52 Rigid foam systems or spray-applied foams are recommended for this purpose, because they allow drying, are not sensitive to moisture damage, and do not support mold growth essential characteristics for all materials which contact the basement wall and basement floor slab. BSD-103 Understanding basements, Building Science Corporation

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58 Thank you Any questions?