How to make it work for YOU
What is spray foam Building science as it relates to spray foam Different types of spray foam Applications
ISO “A” Side
100% Isocyanate
RESIN “B” Side
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.
Insulation and air barrier in one material Vapour retarder, sometimes Cellular plastic insulation
Spray foam truck arrives on schedule, when promised Two liquid components, mixed under pressure at the tip of a spray gun When mixed, expands 30-100 times in seconds and sets within 30 seconds Excess trimmed and removed
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
Building Science 101 As it relates to Spray foam
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. Hot Side
2 in
1 in
Staple
Fiberglass Screening
Cardboard stapled to stud
Cold side
Crimping at the corners of the stud cavity
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
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
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.
Moisture moves through building assemblies by two mechanisms: Air Leakage
Air leakage may occur anytime there is a difference in air pressure on either sides of material
Vapor Diffusion
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?
Canada Mortgage & Housing Corp – cmhc-schl.gc.ca
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
½ POUND FOAMS
2 POUND FOAMS
Can be generally divided into two types ½ lb foams 2 lb foams
Similarities ▪ Chemical composition ▪ Air sealing characteristics ▪ Thermal barriers ▪ Safety and health during application ▪ Exothermic reaction creates foam ▪ Very technical installation
½ POUND FOAMS
TWO POUND FOAMS
Open cells Contain air Reaction of water in the polyol with the MDI
Closed cell Contain gasses trapped in the closed cell structure Cells created by a chemical blowing agent
½ POUND FOAMS
Trapped air creates thermal resistance R value typically R3.63.8/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.
½ POUND FOAMS
TWO 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)
Considered a vapour barrier at certain thickness Depends on substrate Code officials may require vapour protection for framing
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….
2 LB foam sprayed too thick
Too thick = -elongated cells -weak cells
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
½ POUND FOAM
TWO POUND FOAM
Recycled content +/ Waterblown Carbon dioxide from reaction, GWP = 1
Recycled content +/ Ozone depleting substances (ODS) being phased out New 245 blowing agent is a greenhouse gas, GWP = 950
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
½ POUND FOAM
TWO POUND FOAM
More economical Less enviro impact
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
Where, when, why and how
Windows
Metal Stud Channels Wide stud spaces
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
IMPORTANT: seal to the top plate of the frost wall
this is how it should be done
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”)
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
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
Vapor barrier installed, Caulk, Tape, Foam to air seal
Icynene installed cost
1015
Vapor barrier installed
Subfloor is vapor barrier
Caulk, Tape, Foam to air seal Material:
Labor:
25 300
Material:
N/R
Labor:
N/R
Callback / Dissatisfaction Cost
???????
Callback / Dissatisfaction Cost
N/A
TOTAL COST:
1005
TOTAL COST:
$1015
-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)
Plumbing and ducts tight to subfloor Make sure adequate foam coverage over plumbing runs “tenting” around plumbing with cardboard may be required.
Huge amounts of moisture coming out of new concrete We’re sealing them up wet, should we? Large potential liability for builders
Several thousand pounds of water from freshly placed concrete attempt to dry inwards.
“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
Thank you
Any questions?
