As long as you have fire grade blocking to the prescribed thickness, there is no issue with other foam on top of it.
Where should you not use spray foam insulation?
For areas too close to ceiling light boxes:
You should not use spray foam to insulate areas around recessed ceiling canister lights. If you spray too close to the top of ceiling light boxes, you can trap heat and increase the risk of a fire.
Is 3M fire block foam flammable?
In fact, fireblock foam found in hardware stores is actually flammable and does little to prevent the spread of a fire and smoke. Firestop products must be tested according to ASTM E814 (UL 1479).
Is expanding foam flammable?
Expanding foam is used in DIY to fix and fill holes and gaps. The propellant gas used to dispense the foam (methylene-diphenyl-diisocyanate 4,4) is highly flammable. The gas is emitted from the foam as it expands and dries out.
What does spray foam not stick to?
Quote from Youtube video: Absolutely but when it comes to aluminum. Or galvanized or galvalume. If there is no mechanical adhesion ability if you're just gonna be spraying to a large sheet of aluminum or galvanized.
Do you need a ridge vent with spray foam insulation?
Quote from the video:
Quote from Youtube video: Yes you will need roof vents if you have insulation on the attic. Rafters.
Does spray foam insulation cause moisture problems?
While the benefits of spray foam are multifaceted—it can reduce energy costs, increase a home’s structural integrity, create a moisture barrier and prolong the life of an air conditioning unit—it can also cause problems.
Is fire block spray foam combustible?
DuPont Polyurethane Foam Insulation and Sealants CAUTION: When cured, these products are combustible and will burn if exposed to open flame or sparks from high-energy sources.
Is spray foam heat-resistant?
Like many materials found in a home or building, spray foam can ignite and burn if exposed to a sufficient heat source. Foam insulation should be considered combustible and handled accordingly.
Is fire block foam fire resistant?
3M™ Fire Block Foam FB-Foam is a fireblock and draftstop used to help seal, fill, insulate and bond for non-rated residential and commercial construction. This foam-in-place fireblock is heat-resistant (up to 240°F/115°C) and meets ASTM E 84 (mod) Class 1 for smoke spread and flame development.
Will mice chew through spray foam?
RODENT RESISTANT EXPANDING FOAM
Rodents can also squeeze through gaps and openings in pipes, so you’ll want to seal around those, as well. Filling the cracks and voids with the polyurethane foam acts as a rodent barrier, as mice and other rodents aren’t able to chew through spray foam insulation.
Is expanding foam heat proof?
Fire rated expanding foam can be used as an efficient seal against smoke and gas, providing up to 240 minutes fire rating. As well as being useful due to its excellent filling characteristics, fire rated foam has high thermal properties and provides acoustic insulation.
How thick can spray foam be applied?
The ASTM E84 tests for most spray polyurethane foams limit the maximum installed thickness of foams to 4 inches or less. The ASTM E84 tests for some SPF products limit installations to a maximum of only 2 inches.
Do you need a vapor barrier with spray foam?
A vapour barrier is not necessary with closed-cell foam but with open-cell spray foam such as Icynene®, it is sometimes required. Any air that migrates though a building envelope will carry water vapour. As Icynene® spray foam creates a seamless air-seal, it controls air leakage and the moisture in the air.
Can spray foam rot your roof?
Studies show that open-cell spray foam is risky in colder climates. Indoor moisture diffuses through the foam and comes in contact with the cold roof sheathing. The spray foam traps the moisture against the roof, which results in eventual decay.
Should I insulate the underside of my roof?
roof insulation is no-contest. The floor wins every time. Insulating the floor is standard practice for an unfinished attic space. The exception to this rule takes place when families opt to convert an unfinished attic space into something usable or livable.
Can you spray foam rafters?
Quote from the video:
Quote from Youtube video: Almost. Every time when you're looking at the the attic floor now why is that important well most of time your cost is directly related to how much square footage is being spray foamed.
Should I spray foam my roof?
Spray Foam Attic Rafters
Insulating the attic rafters with spray foam creates a conditioned space where your attic is the same temperature as the rest of your home. This keeps the external weather and moisture outside of the attic space so you don’t have to worry about any moisture problems or air infiltration.
Can you spray foam your roof?
Open-cell spray polyurethane foam or closed-cell spray polyurethane foam (ccSPF) insulation can be sprayed along the underside of the roof sheathing to provide a conditioned and insulated attic space that can be durable and efficient in all climate zones (see Figure 1).
Does spray foam insulation cause wood rot?
It’s a reasonable question to ask, considering that some homes with open-cell spray foam insulation installed on the underside of the OSB roof sheathing have reported moisture problems. There’s also a pretty reasonable answer to will spray foam will rot your roof: No spray foam will not rot your roof.
Does spray foam insulation stop mold?
Spray foam insulation keeps your living space free of moisture and allows you to prevent mold growth!
