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.

Does spray foam insulation cause mold?

Foam building insulation, in both spray foam and foam board products, is resistant to mold growth but as we will explain here it is not absolutely mold-roof, and on occasion we do find mold growth on the surface of even closed-cell foam, in open-celled foam (rare), and on th surface of EPS and other foam insulating …

Do you need an air gap for spray foam insulation?

Spray Foam does not require an air-gap because it is spray-applied to the membrane and becomes an extension of the substrate with no opportunity for moisture to become trapped.

Should you vent a flat roof?

It’s almost always needed, except for houses that already have warm flat roofs. As for cold flat roofs, which are more common, they need this type of ventilation because they collect higher amounts of condensation during the winter.

What is the best way to vent a roof?

For the best results, place roof ventilation near the roof’s peak and soffit vents in the eaves. Air flows in through the soffit vents and out through the roof vents. Vents come in various styles. We chose rectangular, hooded roofing vents and rectangular soffit vents because they’re easy to install.

Is foam insulation air tight?

The sealing, continuity of application and impermeability that the foam provides offers air tightness and no additional vapour barrier is needed for most applications, nor other accessories such as adhesives, tapes, separators or sealants that guarantee air tightness of the enclosure.

How is a flat roof vented?

To take care of flat roof ventilation, a thermal insulation layer is first positioned beneath the roof. This ensures that the hot air has a chance to move and finally escape through the air ducts. However, another layer called the vapor control layer needs to be installed.

Do I need to ventilate my attic with spray foam insulation?

Ventilation is not needed in attics with spray foam insulation because sealed attics that have spray foam applied on the underside of the roof sheathing (the attic’s ceiling) should be airtight, ie they are thermally and physically closed off from the outside world.

Should the flat roof be vented or insulated?

The current best practice is to fully insulate the rafter space and NOT vent the flat roof. To document current best practices in this regard we have three reference points, with explanations and links below: A German building science trade article: Ventilated or not?

Can I use spray foam insulation on my roof?

Basically, code prohibits venting when you spray foam on the underside of the roof. There are minimum foam R-values if you use spray or rigid foam in combination with traditional air-permeable insulation (like fiberglass or cellulose), but they don’t apply in your case.

Will spray foam seal a ridge vent?

To add to what Brian said, closed cell spray foam (ccSPF), applied directly to the underside of the roof sheathing, would seal a ridge vent shut. There is no need for a ridge vent in this application since the ccSPF seals the roof.