Spray Foam Insulation Attic Ventilation
However all homes need some ventilation.
Spray foam insulation attic ventilation. But then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents. Spray foam kits are quicker and easier to use plus you get a seamless air barrier and high r value in just 1 inch. Otherwise contaminants can accumulate and linger in your indoor air. Spray foam is applied directly where it s needed ensuring that any ventilation vents are left untouched.
But spray foam insulation used at the underside of the roof deck would need to be covered by a thermal barrier and intumescent coatings are commonly used. This alternative to traditional building insulation fiberglass can be applied into wall cavities holes concrete slabs and even onto roof tiles and. Nothing unusual about that. Spray foam is eco friendly non toxic and thermally efficient.
One of the biggest benefits of using spray foam is to get greater airtightness. The point i m making here is that a sealed attic should be well all sealed up. Spray polyurethane foam is a chemical product that is created by two materials isocyanate and polyol resin that will react with each other when they are mixed and will expand up to 30 to 60 times its liquid volume as it is sprayed in place. Generally speaking that s a good thing.
That means you get rid of all attic ventilation whether it s passive ridge gable soffit vents or active fans. Becoming more affordable significant long term energy savings sealing restricts air movement through the building envelope. Spray foam provides an air seal. Spray foam from home logic is an excellent insulation type to choose for the attic.
A well sealed home does a better job keeping conditioned air inside. As such it would seem venting the attic would increase the potential for condensation. However the opposite is true when the attic floor is air sealed and insulated. Air sealing also reduces the natural ventilation rate or air leakage rate further reducing heating and cooling loads.
Spray foam insulation may prevent your home from getting enough ventilation. Properly designed ventilation can reduce airborne levels of aerosols mists and vapors generated during spray application and can help protect spf applicators helpers and others who may be working in adjacent areas. A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits. A case of incompatibility.
Even when outside air is hot and humid if the attic space is air sealed from the interior it is much hotter than outside air. The spray foam expands on contact filling up the space where it begins working immediately. The movement of air into indirect conditioning of an unvented attic is a slow gradual process that will not be noticeable by occupants and typically will not put any strain on the hvac system. Spray foam insulation has been increasing in popularity over the last several years due to.