Attic Humidity Spray Foam

Compared to traditional insulation whether fiberglass or cellulose spray foam has the potential to provide better performance via its air sealing properties high r values per inch of thickness and in the case of closed cell spray foam ability to repel moisture.

Attic humidity spray foam.

Lstiburek calls this the ping pong effect. With it the orientation and type of insulation applied to the top of the building enclosure has changed from the traditional way and so temperature and moisture conditions experienced by various assembly elements will be impacted. Using icynene spray foam as your attic insulation will turn your attic into a conditioned space. Because water vapor is lighter than dry air mostly nitrogen and oxygen that layer of air can move upward in the attic.

The result is higher humidity at the ridge than at the floor. When the water vapor exits the spray foam it increases the relative humidity of the layer of air near the foam. Check for negative pressure. Oh and when you put it in your attic spray foam insulates the attic itself.

By doing so you bring the attic inside the building enclosure. Jason advani has insulated his attic with spray polyurethane foam and while his heating bills have dropped high humidity remains a problem. I think two things may have happened the day they sprayed the foam the attic conditions were probably pretty similar to the exterior and probably even hotter. Let s say hypothetically exterior was 90 degrees and 70 humidity inside the attic was probably 110 degrees with the same amount of moisture in the air as the exterior.

One of those problems is moving the building enclosure from the drywall ceiling of a home to the roofline. To some unvented attic construction using spray foam insulation is a fairly new approach in home building. As with pretty much all home improvement projects your contractor might. One of the most common reasons to put spray foam on the roofline is to avoid having to air seal the attic floor because the attic is connected with the air in the house and indoor air is more humid than outdoor air which can cause moisture problems.

This will allow for optimal operation of your hvac equipment as well as aid in early detection of situations such as roof leaks and wind driven moisture intrusion. Make sure your attic is properly sealed. If mechanical systems in your home create a negative pressure environment you could. How to manage humidity in your spray foamed attic 1.

It will also help keep any duct leaks within the conditioned space of your attic.