Attic Humidity Spray Foam

Oh and when you put it in your attic spray foam insulates the attic itself.

Attic humidity spray foam. Lstiburek calls this the ping pong effect. To some unvented attic construction using spray foam insulation is a fairly new approach in home building. 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. 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.

Using icynene spray foam as your attic insulation will turn your attic into a conditioned space. 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. Spray foam recommendations unvented attic no vents so no gas except direct vent sealed combustion only supply a c in warm humid climate low perm underlayment light color shingles metal or tile closed cell in cold climates ok in any open cell in rainy hot climate vented to unvented attic conversion existing homes all the above. One of those problems is moving the building enclosure from the drywall ceiling of a home to the roofline.

The result is higher humidity at the ridge than at the floor. Jason advani has insulated his attic with spray polyurethane foam and while his heating bills have dropped high humidity remains a problem. When the water vapor exits the spray foam it increases the relative humidity of the layer of air near the foam. By doing so you bring the attic inside the building enclosure.

How to manage humidity in your spray foamed attic 1. Because water vapor is lighter than dry air mostly nitrogen and oxygen that layer of air can move upward in the attic. 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. Make sure your attic is properly sealed.

It will also help keep any duct leaks within the conditioned space of your attic. Jason advani jason advani thought he was on the right track when he insulated the bottom of the roof deck in his walk up attic with closed cell spray foam. Check for negative pressure. 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.

If mechanical systems in your home create a negative pressure environment you could.