The unvented attic space is considered the most effective and up to date building practice particularly by the spray foam industry.
Spray foam attic dump zone.
It s quick and easy to do.
Using spray foam insulation in an attic is a popular energy saving project.
And the benefits range from much lower utility bills to fewer pests to reduced sound transfer.
While this type of attic system is the most commonly used system in the u s it is not the ideal system when it comes to energy efficiency indoor comfort and.
No indications of moisture damage were observed.
Because basically now that attic is a conditioned space.
Attics with spray foam insulation are so cool.
I have a spray foamed attic.
Normally in occupied areas all spray foam must be covered by a 15 minute thermal barrier such as thick drywall per code requirements in irc section 316 4 and ibc section 2603 4.
It s just a pathway.
Nothing unusual about that.
Spray foam estimated r 30 was applied at the roof structure of an attic in a home located in climate zone 6.
Nope you absolutely do not need to ventilate a spray foam house and here s why.
It s the wood decking that stores the moisture though.
We mean that literally by the way.
Earlier this year i got a question about a home that had spray foam insulation in the attic.
The role of open cell spray foam.
Sealing the top of the house keeps the air you paid to heat and cool inside your home.
Open cell spray foam insulation doesn t store the moisture.
Although spray foam insulation has been in use since the 1940s primarily for aircraft for the past 30 years continual product innovation has seen the increased adoption of spray foam insulation in residential and commercial construction.
Intumescent coatings are not always needed to coat spray foam in the attic in order to meet code thermal barrier requirements.
It has a relatively high vapor permeance 3 perms at a thickness of 6 allowing water vapor to migrate to the roof decking at night and back into the attic air in the daytime.
A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits but then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents.
When you insulate the top of your attic with spray foam you re bringing your attic into your home s envelope as a result you can reduce the temperature in your attic by a lot anywhere from 120 degrees to around 95 during peak summer.
All sheathing locations that were measured were less than 18 mc.
