Hello,
I recently inspected a home that was built in 2012, the home attic space is separate from the garage. The garage has ventilation available but what I noticed is that the home area does not have any under eave soffit ventilation or ridge ventilation. With spray foam insulation does anyone know ho much ventilation is required? Is this considered an issue because not enough ventilation is present?
This might help you Luis
http://www.buildingscience.com/documents/digests/bsd-149-unvented-roof-assemblies-for-all-climates
Its a foamed shut system, there is no ventilation required. The principal is your heat and cooling equilibrate in the attic which isn’t allowing air in or out or radiant energy thru the decking. The foam acts as a radiant barrier and insulation all in one. Its a 180 degree turn on the old idea of venting attics. If you’ve ever been up in one of these in the dead of summer, they’re generally 82 degrees or less. Heating and cooling costs go way down.
This is very helpfull gentlemen. Thank you both for your insight and help.
Luis I don’t know if you are a new inspector or new to Nachi but did you observe the vertical supports on the left. Not the same color as the rest of the 2x’s… looks like possible mold or fire damage.
The problem with the closed system is if there are any leaks or exhaust leaks from a vent fan …open invitation for organic growth…just sayin!
Looks like black HVAC support webbing to me.
Dom.
Look to the right of that
I did.
He mentioned “not the same color”, so I think he’s referring to the items on the left, not the truss in the center.
Dom.
