To prevent air leakage it is best to seal the building envelope during construction prior to installation of the drywall.
Reasons to seal an attic.
Add weatherstripping around the perimeter and a sweep to the door of a walk up attic.
Use a zippered insulated tent to keep the enclosure draft free attic tent at 7 attic cover insulator 120.
Attic hatch or door.
If it is sealed the blower door will not fluctuate.
Air sealing the building envelope is one of the most critical features of an energy efficient home.
Testing pretty well and sealed is like pregnancy.
Here are three reasons to upgrade your attic with spray foam insulation to add r value and seal air leaks.
If you leave the insulation in the attic floor after insulating the roofline the attic will be cooler in winter than if you remove the insulation.
Bath fan ducted into attic this is one of the main reasons that energy efficiency experts tell you to air seal the attic where the insulation will be installed and ensure bath fans are properly vented before insulating.
The first step of air sealing is testing the attic to identify where the air leaks are.
Air naturally moves upward through your house.
The result will be a much more efficient and comfortable home because your hvac system won t need to run as long to get the house to the temperature you want.
For this reason i break the seal on just about every home i inspect but i never do this without permission from the buyer.
For whatever reason some homeowners make accessing the attic more difficult than it ought to be.
Proper attic insulation combined with air sealing prevents air that has already been heated or cooled from escaping your home.
Pull down stair or ladder.
The most common method which probably isn t deliberate is covering it with the same ceiling texture that many other homeowners can t wait to get rid of.
It either is or it isn t.
But whether or not the attic is sealed you still need to access it.
This makes the attic colder and a colder attic with moisture leaking from the house can result in condensation mold and wood rot.
Affix rigid foam insulation to the attic side of the hatch or door.
Hence my thoughts on sealing off the attic from the rest of the home and not venting it.
Once we know we use an expanding foam to seal the areas and prevent air transfer.
Once covered many air leakage paths will be more difficult and costly to access and properly seal.
Thus the air in the attic is connected with the air in the house.
The easy way to check an attic seal is to start the blower door with the attic access closed then open it.
There is no in between.
I can t really find a compelling reason to spend the money to have a conditioned or semi conditioned non vented attic since i won t have mechanical equipment and ductwork in the attic and i will not be using it for storage.