How To Vent An Old Attic

You can also contact your local municipality to check on building code in your area.

How to vent an old attic.

Then set your circular saw to that depth and cut along the chalk lines. Hole through the soffit right between the lines and measure the thickness of the soffit panel probably 1 4 or 3 8 in. It must also circulate. A 30 x 40 ft.

First determine your attic area by multiplying the length by the width. Begin by making sure your existing system works photos 1 and 3 plugging major air leaks into the attic photo 2 and correcting any other of the common causes of poor attic venting. Next bore a 3 4 or 1 in dia. Attic for example has an area of 1 200 sq.

If those steps don t solve the problem add more soffit vents following the techniques we show in photos 4 17. Draw an outline for it on the soffit and cut the hole with a reciprocating saw. Then aim for about 1 sq. Fit the vent in the hole and nail it to the soffit with.

Cut the two parallel lines with a portable circular saw. That said air resistance and interference such as vent grates reduces the area of true ventilation. Hot air exhaust vents located at the peak of the roof allow hot air to escape. Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation.

The building code lets you reduce that by half under some conditions but more roof ventilation is usually better. In of vent opening per 150 sq. If you don t currently have gable vents then it would be a good idea to install this vent. The idea is that wind goes into one gable vent and then pushes the air out of the attic and through the secondary gable vent on the other side of the attic.

For proper ventilation it isn t enough for air to simply get into your attic. Install a soffit vent by working outside the house. In other words the entire vent opening doesn t count as vented space. For this reason the square footage of vent space at the base of the roof and at the peak.