How To Vent An Old Attic

In other words the entire vent opening doesn t count as vented space.

How to vent an old attic.

If you don t currently have gable vents then it would be a good idea to install this vent. If those steps don t solve the problem add more soffit vents following the techniques we show in photos 4 17. 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. A 30 x 40 ft.

It must also circulate. For this reason the square footage of vent space at the base of the roof and at the peak. Cut the two parallel lines with a portable circular saw. For proper ventilation it isn t enough for air to simply get into your attic.

Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. The building code lets you reduce that by half under some conditions but more roof ventilation is usually better. 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. Hole through the soffit right between the lines and measure the thickness of the soffit panel probably 1 4 or 3 8 in.

That said air resistance and interference such as vent grates reduces the area of true ventilation. Fit the vent in the hole and nail it to the soffit with. Install a soffit vent by working outside the house. Then set your circular saw to that depth and cut along the chalk lines.

Most building codes require a ratio of 1 150 ventilation space to attic floor space. 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. Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic. In of vent opening per 150 sq.

Next bore a 3 4 or 1 in dia. Hot air exhaust vents located at the peak of the roof allow hot air to escape. First determine your attic area by multiplying the length by the width. Then aim for about 1 sq.