How To Vent An Old Attic

Draw an outline for it on the soffit and cut the hole with a reciprocating saw.

How to vent an old attic.

In of vent opening per 150 sq. 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. Cut the two parallel lines with a portable circular saw. A 30 x 40 ft.

If you don t currently have gable vents then it would be a good idea to install this vent. Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic. You can also contact your local municipality to check on building code in your area. If those steps don t solve the problem add more soffit vents following the techniques we show in photos 4 17.

For this reason the square footage of vent space at the base of the roof and at the peak. Hole through the soffit right between the lines and measure the thickness of the soffit panel probably 1 4 or 3 8 in. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Most building codes require a ratio of 1 150 ventilation space to attic floor space.

Next bore a 3 4 or 1 in dia. That said air resistance and interference such as vent grates reduces the area of true ventilation. Then aim for about 1 sq. In other words the entire vent opening doesn t count as vented space.

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. Attic for example has an area of 1 200 sq. Then set your circular saw to that depth and cut along the chalk lines.

It must also circulate. Fit the vent in the hole and nail it to the soffit with. For proper ventilation it isn t enough for air to simply get into your attic. The building code lets you reduce that by half under some conditions but more roof ventilation is usually better.