If a vaporretarder is not present in the ceiling to slow migration of moisture from thehome s interior into the attic attics require 1 square foot of free vent areafor each 150 square feet of attic area.
Old house no attic ventilation.
This creates a natural air flow by drawing in the air from outside pushing it up and out through the vent at the top of the house.
Unless your roofing system has insulation on the roofing deck and is designed without ventilation your furnace should not be heating your attic.
Get the latest this old house news updates and special offers every week direct to your inbox.
Though it s against building code to vent any kind of exhaust to an attic space many home builders have gotten away with this shortcut.
Poor attic ventilation can also be a contributing factor in the formation of ice dams in winter.
This is called passive ventilation.
Poor insulation is usually the culprit although if you enter the attic on sunny winter day your attic space can be warmed by the sun more than your furnace.
If the attic is insulated with fiberglass batts just pull back any that are blocking the flow of air.
There s no getting around it.
Old house no attic ventilation.
Passive active options any unconditioned attic requires ventilation.
The total venting space should equal 1 150 of the floor space.
When the attic becomes part of the home to be heated and cooled open wall gable vents and roof vents are no longer feasible but the underside of the roof the sheathing and rafters can still get.
Your roof vents may not look anything like the ones shown in this article.
Look at your eaves and roof.
Your roof may have a ridge vent which is a low profile continuous roof air vent running along the peak of the roof.
The soffit vents are now installed but you still need to make sure there s no insulation blocking the new vents.
If you don t see any attic vents on the roof or in the eaves you need to add some.
Adequate natural ventilation is important in the attics of homes.
A passive ventilation system should have air inlets at the base of the roof usually in the soffits and outlets in the peak or gables.
If there s blown in insulation like ours rake back the fluffy stuff with a 3 or 4 ft long 1 x 6 or use a garden rake or hoe.
The most common way to add ventilation to an attic is by installing air intakes in the soffits and putting an outlet at the gable of the house.
If your house is in a cold climate keeping it warm in winter is expensive.
Moisture problems attic ventilation old house.