Old House Attic Ventilation

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

Old house attic ventilation.

Air sealing and insulation. That said air resistance and interference such as vent grates reduces the area of true ventilation. If this air lingers it can condense on the underside of the roof sheathing and rot it. Unless an older house has undergone an energy upgrade it s certain to have too much air leakage and too little insulation.

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. A hot ceiling tells you that the attic is acting like a solar oven raising your cooling bills and cooking the shingles. Warm air that escapes rooms below gets trapped in the attic. Nowhere is this more common than in the attic.

Intake vents located at the lowest part of the roof under the eaves allow cool. Touch your ceiling on a warm sunny day. But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates. Attics that are already insulated will need more elbow grease.

For instance attic ventilation is used widely in cold climates to evacuate the warm moist air that escapes from the living space below. Plan to pull up the flooring and layer new insulation on top of the old. Snow melts and the water refreezes on the cold eaves creating ice dams. 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.

If the attic is insulated with fiberglass batts just pull back any that are blocking the flow of air. Because the simplest and cheapest way to insulate an attic is to add material to the floor. It may seem incongruous to allow cold air into your attic in the middle of winter but attic venting is an important climatic control that protects your house from moisture rot and mold. In the summer vents in the attic keep the house nice and cool.

Warm air can also leave through your attic ventilation. Thick ridges of ice on your eaves in winter are a sign of poor attic ventilation. Attic ventilation adequate natural ventilation is important in the attics of homes. The fan is typically mounted behind a gable end vent but other types are available that exhaust hot air through a roof vent.