The Inside Story on Ventilation
When you read about ventilation with regard to your home’s exterior, it can be confusing. But it’s really quite simple: ventilation is simply a means to get air into – and out of – your home, specifically the attic. You’ve no doubt heard that poor ventilation leads to energy loss. What you may not know is that poor ventilation in your attic can cause even worse problems, like wood rot, mildew, peeling exterior paint rusted nails and screws and even roof problems. The good news is that most of your ventilation problems can be easily and inexpensively addressed. And doing so during an exterior remodeling project is the best time to address it.
Attic Ventilation Basics
Ventilation is a system of low vents, like soffit vents, and high vents, like ridge and gable vents. To achieve proper ventilation, outside air should enter the attic low at the attic perimeter and exit high near the attic ridge. You must provide an air gap at the overhang (soffit) and eaves to control the accumulation of moisture. Continuous soffit vents in combination with other outlets (ridge vents, mushroom cap vents, and upper gable vents) will produce the maximum amount of attic intake ventilation. If your roof has minimal or non-existent overhangs, you may not be able to use soffit vents. Consider installing low gable vents located near the attic ceiling but above the top of the level of the attic ceiling insulation. The only way to know how much ventilation is appropriate for your home is to talk to your builder or remodeler and review your local building codes. Most builders and contractors are familiar with local building codes, but you may want to look them up on your own to make sure the size, type, and placement of your vents are compliant.