Moisture-related problems in your attic can lead to early roof failure as well as health and comfort problems. Sealing your attic, in combination with proper insulation and ventilation, can improve your quality of life and increase the durability and energy efficiency of your home.
As warm air travels upward, it carries moisture along with it. Sources of moisture in the average home can include humidifiers, bathrooms, and laundry rooms.
An improperly sealed attic will simply allow upward traveling moisture to enter into it. Once the moisture is inside of your attic it will condense on the cooler surfaces. This condensation can cause a variety of moisture-related problems.
Poor home renovation workmanship can often make problems worse by allowing more moisture into the attic. Examples include non-vented exhaust fans, unsealed attic floors, recessed lighting fixtures and other humidity increasing improvements.
Attic condensation, buckled shingles, mold and mildew occur when attics get wet in the winter from warm air rising through the ceiling and condensing on cooler surfaces. More than often the cooler surface is wood and when it gets wet, it expands. In the spring, the attic gets warm and the wood dries and contracts. This constant process loosens nails and causes shingles to buckle.
Ice damming may also occur when warm air rises into the attic, or if ducts in the attic are poorly insulated and/or not sealed. Heat from these sources causes snow on the roof to thaw. As the melted snow reaches the colder soffit area, it may refreeze, creating a dam which causes the water underneath to back up under the shingles.
Mold and mildew leads to rotten wood and ultimate roof failure. More importantly however, it can cause serious health problems for pregnant women, infants, the elderly and those with allergies or respiratory diseases such as asthma or weakened immune systems.
There is a common misconception that moisture can be eliminated by adding more ventilation in the attic. This is simply not true. An imbalanced ventilation system can pull more moisture into the attic and make conditions worse. If you want to keep your attic dry, then you need to stop the source of the moisture in the first place — your home interior.
The goal is to stop warm moist air from getting into the attic and keeping the heat that you pay for inside your house where it belongs. While this may seem to be a simple enough task in theory, you might want to hire a reliable contractor with experience in the sealing & insulation of attics.
Areas that a contractor will seal/insulate include attic hatches, HVAC ducts, chimneys, top plates, penetrations from wiring conduits & plumbing, dropped ceilings, bulkheads, electrical fixtures such as lighting and ceiling fans, penetrations from exhaust fans & range hoods, knee wall areas, party walls and skylights. This is not an extensive list, but it covers a majority of your target areas.
No matter how you proceed with the project, the benefits far outweigh the time and money put into it; extended roof life, prevention of mold growth, improved comfort and lower energy bills.