Ice dams are preventable. Seal gaps and holes in the ceiling to block heat loss into the attic.
Mansfield, MA (PRWEB) February 22, 2015
In a well designed and constructed home, the attic has its own dry and cool environment, quite separate from the living space. If the attic is not isolated from the rest of the house with proper air sealing and insulation, it can become warm and moist.
Without adequate air sealing, heat collects in the attic and warms the roof, except at the eaves. Warm attics melt the bottom layer of snow on the roof, causing water to run down to the gutter where it refreezes. This is the beginning of an ice dam.
Over time, the ice dam can grow and cause numerous problems. Dams can tear off gutters, loosen shingles, and cause water to back up and pour into the house. When that happens, the results aren't pretty: peeling paint, warped floors, stained and sagging ceilings. Not to mention soggy insulation in the attic, which loses R-value and becomes a magnet for mold and mildew.
HOW DOES HEAT AND MOISTURE GET INTO THE ATTIC?
There are several sources, both exterior and interior. If the roof is old and leaking, obviously that is an exterior moisture source. But lets talk about interior sources that are often overlooked, but are not too difficult to correct.
Interior sources include air leaks from the house into the attic. Moisture is carried by air movement from the warm home into the cold attic, where the moisture in the air condenses and wets cold surfaces, such as the roof sheathing and rafters. Over time, chronic moisture causes mold and mildew.
PLUG THE AIR LEAKS TO STOP THE MOISTURE.
The largest "holes" leading directly from the house to the attic are the attic access and the whole house fan.
When the attic access is a fold-down stairway, it is a difficult to control moisture and heat loss. The Battic Door R-50 Attic Stair Cover is a low-cost, easy-to-install solution to this common problem.
When the attic access is an access hatch, control moisture and heat loss with a Battic Door E-Z Hatch R-50 attic access door. It is a low-cost, easy-to-install solution for new and existing homes and provides an air tight, high performance, attic access door.
When a whole house fan is installed in the home, moisture and heat loss flow right through the louvers and into the attic. The Battic Door Whole House Fan Shutter Seal is a low-cost, easy-to-install solutions to this common problem. Easy to install, trim to fit.
Other air sealing ideas include:
1. Ventilate Eaves And Ridge. A ridge vent paired with continuous soffit vents circulates cold air under the entire roof. Both ridge and soffit vents should have the same size openings and provide at least 1 square foot of opening for every 300 square feet of attic floor. Place baffles at the eaves to maintain a clear path for the airflow from the soffit vents.
2. Exhaust to the Outside. Make sure that the ducts connected to the kitchen, bathroom, and dryer vents all lead outdoors through either the roof or walls, but never through the soffit.
3. Add Insulation. More insulation on the attic floor keeps the heat where it belongs. To find how much insulation the attic needs, check with the local building department.
4. Install Sealed Can Lights. Old-style recessed lights give off great plumes of heat and can't be insulated without creating a fire hazard. Replace them with sealed "IC" fixtures, which can be covered with insulation.
5. Flash Around Chimneys. Bridge the gap between chimney and house framing with L-shaped steel flashing held in place with unbroken beads of a fire-stop sealant. Using canned spray foam or insulation isn't fire safe.
6. Seal and Insulate Ducts. Spread fiber-reinforced mastic on the joints of HVAC ducts and exhaust ducts. Cover them entirely with R-5 or R-6 foil-faced fiberglass.
7. Caulk Penetrations. Seal around electrical cables and vent pipes with a fire-stop sealant. Also, look for any spots where light shines up from below or the insulation is stained black by the dirt from passing air.
For more tips and ideas to prevent energy loss, visit the Battic Door Energy website at http://www.batticdoor.com.
ABOUT THE AUTHOR - Mark D. Tyrol is a Professional Engineer specializing in cause and origin of construction defects. He developed several residential energy conservation products including an attic stair cover and an attic access door. Battic Door Energy Conservation is the US distributor of the fireplace plug. To learn more visit http://www.batticdoor.com.