Keep the attic cool to prevent ice dams

March snowstorms are common in Carson City, and when they strike, they usually leave lots of snow on rooftops.

And what does that mean to the homeowner? Well, it's a reminder to check the insulation in the attic to avoid heat loss through the soffits and vents. It should also be a reminder to think about ice dams.

Ice dams form when heat from the attic melts the snow on the roof. The melting water then runs down to the eaves, where, coming in contact with the cold there, freezes into a dam. More water runs down and backs up behind it. Where does that water go?

Back under the shingles, lifting them up and allowing water to seep in.

Not good.

What's the answer, other than rigging electric heating wire around the roof at the eaves? Keep the attic cold. That way, the snow will melt slowly, ice dams won't form, and you don't have to displace those heating wires.

Ideally, the underside of the roof should not exceed 30 degrees Fahrenheit, say the experts. To keep the attic at that, the homeowner needs to keep the hot air from below out of the attic. That means gaps that allow the hot air to get to the attic need to be sealed.

Of course, insulation directly on the top side of the ceiling is a must, and, within reason, the more the better. Old insulation tends to settle down and lose its effectiveness, so a check of the current insulation might be in order.

Adding insulation isn't difficult; almost any moderate do-it-yourselfer can handle it. You need an assistant to hand the batts up to you and a pole to slide the insulation into place. Just remember to step only on the beams or rafters; otherwise, you could land in the living room.

Plugging the gaps

Most homes have a folding stairwell or a trapdoor in a closet leading to the attic. These are sometimes ignored when the folding stairway is installed - big mistake.

From the attic, pull back the insulation over the trapdoor. Seal the edges with spray-foam insulation. Then build a a cover with construction cement that fits over the folding stairway of polystyrene insulation. Make sure the cover fits snugly over the stairs.

Then seal the pipe, duct, cable and vents with foam insulation. Careful, though - don't spray the foam around recessed lighting fixtures not rated for safe insulation contact. In the long run, you might want to replace any fixtures not so rated with safe-rated fixtures. This avoids the fire hazard.

Knee walls in finished attics span the rafters and the floor. The space is often used for storage. Insulate the back of these doors by gluing rigid polystyrene insulation panels with builders' cement.

Insulation is often put between rafters in the roof. Check for sagging insulation. If it is drooping, put it back in place with duct tape stapled to the roof rafters. Better yet, drywall can hold the insulation in place, seals drafts, and improves fire resistance in the roof.

n Contact Sam Bauman at sbauman@nevadaappeal.com or 881-1236.