People seldom think about it, but the attic access opening can account for a significant loss of heat from your home during winter.

This loss is a combination of heat flow through the uninsulated cover and warm air leakage where it rests on the molding. The attic access opening is usually located in a hallway or closet, so air leakage into and out of it is not readily noticeable.

During summer, heat from the roof radiates down into your home through the uninsulated access cover. With adequate attic ventilation, during the summer, a slightly negative pressure exists inside the attic area. If you air-condition, a leaky access cover draws cool air from your house and forces the air conditioner to run longer. If you do not air-condition, the air leakage actually can help to ventilate your home naturally by effectively creating a solar chimney.

When I moved into my home, the attic cover was just a 20×22-inch piece of thin plywood resting on uneven wood moulding around the access opening. To correct this gap, I stuck thick adhesive-backed closed-cell foam weather stripping on the top of the moulding. I cut each of the four lengths slightly longer than each side of the moulding because it may shrink over time. Also, it may have been stretched somewhat when it was pulled off the roll.

Next I nailed a layer of old drywall over the plywood to give it enough weight so the cover would compress the weather stripping for a tighter seal. Drywall is better to use than just a piece of lumber because it creates a fire resistant barrier in case a fire would start in the attic. House fires from a creosote-filled chimney can often start in the attic, near where the chimney passes through it.

I glued several layers of rigid foam insulation on top of the drywall to provide an insulation level as high as the rest of the attic floor. Finally, I covered the rigid foam insulation with a layer of aluminum foil. The foil helps block the radiant heat transfer from the hot roof during summer so less heat gets through to my bedroom.

The above method works well for a small access opening, but not necessarily for a large one. It can be dangerous trying to lift a large heavy cover while you are standing on top of a ladder. For this, or if you have a standard large access opening with pull-down folding stairs or a ladder, install a deep cover that fits over the stairs and still seals against the floor. The bottom cover of typical folding stairs may not seal well against the ceiling nor does it provide much insulation value.

There are several products designed for large access openings or ones with folding stairs. For any of these, install plywood on the attic floor around the opening. This provides a flat surface so a cover seals well and a safe place to step when you enter the attic.

Battic Door™ offers a reasonably priced simple design which is basically a very strong cardboard box sized to fit over the opening and the stairs. You attach your own fiberglass batt insulation to the top and sides of the box. The box is delivered collapsed to your home.

Another option is an insulated, zippered opening cover by Insulsure™. This cover is flexible and attached to plywood on the attic floor around the opening for a good seal. It is made of a flexible material filled with one-half inch of microfiber urethane insulation for R-3.2 insulation value. There is an optional reflective foil top to block the radiant heat from the hot roof during summer.

The third option, by Atticap™, is a domed, molded foam cover made of expanded polystyrene that is designed to fit over the stairs and opening. It is 60×30 by 9 inches high and weighs only about 8 pounds, yet has an insulation value of R-12. The following companies offer attic entrance products: Atticap, 888-292-2229, “draftcap.com (draftcap.com)”:http://www.draftcap.com; Battic Door, 508-320-9082, “batticdoor.com (batticdoor.com)”:http://www.batticdoor.com; and InsulSure, 877-660-5640, insulsure.com.

Send inquiries to James Dulley, Michigan Country Lines, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit dulley.com.