The Toolbox: Attic insulator, cleaning roof streaks

Stopping attic heat loss

Chances are your pull-down attic stairs are costing you money.

Uninsulated attic hatches are a common spot where heated air escapes into an attic. Owens Corning's Attic Stairway Insulator makes it easy to stop that heat transfer.

The insulator is a tent made from insulating material and reflective foil that covers the stairway opening. It's lightweight, so you can just move it aside when you need access to the attic and put it back when you leave.

The product will cover an opening up to 25 by 54 inches.

It's available from building supply stores and home centers including Home Depot. You can find a retailer that carries Owens Corning products by using the store locator at http://insulation.owenscorning.com/homeowners, but call the store first to make sure it carries the stairway insulator.

Suggested retail price is $53.95.

A: Those streaks are caused by an algae-like bacteria called Gloeocapsa magma. It spreads via airborne spores and feeds on the calcium carbonate in the crushed limestone that's used in some asphalt shingles.

If your shingles are in good condition, you can scrub the roof lightly with a solution of chlorine bleach and water or a product made for cleaning the streaks. However, you need to be very careful not to damage the shingles. Protect your skin and eyes if you use bleach, and take proper precautions for working on a roof. You should also protect the plants that may be affected by watering them well beforehand and rinsing them afterward.

You might be better off hiring a professional to clean the roof. You can find roof cleaners in the Yellow Pages, or ask a roofing contractor you trust if he can do the work or suggest someone who can.

To prevent the streaks from returning, you can install copper or zinc strips under the shingles at the top of the roof, leaving part of the metal exposed. Rainwater will carry tiny amounts of the metal down the roof and kill the bacteria.