Q Our church building has a flat roof with a felt-pitch covering. It is old and has developed several leaks. Is there an alternative to a new roof, such as a membrane-type covering, which is fairly inexpensive? Jeff Stevens Webster, Texas With a flat roof (or any roof) you have only two ways to go. You either keep patching, or you put on a new roof.
A new roof of any type requires a sound surface to which it can be bonded. Placing a membrane, such as a 90-pound mineral-surfaced cap sheet, will work for a few more years, but bubbles could develop in hot weather if the underneath layers are not in good shape. This causes separation at the lap joints.
I suggest you establish a budget and then ask a couple of reputable roofers what they can do for that price. Q I would like to repaint the inside of a rental apartment and am told there is a solution which makes it unnecessary to wash the walls and woodwork first. Is this right? Nadine Shidley Monrovia, Calif.
The most effective way to prepare the surface is to wipe the walls with a solution of water and trisodium phosphate (TSP), which removes the grime and cuts the gloss of enamel.
A product called Liquid Sandpaper also cuts the gloss and eliminates a need to sand prior to repainting. Q A friend of mine had never had a mildew problem in her attic until last year when she installed an air humidifier in the furnace. Now the problem is severe. There is no ventilation in the attic. Mrs. John Merkens Hamburg, N.Y.
Darkness, moisture, and still air are excellent breeding grounds for mold. The humidifier in some way allows the moisture to get into the attic and, of course, from there it has no place to go.
First, the attic should be vented in such a way that air will flow through it. Provide some louvered dormer vents near the upper portion of the roof and screened openings under the eaves into the attic. This should help to solve the problem.
Carefully inspect the heating system to see if it is allowing moist air to somehow creep into the attic. Q After our church building was reroofed with asphalt shingles, the roof developed leaks along the rake at the gable end. There is a piece of copper and lead flashing that trims out the edge, with the shingles butting tightly against it. Is this the proper construction method, or should there be a space between the shingle edges and the raised edge of the flashing? Richard V. Nielsen Williston Park, N.Y.
In the case of your roof (having looked at photos), it seems that the joint between the flashing and the shingles should be thoroughly sealed with roofing mastic to prevent the water from being pulled between the shingles by capillary action.
The job may have originally been done using tin shingles, a method of counterflashing between the shingles and tying vertically into the flashing strip. It would take some investigative work to find this out, however.
I believe a good sealing between the shingles at the rake and between them and the flashing will stop the leaking.
If you have a question about designing, improving, or maintaining your home, send it to the real estate editor, The Christian Science Monitor, One Norway Street, Boston, Mass. 02115. Richard A. Kent is a practicing architect and general contractor in southern California.