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handyman on call

Is it possible to take steps to deter mold?

Q. My attic had major flooding from frozen water pipes, including a ruined ceiling that will be replaced. Will there be any mold resulting from the flooding, wet attic areas, and the very wet ceiling that actually collapsed, and is there a way to prevent mildew? Would treating the ceiling joists with a 1 to 3 bleach-water solution help prevent future mold?

SALLY ROGERS, MELROSE

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A. First, let me pin a gold medal on you, Sally, for asking a question never before asked of the Handyman in his 36 years of service. How to prevent a recurrence. Yes, there have been questions of recurrence after treatment, but you asked if mold can occur when there was never any mold in the first place.

I think mold is unlikely to occur after you dried out the attic and provided enough ventilation, because there were no mold spores lurking around waiting to pounce on a damp surface and multiply. No guarantees, but adding a bleach solution on ceiling joists (and the under part of the attic floor) can be a good prophylactic, doing a lot for preventing occurrence. So, keep your eyes peeled for any black stains, tiny black dots, although some mold is white, and rarely, other colors. And keep your nose peeled for mold smells, and mustiness.

Q. Our house has an external brick chimney on the gable end. Today I noticed that the sheathing behind the chimney in the attic was wet. The flashing on the chimney is relatively new and looks fine as do the shingles. There are no puddles on the attic floor or stains on the living room ceiling below. Only the inside of the sheathing boards is wet. This is the only wet place in the attic. I am wondering if the heat from the chimney is radiating through the sheathing and causing condensation in our very cold attic. If so, would putting some foam insulation board in the stud bays behind the chimney cure the problem?

PHIL BAIMAS

A. It is not the heat of the chimney that is causing the condensation, but rather this: The attic, being very cold, is well insulated (on the floor) and well vented. So water vapor getting into the attic is condensing on the sheathing because it is made cooler by the brick chimney. Putting Styrofoam rigid insulation on the sheathing between the studs in the offending area will solve that problem. If condensation appears elsewhere in the attic, the attic needs more ventilation.

Q. How can I remove a 12-inch yellow stain from a bathtub? A rubber mat was left in the tub after showers were taken. I tried bleach and Mr. Clean Magic Eraser and neither of these worked.

ANNE FOLEY

A. Try this: add hydrogen peroxide (wet the stain thoroughly), add cream of tartar, leave overnight (add more hydrogen peroxide to keep it wet), and scrub and rinse in the morning. Or scrub with Bon Ami, Comet, or any scouring powder.

Q. I bought a condo in Concord, I see that a lot of dirt is being tracked in. It was recommended to use a steam cleaner on my hardwood floors, but wouldn’t that allow excessive water on the floors?

CONCERNED

A. Yes indeed, so I suggest you use a wet Swiffer. A Swiffer with a spray may be too wet. Consider also welcome mats outside, and a small throw rug inside each door. Maybe have the outdoor mats tell the walker, wipe your feet!

Q. Are ceramic tiles as waterproof as porcelain tiles? What kind and size tiles are good for a small bathroom?

ESTHER WHITMAN, REVERE

A. Ceramic tiles are clay with a glaze on top and sides, making them as waterproof as porcelain tiles, which are solid china, like your toilet. For a small bathroom use small tiles: 4 1/4 inches square, or mosaics, tiles as small as 1 inch square.

Q. I had a new roof installed on my ranch, with ice and water shield, and a gutter guard on top of the gutters. Roofers said the roof, gutter guard, and ice and water shield will prevent ice dams. Then, after a great deal of snow and ice piled high on the gutters this month, the roofers told us nothing. What gives?

HELEN, FROM HOLLISTON

A. Severe snowfalls and cold will cause build up on empty gutters, gutters with gutter guards, and anything on gutters, no matter what. The roofers didn’t tell you because they assumed you’d be able to figure it out. The gutters will eventually allow water to flow away safely and conveniently.

Peter Hotton is also in the g section on Thursdays. He is available 1-6 p.m. Tuesdays to answer questions. Call 617-929-2930 or e-mail photton@globe.com. He also chats online 2-3 p.m. Thursdays on www.Boston.com
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