Question: How can I locate a bathtub no longer than 54 inches? I am being told by my plumber that no such thing exists, and that I will end up having to knock out a wall to accommodate a larger tub. That is not something I can afford. I can't believe how difficult it has become to simply replace my tub, and I am very worried that it will begin to leak as there is significant rust around the drain and enamel erosion.

Can you comment on reglazing the current tub or replacing it with a "walk-in tub"? Are these viable and durable options? I have definitely ruled out the overlay-type tubs that fit over the existing tub - I have been told there is a problem with mold.

Answer: I don't agree completely with your plumber. If you check the Internet, you'll find 54-inch porcelain Victorian-reproduction clawfoot tubs that probably cost more than knocking out a wall would. I came across three in only a brief search, costing $1,000 to $1,500. They also make 54-by-54-inch corner Whirlpool tubs, but your bathroom probably won't accommodate one.

Fifty-four-inch tubs are uncomfortable for anyone taller than about 5 feet. That's why they don't make a lot of them these days.

Now, as for your second question, which was posed by another reader as well: You can have the tub refinished; such companies are listed in the Yellow Pages. You'll need to get a written warranty from the company, since many of these refinishing systems don't guarantee the new finish will last more than a few years, and then you've spent the money and end up with the same problem.

Walk-in tubs are designed to accommodate people with disabilities. Although I've seen low-end models for about $500, the better ones range from $2,500 to more than $6,000. Spending that kind of money is about the same price as knocking down a wall.

Finally, I've heard of mold issues only with badly done overlays. Satisfaction is determined primarily by the care you take in hiring someone to do the job.

Q: I have black algae on my asphalt-shingled roof and have found that it is removed nicely by using 5 percent sodium hypochlorite. However, I wonder if there isn't a less chemically active product that I can use, since I don't want to destroy the shingles.

A: Oxygen, or oxygenated, bleach is one way of removing the black algae that is being bred by the newest generation of asphalt roofing shingles. Three types of oxygen bleaches are widely available: hydrogen peroxide, sodium percarbonate and sodium perborate.

OxiClean is oxygenated bleach and can be found in the laundry-detergent aisle at supermarkets. It may or may not work on black algae; I've never tried it. But for information on products that are available, what they do, and their cost, see

The reason oxygen bleach is recommended for cleaning algae is that chlorine bleach can damage the shingles; so can scrubbing them. To remove the algae, spray them with an oxygenated bleach solution (the powdered variety and water; follow directions on the container), wait the recommended period, and then gently wash the shingles with a hose.

Don't power wash. It can damage shingles and remove their granular coating.

To prevent algae growth, roofers nail copper and zinc strips at the peaks, so that rain washing over the strips produces metal salts that kill algae on shingles below. Some manufacturers are impregnating shingles with copper and zinc.

Newer shingles foster algae growth because of the filler used in them. Manufacturers switched from rag filler to limestone, which creates food for the algae.

Have questions for Alan J. Heavens? E-mail him at or write him at The Inquirer, Box 8263, Philadelphia 19101.