Handyman on call

Lichen on roof is OK, but moss isn't

By Peter Hotton
February 8, 2009

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Q. A handyman scraped off moss from my cedar roof shingles, and really dug into the wood. How can that moss be removed without damaging the wood? I was told the moss is not moss, but lichen, a light green growth about the size of a half dollar. It was very difficult to remove. What can I do now?
MARY, Lincoln

A. In this business, we have to define our terms. If your man knew the stuff was lichen, and not moss, he would not have to gouge the cedar shingles to get it off.

Lichen will do no harm to wood; and can be left on, partly because it is often very difficult to take off. Often we see lichen on trees, and it does no harm to them, either.

Moss, on the other hand, the dark green growth related to ferns (they grow from spores, not seeds), should be removed from wood roof shingles because it grows in a damp environment, which if left on the wood will decay it. It is easily removed with a wide putty knife.

Q. The painted steel heat covers over my radiators have developed little rust dots. I sanded off the rust dots, primed and painted, and before long the rust dots showed up again. What did I do wrong and how can I avoid the dots in the future?

A. You used a latex primer and paint. The water in the primer and paint caused the rust dots. To avoid future rust, sand off the rust spots and treat them with Rust Reformer, which contains phosphoric acid, and turns the rust black and makes it paintable. Use an oil-based primer and paint. The same rule applies to tin ceilings, which are really steel panels. That is, if you ever paint a tin ceiling.

Q. I received a free water heater, but the water smells of sulfur or rotten eggs. Someone suggested I cut a few inches off the anode rod. What else can I do?
BARBARA MacTURK, Hailesboro, N.Y.

A. That's hydrogen sulfide, which occurs naturally suspended in water or as bacteria. If you have a well, the bacteria can be killed with a bleach treatment. Cutting the anode rod may work; the rod is in the heater as a self-destructive unit to prevent corrosion of other parts of the heater and extend its life. One reasonable treatment is to let the water run until the odor goes away. The presence of hydrogen sulphide or some bacteria in the water is not considered harmful to your health.

Q. My 1910 vertical steam pipes are peeling badly. How can I prevent that?

A. I think the peeling is due to the high heat of the pipes, which can get close to 212 degrees. Sand thoroughly, and paint with a high heat resistant spray paint. Krylon makes one. If you can't handle spray paint in the house, you might be able to find a brushable HHR paint at a paint store.

Here is another idea: If you use the pipes to help heat the room, build a wood box around each pipe with a decorative screen on two sides to provide the needed heat. Paint this; it should resist peeling. Use oil or HHR paint. Do not use latex, as the heat will turn the paint brown.

'Weeping' sewer pipe
When a caller from Vermont asked about a weeping 70-year-old cast iron sewer pipe in his cellar, which was forming a crust, the Handyman suggested it was condensation and not to worry about it. It can be stopped, the Handyman wrote, by ventilating the basement.

Michael E. John, a builder for 25 years, disagreed with the Handyman, and e-mailed:

Your suggesting that the water dripping from the bottom of a cast iron sewer pipe was condensation was most likely incorrect and potentially dangerous. I write from experience as I have owned a home for 34 years that had the same problem. From 1975 when I bought the house until about 1987 I always thought that the line of "drips" along the floor the length of the house was condensation. I swept the dirt and dust including the "drips" for years. What a shock it was when part of the bottom of the pipe fell out in 1987 and the rest of what goes with the "drips" was on the cellar floor. I hired a plumber to replace the entire system in the cellar with abs (plastic) and he told me that the "drips" all of those years had been sewage water not condensation. Since 1987 I have bought and now own five more older apartment houses and have seen this again.

I bought one of them in 1997 and saw the tell-tale "drips" on the floor and checked the pipe simply by hitting the bottom of it fairly hard with a carpenter's hammer in several spots. The hammer broke through as I suspected it would and that pipe was replaced with abs. As you may know you have to hit good cast iron many times real hard to break it. I also have houses with still good but old cast iron. I have never seen condensation on any sewer drain pipe in any of my houses. I own one house that was built in the late 19th century and the cast iron still looks new. I suspect today there are manufacturing standards for cast iron sewer pipes but 100 years ago maybe there was good quality and poor quality pipes being built and that is why some go bad and some don't.

Thank you, Michael John. We hope that the caller from Vermont will see this.

Q. Ever since I had a new roof installed and a ridge vent put in, I have gotten a lot of debris and tree stuff such as pollen filtering into the attic through the ridge vent. So much that it covers things that I store up there. What is happening? Can I fix it?

A. Do you have soffit vents, (vents in the underside of the roof overhang)? If there are no soffit vents, or they are too small, the ridge vent may not be exhausting air but bringing it in, along with the debris. Much of the debris occurred when the new roof was installed, but that does not account for the tree material. You can cover the stored items with tarps. And check soffits for vents or lack of them.

Q. I inherited some old ladder back chairs with rush seats. They have great sentimental value and I would like to keep them, but they are mighty loose, rocking from side to side and front to back. How do I fix them, and what kind of glue should I use? Where can I buy rush, cane, and wicker material to help keep the chairs and other furniture good looking?

A. The only right way is to take the chairs apart and reglue all spindles, connectors, and other supporting parts. I think Elmer's carpenter's glue is quite good, and easy to work with. The new urethanes, such as Gorilla Glue, are also good but they are tricky, some needing wetting before gluing. And instead of buying a whole bunch of clamps, you can hold the chairs together tourniquet fashion, running a rope around the connection and inserting a wood stick as a tourniquet. I did that once, got carried away and broke the rope.

One more trick: If you find some of the holes for the spindles rather looser than they should be, you can insert little aluminum inserts, shaped like a cheese grater, in the holes to make the spindle hold better. They take the place of match sticks and other sliver inserts.

Find rush, cane, and wicker materials, including sea grass rush and fiber rush in the Rockler Catalog, 1-800-279-4441.

Handyman on Call also appears in g on Thursdays. Peter Hotton is available 1 to 6 p.m. Tuesdays to answer questions on house repair; call 617-929-2930. Hotton chats online about house matters 2 to 3 p.m. Thursdays, at Hotton can be reached at