Home repair: No need to climb on roof to remove moss

Q. Prior to installing Z-Stop zinc strips, I recognized that I had to remove the moss buildup on the roof. It appears to be growing under the shingles and, in some cases, to be lifting the shingles.

Over the last few years, I have been manually removing the moss. It is a tedious, time-consuming job. The portions of the roof that I have worked on and then sprayed with Wet & Forget are holding up well.

The problem for me is age, plus heights, plus balance. I just can’t do it anymore. I will work with a contractor and wish to provide explicit instructions.

First, moss removal. How about power washing? I am concerned that the granular covering will be weakened and wash off, thus limiting the life of these expensive architectural shingles.

Second, is there an alternative to removing the moss by hand, shingle by shingle? Are there any guidelines for laying more zinc strips beyond the initial ridge cap (e.g., number of linear feet of roof surface from ridge to drip edge)? What would be the best post-moss removal cleaning solution that is environmentally sound? (My camp is close to the water’s edge.)

A. There is no reason to incur the risks of climbing on the roof. Moreover, it may cancel any claims you may want to file against the warranty in case of early shingle failure. (Collecting on shingle warranties is such a hassle, and most are pretty useless as it is.)

The zinc strips you installed just below the cap shingles at the ridge will kill all the moss, lichen and algae over time; it’s a question of patience. Thus there is no need to install more strips farther down the roof.

Power washing should not be used on a shingle roof for the very reason you mention: It will damage the mineral granules, which protect the asphalt binder from the UV rays of the sun. Rain, snow and wind should eventually remove the clumps of dead moss, the lichen blooms and the discoloration caused by the algae.

You certainly can spray Wet & Forget anytime you wish to speed up the cleaning (although it should not be necessary with the zinc strips); the manufacturer says it is ecologically safe.

Q. My home was built about 60 years ago. Recently, we had the bathroom painted. After two months, the paint started to peel above the shower on the wall in different spots, but not on the ceiling. This room has been painted several times in the last 44 years, and we have never had this problem. What can be done to repair this problem? What paint should we use?

A. Paint failure is usually caused by improper preparation of the surface. It may be that the shower walls had some splashes of soap scum or shampoo that were not thoroughly cleaned off.

You may need to remove the peeling paint, aggressively clean the affected areas and follow up with a primer such as B-I-N before applying the finish coat. A semigloss acrylic paint would be a good choice.

Q. What can I do to make my cedar deck less inviting to carpenter bees? How can I determine how much of the structural strength has been destroyed? We’ve had the exterminator out twice in as many weeks. The number of new holes in that time shocked the exterminator. The bees have even started to bore into the pressure-treated sections. Short of tearing the deck apart and replacing boards, is there a way to repair any damage?

A. Carpenter bees drill perfectly round holes and excavate tunnels in which to lay their eggs and raise their young. They can do considerable damage, depending on the extent of the tunnels they have drilled. They prefer unpainted and weathered wood but usually stay away from pressure-treated wood. It’s unusual that they didn’t in your case.

A good control seems to be to apply fresh paint to wood that has been attacked. Stains and other preservatives are not as reliable, but they offer some protection.

You can also spray an insecticide on all affected areas in the spring, before the bees begin looking for places to drill for their nests.

Here is a reprint from the University of Kentucky Entomology Department, which you may find helpful in controlling carpenter bees:

“Liquid sprays of carbaryl (Sevin), chlorpyrifos (Dursban) or a synthetic pyrethroid (e.g., permethrin or cyfluthrin) can be applied as a preventive to wood surfaces that are attracting bees. Residual effectiveness of these insecticides is often only one to two weeks, however, and the treatment may need to be repeated.

“Existing tunnels are best treated by puffing an insecticidal dust (e.g., 5 percent carbaryl) into the nest opening. Aerosol sprays labeled for wasp or bee control also are effective. Leave the hole open for a few days after treatment to allow the bees to contact and distribute the insecticide throughout the nest galleries. Then plug the entrance hole with a piece of wooden dowel coated with carpenter’s glue, or with wood putty. This will protect against future utilization of the old nesting tunnels and reduce the chances of wood decay.

“Although carpenter bees are less aggressive than wasps, female bees provisioning their nests will sting. Treatment is best performed at night when the bees are less active, or while wearing protective clothing.”

A word of caution: The insecticides mentioned may not be approved in your state. Please check with your local extension service to find out which products are approved in your area.

Q. I have a well and a pump, and every time we have a power interruption, the pump loses its prime and I have to call someone to prime it again. Why would this be? I am 84 years old and live alone, and on a recent holiday, it happened again. I didn’t know where to turn and was without water for hours.

A. You should call a well specialist or a licensed plumber familiar with wells (quite common in rural areas). Have them check the low cutoff switch and the foot valve. Dirt lodged on the foot valve may keep it from seating properly, causing water to leak through and empty the pipe, requiring repriming the pump. It may be possible to clean it once the pump is pulled out, or a new foot valve may need to be installed.

Q. I recently discovered four holes in my backyard, which I have been told are from moles or groundhogs. How can I get rid of them? I don’t want to twist my ankle or fall. What do they eat? There is no garbage around, and all the neighboring yards are well-kept. I have not seen these animals yet, but the holes are rather large.

Someone told me I should put mothballs down in the holes. Will that work? Will they try to come inside when it gets cold? Do you know anything that will help me?

A. The critters are more likely to be groundhogs, also known as woodchucks from an old Indian name. Moles do not dig up big holes, as they are small rodents.

Groundhogs eat new, succulent vegetation, berries and bugs, and they can easily decimate a vegetable garden. They like to sun themselves. They are wary and extremely hard to catch. Mothballs are unlikely to work, as they usually have several exit holes in an extensive tunnel network.

They are difficult to discourage but will not seek to come inside when the cold weather comes, as they hibernate.

They can be trapped in a Havahart trap and relocated at least five miles away if that is allowed in your state, or they can be destroyed by throwing special lethal bombs in their burrows, preferably at night. But you will need to seal the other exits, if you can find them, with large rocks.

Either method is best left to experienced pest control operators or professional trappers.

Q. I’ve been doing improvements in my 48-year-old house. The last one was to install storm windows throughout. I installed vinyl storm windows, replacing the old wooden ones. The lower level of our house is concrete blocks, and it is cold down there! There is no heat.

Should I have replaced the storm windows with wood ones instead of vinyl? Would it have made a difference?

The room is paneled (48-year-old paneling), but there is no insulation behind it. We do use this room. I’d appreciate your suggestions.

A. The type of storm windows should have little bearing as long as they have been installed properly. The coldness of the room is due to the uninsulated block walls.

You have several choices: You can remove the old paneling, insulate the walls and repanel; you can install rigid insulation over the old paneling and install new paneling; or you can add heat with through-the-wall units like Rinnai vented space heaters, if you have gas heat upstairs. If you heat with oil, and if your heating appliance has enough spare capacity, ask a heating contractor to give you a quote for adding heat downstairs. Otherwise, electric heat may be the best option.

INTERESTING PRODUCT: A lot has been written about toxic chemicals leaching out of plastic drinking bottles. Concerned about this, we have switched to stainless steel bottles.

Now I have learned about a new product: a glass bottle that is encased in a clear protective coating. If the glass breaks, there is no risk of injury and the contents are contained, preventing a messy spill. You can see the two bottle sizes and read more about them at www.PUREGlassBottle.com.

DEAR READERS: Here is a maintenance tip gathered from an unpleasant experience. We have had new smoke detectors installed as part of a remodeling of our house. Recently the alarm went off for a few seconds, startling us. I investigated and found out that the alarms are sensitive to pollen, dust in the air and small insects. The manufacturer recommends that smoke detectors be vacuumed as part of housecleaning. And, of course, batteries should be replaced every year; a good time to do so is when you turn back the clocks in the fall.

Another disturbing thought is that the rate of manufacturing defects for smoke detectors is alarming. A few months ago, one of our detectors sounded an alarm in the middle of a winter night. I raced all over the house to see what was happening, since we didn’t smell any smoke.

Everything was OK, but we had no idea which of the seven detectors was giving us a false alarm. We called the fire department and said there was no emergency but we needed help. The fire chief himself came to our house and, using a ladder, deactivated the culprit, which was very high near the top of a cathedral ceiling.

He later confirmed what our electrician told us after this episode — that he had to replace one in three defective smoke detectors. The fire chief told me that we were lucky to have had only one defective detector to date. He also said the problem was across all the brands so it would make no difference to switch to a different brand, and that doing so may require expensive electrical work.

Ÿ Henri de Marne was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. Write to him in care of the Daily Herald, P.O. Box 280, Arlington Heights, IL 60006, or via email at henridemarne@gmavt.net. His book, “About the House,” is available at www.upperaccess.com and in bookstores.

© 2012, United Feature Syndicate Inc.