Home repair: Second layer of shingles carries risk

Q. Can a second layer of shingles be added to a single layer of architectural shingles when the latter wear out? It seems the architectural shingles would be too lumpy, necessitating full tear-off before new shingles could be installed.

A. Before adding a second layer of shingles, one must be certain that the rafters are going to be able to take the additional weight. This is of particular concern in areas of heavy snow. To make sure, a contractor experienced with the use of span tables or a structural engineer should be consulted.

You are right in thinking the new shingles will not look good over the existing architectural shingles. The sun will make the new ones telegraph the old ones and the roof will look “lumpy,” as you put it so well.

Q. My husband and I have read your excellent column ever since moving to Vermont in the early ’80s. In 1986, we moved into a house in Burlington that was built around 1908. The house has a stone foundation, and the house sits at the top of a hill. Our “water in the basement” problem is a result of a hole cut out of the cement floor (see attached picture). Someone once told us the name of this arrangement, but they didn’t know its purpose, and neither do we. We know that when the groundwater is saturated, a lot of water comes up in this hole and floods our basement. During the most recent rain, we shut off the pump (a seasonal inconvenience) for a few hours and the basement became totally flooded again. Our questions to you are: 1) What is this thing and its purpose? 2) Is there some way to stop this backflow into our basement?

A. This “thing” is the hole for the house trap, which prevents sewer gases from entering the house. They have screw-on caps that allow for snaking the line if the need arises. Modern plumbing requires a trap under each fixture, but in the earlier days, some fixtures may not have had a trap or had siphon traps that can lose their seal if a basin full of water drains fast, so the house trap was there to provide the needed seal against sewer gases.

Such traps are no longer of any use, but I would not recommend eliminating it, as your plumbing may still need it if it has any of the features mentioned above. A licensed plumber or code official can answer that question for you if you are considering getting rid of it. However, I can’t see the trap in the photo you sent; perhaps it is now buried in the soil that repeated leakage may have brought in.

If the water that floods your basement is clear and odorless, it is not coming from the sewer line. If it were, you’d have a major stink in the house. The leakage is likely caused by a rising water table, and the way to control it is by having a submersible sump pump of a capacity to keep up with the inflow.

Q. I am spending the summer repainting the rooms in my house. I am not the best or most careful painter. To keep paint from messing up adjacent surfaces, I use painter’s tape that peels off easily without leaving a residue, but I find that paint creeps under the tape, and I have a mess on my hands. Do you have a suggestion on how to avoid this?

A. Try FrogTape. The manufacturer claims FrogTape is treated with PaintBlock technology — a super-absorbent polymer that absorbs and traps liquid latex paint and keeps it from bleeding under the tape. FrogTape is available at Lowe’s, Sherwin-Williams and other fine paint and hardware retailers nationwide. Check www.frogtape.com for more information.

Q. I read your column that dealt predominantly with roofing. The questions and answers from this column answered a lot of my questions regarding re-roofing the house. However, I still have several questions that you could help me with. We live in the Chicago area, where the winters can be cold with heavy snow and the summers are very hot and humid. I want to make sure the products we install will last at least 25 years.

In getting quotations, one of the contractors wanted to use Owens Corning Duration Series shingles. Is this a good product? Also, we want to have new siding installed. We have received a quote on Vortex Extreme siding manufactured by Variform. Have you heard of this product?

Could you please explain again how to roof the valleys?

A. I have no long-range experience or opinion about the Owens Corning Duration Series shingles, and you cannot depend on the warranties that manufacturers claim. Time and time again, shingles with warranties of 25 or more years have failed in half the time — and that applies to several brands. The only brand I have heard to have no problems so far are the BP shingles I have recommended and use on our house. Only time will tell if they stand up.

I have no experience with Variform siding, never having seen the product installed.

The best valleys are made of metal, copper being the top choice but expensive. Aluminum and galvanized metal are also fine and less expensive, and they come in several colors. They should be made of the heaviest gauge available and, for valleys longer than 6 feet to 8 feet, made in several sections. Overlaps between sections need to be a minimum of 6 inches. Each section should be nailed only at the top and held in place with clips along its sides to allow for expansion and contraction. That means shingles must not be nailed through the metal. An ice and water membrane should be applied in the valley before the metal is installed and can also be applied on each side of the valley under the shingles. At the eaves, the bottom section of the metal should be kept straight across and not cut to fit the angle of the roof planes in order to keep water away from the fascia. Ideally, there should be an inverted “V” in the center of the valley to keep water on each of its sides. This is used as a matter of course in some parts of the country, but not in many others.

Closed-cut and woven valleys made with the roof shingles are widely used by builders because they are faster, save time and do away with the metal, but the best roofers will not use them. Besides requiring several installation steps which I have not seen done correctly — leaving the valley vulnerable to leakage — these valleys do not last as long as the rest of the roof does, because water from each roof plane meets in them and the rushing current wears out the shingles.

Q. I am considering buying a pressure washer. The electric ones are so much less expensive than the gas ones. Which would you recommend?

A. I have not used an electric pressure washer, so I am not able to tell you if they are as powerful as the gas-powered ones. The obvious shortcoming to the electric ones is that they are tied to an electrical cord and conveniently located plugs, which can limit their range. I have a Briggs & Stratton gas-powered pressure washer that is very portable, lightweight and easy to fit in the back of the car.

Q. Twenty-two years ago, I purchased a house with 6-year-old unpainted, pressure-treated, 2-by-6 decking. I treated it annually with Benjamin Moore exterior stain for deck and siding. It worked well. The surface of the deck was hard and water beaded on it. A few years ago, a friend suggested using Behr Premium Weatherproofing and Wood Sealer Finish, a penetrating oil formula. After using this, the deck finish turned milky white and never seemed to get dry or hard, but gummy instead. The next year, I reapplied the Benjamin Moore product, but the finish is still gummy and wants to absorb water. I have tried sanding and pressure-washing with no success.

A. I wish you had not followed your friend’s advice. I have had several readers write me with similar problems with Behr products and have seen these problems in my consulting work in a couple of condo projects. The manufacturer or the dealer who sold it to you will tell you that you did not use the product properly. If you applied the product with a roller, that may be the case, as the film ended up too thick, particularly when applied over an existing sealer that prevented absorption of the Behr finish.

You will have to remove the latest Benjamin Moore application and the Behr finish. You can do this by using Benjamin Moore REMOVE, a concentrate that is mixed with water and applied with a garden sprayer. Follow directions and allow it to do its work, then scrub the surface with a stiff brush and remove the sludge with a pressure washer or a garden hose with a high-pressure nozzle. When the deck has thoroughly dried, stick with the Benjamin Moore sealer that you first used and reapply it yearly as you did in the past — do so thinly.

Q. I love that French Canadian name! We were at dinner last night and our friends brought up septic systems. Our septic system is about 25 years old with no problems so far, and all is still looking good. We used to add something to the system once a month but stopped some years ago when our septic guy said not to add anything to our system. Our friends mentioned how they purchase yeast in bulk at Costco and add it once a month. What do you recommend? We usually pump out every three to four years.

A. Sorry, not French Canadian, but real Parisian from La Belle France and thoroughly Americanized since 1946!

Your septic guy is right; nothing should be added to a septic system. Everything needed for the proper functioning of a septic system is in our intestinal tracts. A university study has actually demonstrated that adding enzymes of any kind to a septic tank has a detrimental effect, despite the periodic “septic guy” on television who tells us that if we don’t use the product he is hawking, our system will fail and our house will be flooded with septic effluent.

Years ago, when I visited some old friends in a remote Maine area, I saw a sign above their toilet that said, “Don’t throw nuttin in heah that you ain’t et feust.” Wise advice and the rule to follow.

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.

$PHOTOCREDIT_ON$© 2011, United Feature Syndicate Inc.$PHOTOCREDIT_OFF$