Home repair: Water stains require complex solution

Q. I have a two-story brick and cedar-sided home built four years ago. There is a bayed area in my dining room that is covered by a copper roof outside. A few years ago, we had some water stains show up in the drywall ceiling of this area. My builder and the roofer who installed the cooper roof concluded that the brick sills of the two windows on the second floor above the copper roof must be absorbing moisture, which is draining onto the drywall ceiling. My builder had the brick sills replaced with limestone ones, and there was a rubber membrane installed under the first course of bricks under each of the limestone sills.

Last week, we had a rainstorm that dumped three inches of rain in about 90 minutes. The following day, I noticed that the drywall ceiling was not only stained worse than the first time but the drywall was so wet that it is soft to the touch and one area was almost black. We removed the window treatments from around this area and discovered that the wainscoting on one side was popping off the wall and the joints were coming apart. The wall on the side where trim is moving also felt slightly damp. In addition, the oil paint on part of the trim developed raised ridges with cracks, and some of it actually flaked off. Plus some of the joint compound from the area where the wall meets the ceiling popped off, too.

Obviously, we have some water intrusion, but we are at a loss as to what the problem could be, as the copper roof seems to be in good condition and properly sealed to the brickwork. What could be causing this problem? Does the drywall ceiling need to be replaced? Am I overlooking anything else?

A. Thank you for sending the photos. The copper roof was installed incorrectly. The major damage you suffered in the last heavy rainstorm accentuated the problems in its installation.

Ÿ The standing seams are not sealed at either the top or the bottom. The four seams on the front of the bay should have been flattened and covered with the horizontal counter flashing or should have had their tops soldered. The top of the two seams abutting the front seams on both sides of the bay should have been soldered to them or sealed with a soldered cap. The other seams abutting the wall flashing should have been either flattened and covered by the wall’s counter flashing or have had their ends capped and soldered.

The bottom of all the standing seams should also have been caulked and sealed either with a tab cut out of the bottom of the copper sheet that is wrapped over the drip edge or with a piece soldered over their ends.

The one-piece flashings on each side of the roof were not done correctly. Not only do they appear to be just caulked to the bricks. (I can’t see the end cuts in the mortar joints that would show if a saw cut had been made in the joints to fit a reglet for the counter flashing that should cover a turned-up leg of the copper pan, which should be at least several inches up the brick wall.) It also looks as if the bottom of the single piece of counter flashing is turned over the copper roof by an inch or so, which leads me to believe that the leg of the copper sheet, if there is one, does not go high enough against the brick wall.

Ÿ The close-up of the left side of the copper roof shows more clearly the installation of the counter flashing. It is made of one piece of copper with slanted wings. The usual way of installing counter flashing in masonry is to insert single pieces with vertical drops (as opposed to the slanted ones) into each brick course as the wall is built. These pieces cover the turned-up leg of the pan. This does not appear to be the case. This is most unusual, as it seems as if this one-piece flashing has been applied on the face of the bricks and caulked. But, when looking at the damage on the ceiling, it seems as if the major leakage is taking place closer to the bottom of the bay-window roof, and not against the brick wall, which would exonerate the brick sills above the bay. I suspect that water flowing down the brick wall and bouncing off the copper is entering the roof through the standing seams because they are not sealed as they should be. The water then travels on top of whatever sheathing is under the copper until it finds a way inside the house.

One thing that is not clear is what is beneath the copper roof. Assuming that the lintel across the opening is at the ceiling level, how is the roof sheathing tied into the brick wall? What is the sheathing covered with — felt or rosin paper? The entire bay roof should have been covered with a waterproof membrane.

Another more remote possibility is that the bricks are absorbing water. If they haven’t been sealed, doing so is worth a try. A clear siloxane-base sealer is the type to use.

The roof needs to be replaced by someone experienced in the installation of standing-seam roofing, and the damaged drywall and trim replaced.

Q. Enclosed is a picture of my roof. It faces north and gets only a few weeks of direct sun. I have noticed this phenomenon on other houses with mostly gray and/or black shingles, usually surrounded by trees that cut the direct sunlight for most of the day. I assume it is related to some kind of pre-moss or an unknown organism that will morph from my roof and begin attacking human beings and threatening the world’s existence. How do I fix this and prevent this possible tragedy? The fate of the world rests in your hands!

A. The photo you sent illustrates a typical algae infestation common with asphalt roof shingles, regardless of the color of the roof. In the South, where most shingles are white or light colored, the same problem is widely found. The preventive measure is to install zinc strips just below the ridge-cap shingles. It will take quite some time for you to begin to see results. You can get zinc strips from www.stainhandler.com. If you are in a hurry for results, they also sell a roof cleaner.

The predicted world catastrophe, undoubtedly tied to the morphing of these nasty algae, has been avoided, thanks to some mysterious intervention. You can sleep more easily.

Q. Is there a product that can take tire marks off a concrete driveway?

A. You can try to burn them off with a butane torch. If they are deeply ingrained, try Mason’s Select Concrete Cleaner. You should be able to find it in hardware, paint and big-box stores. Be sure to follow directions, as it can harm some surfaces.

Q. I have a friend who would like your advice relative to the covering for a shed-dormer roof. The surface area is 22 feet by 14 feet. It faces southerly, which endures intense heat from the summer sun as well as prevailing winds. The slope is 2½-inch vertical to 12-inch horizontal. Years ago, membrane roofing (ice-and-water shield) was installed on the entire area on top of the wood sheathing. Selvage-edge or half-lap roofing was placed on top of this.

After a few years, there seems to be a so-called “creep” and cracking that takes place, especially at the horizontal half-lap joints. This has required additional tar coatings, at the horizontal joints every five years at the most since installation. Some minor leaking has also occurred, as evidenced in the ceiling below. Is ice-and-water shield compatible with the selvage-edge roll roofing on top?

Although it may be irrelevant there was a continuous ridge vent installed during the original application. This roofing is to be replaced this summer. What would you recommend for roof-covering replacement with these existing conditions in mind? Of course, I assume asphalt strip shingles are out, unless the roof slope is at least 3 to 12 inches. Your reply will be most appreciated.

A. When you say “years ago,” how many is that? Roll roofing has a usual life of about 10 years. Under sun and heat conditions, the deterioration may occur sooner, especially if the roll roofing is black or very dark. The best replacement is a synthetic rubber roof. The old roofing will have to be removed and a layer of fiberboard or XPS insulation laid over the deck to cushion the rubber roof against thermal movements. Rubber roofing is now used widely on residential buildings, as the price of the material has gotten better and the installation by general contractors has become more common.

Q. I always find your column helpful. With the snow melted off the roof, I am reminded of the moss that appeared there last summer. Recalling your advice in an earlier column, could you remind me of the proper formula of water to vinegar to spray on the roof?

A. The proportions are three parts white vinegar to one part water. Good luck. It will take time for results to show. The moss should turn brown but will not fall off until strong winds, snow or a driving rain dislodges it.

Q. I am the treasurer of 39 townhouses, all built in 1999. We have Hardie Plank clapboards that were originally painted. The association wants to stain the clapboards now. Is this advisable? I have talked with paint companies and painters. There is a mixed view on the answer.

A. It is best to stick with paint, as the original paint may prevent an even penetration of the new stain.

Q. Do you recommend any particular granite sealer and polisher? I read your column every Sunday and have used your recommended furniture polish, Milsek, which works great. There are just too many companies out there all claiming that their product works best. Our granite countertops were pre-sealed by the installer (so he says) about six months ago.

A. One good sealer is DuPont’s Bulletproof, which should be available at stores selling granite. There is no way to tell if a granite top has been sealed, so you can either take the word of the installer or, if you prefer, you can simply seal it again, because it won’t hurt to do it again. If sealed, or once resealed, it should not need to be done for another three to five years.

Q. I have noticed this year that my toilets (tank) and main water line (coming into the house) are sweating so much I have to put towels under them to keep water off the floor.

The weather isn’t even that warm yet. I checked today, and the water in the downstairs toilet tank was 53 degrees. Air temp was 65. I understand the concept of condensation, but it seems really bad. What can I do apart from using tons of towels?

A. I am assuming you have a well, and that its water is very cold. Although you can insulate the cold-water line where visible, I am not in favor of it, as it transfers more cold water into the pipes within walls, where it can cause hidden damage. You can try installing a storage tank just past the pressure tank so the well water has a chance to get conditioned to the environment before being drawn. Both the pressure tank and the storage tank should be set in pans to collect condensation in order to keep it off the floor. You can also buy insulated kits to put inside the toilet tanks, but that won’t help with the water line.

Q. Ever since I put an addition on my house, I get water leaks in the kitchen every year; snow or hard rain does it. I have put on three roofs, to no avail; it still leaks. Where do I go to fix the problem?

A. You haven’t given me much information. Where does it leak? If at the joint of the existing house and of the addition, it is likely that a flashing problem exists. I need more details (and a photo would be helpful) to do a better job.

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.

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