Dust, rather than mold, likely cause of stained cathedral ceilings
Q. I hope you can shed some light on the source of black lines on my cathedral ceilings. I have been told that it's from condensation built up in the attic. All the rooms in my unit are affected, except the second bedroom, where the ceiling is a normal height and flat. You have often mentioned in your column the challenge of insulating cathedral ceilings. This problem occurred two to three years after I moved in, 12 years ago. I had the unit painted, and three to four years later, the same black lines appear. My association covered the cost of blown-in insulation, but my concern is the root cause. Could it be mold? If the problem is coming from outside my unit, which most folks think, then my association may have to repair and paint.
A. Several of the photos you sent are of gable trusses that clearly show the framing members. The dark marks on the wall spaces between these members indicate there is an insulation problem. These wall areas are cooled by the lack of, or poorly applied, insulation, causing them to have a slight moist surface. Dust floating in the air sticks to them resulting in the dark areas. One very dark area around a ceiling fan exhibits the same problem: cold air comes in contact with the drywall ceiling. Where there are dark lines on a flat ceiling, it usually means that the insulation between the floor joists is OK, but that cold air is creeping alongside the framing members - the ceiling joists - or that there is no insulation over them in an attic, causing them to be cooler than the insulated spaces between them. In cathedral ceilings, dark marks on rafters and areas between them usually indicate that there is high humidity in the roof cavity.
Where there are dark lines at the top of the walls, the blown-in insulation may have settled or the spaces were not fully filled. If the association had insulation blown-in in the cathedral ceilings, there must not be any ventilation, as it would be impossible to do so after the fact and preserve any vented space, unless there are solid baffles, which is doubtful. Most baffles used in condo projects are foam and quite flimsy. I need more details on the construction of the roofs of your condo project to be able to suggest the best solution. One solution involving interior work is to fasten 1- to 11/2-inch rigid foam insulation to the ceilings and cover the foam with new drywall. The same thing can also be done on the gable truss walls.
These dark lines are not mold, so rest easy. I hope this helps.
Q. My parents are getting on in age, but insist on staying in their house. I am concerned about their safety when they shower. I have given them a bath mat with suction cups that is very safe and I want to install safety bars in their fiberglass tub/shower unit. How do you install these bars in fiberglass? It seems to me that you can't screw the bars into the fiberglass as you would into wood.
A. Moen offers the SecureMount anchors for that very purpose. It's an oversize molly bolt-type anchor that's very easy to install. You'll need a 11/4-inch hole saw to drill the two holes needed to fasten each bar.
After you have located the area where you want to place the bars, apply masking tape to the fiberglass and draw a circle around the mounting brackets. Then mark the center of the holes to be drilled. Carefully drill the holes, using the slowest possible speed. When the holes are drilled, follow the installation instructions. You should be able to buy the SecureMount and accompanying safety bars in plumbing supply houses carrying Moen products.
Q. Are there any advantages or disadvantages in replacing basement windows with glass blocks? I know that the escape window can't be replaced with glass blocks. We do not have any problems in our finished basement but wanted to do this for more security.
A. I can't think of a reason why you can't do that. Security bars would be less expensive but not as attractive.
Q. My granddaughter's formula accidentally spilled onto my concrete patio, leaving a dark stain that I can't get out. Do you have any suggestions?
A. You haven't told me what you used to try to clean the stain. It is very difficult to remove this type of stain - most stains, actually - from concrete without affecting the overall look of the slab. Baby formula, having an acidic base, has probably etched the surface of the concrete and penetrated deeply. If you haven't tried it, you may want to wash the stained area with a solution made of one part fresh Clorox bleach to three parts water. This may lighten the stained area to some extent, but it can also make it more prominent next to the untreated areas.
If you cannot live with the stain, the ultimate solution is to have the concrete surface ground. You can end up with an exposed aggregate surface that should be sealed. Exposed aggregate means that the stones in the concrete are now showing, and, depending on your taste, it can be very attractive. Or the surface can be polished, after the grinding, to return to the original texture. If you are interested in that process, call a concrete company and ask them for names of people who do grinding.
Q. I have an old water-softener system that works well but is old and requires salt to be added to the tank periodically. This requires lugging heavy bags of salt to the basement as the salt empties. I saw a system several weeks ago that softens the water electronically, no salt involved. You mount the unit on the wall near the incoming water line, wrap the pipe with a wire lead from the unit and plug the unit in. It supposedly softens the water by some type of electric current that the water passes as it travels past the wrap. I believe this particular unit was called "Aqua Flow," and the Web site was easywater.com. Have you ever heard of these types of softeners, and do they work? I thought I might upgrade my system and wondered if this was a better system. It priced out at about $200 compared to $700 to $800 for the conventional type.
A. If it does not meet the National Sanitary Foundation standards, beware. You may want to check the NSF Web site, nsf.org, for proof of performance.
Q. I have a jet bathtub that is under 10 years old. As I get older, I find myself afraid of slippery conditions. Is there something I could do to make the bottom of the tub less slippery? If so, is this a simple fix, or should I have a specialized carpenter do this? I want to make sure it's done correctly so that slipping in the tub will be nonexistent.
A. The best way to accomplish this is to buy a netlike mat with many suction cups. I use one and find it very safe and secure. After showering, dry by hanging it over a safety bar or the curtain rod. You should be able to find it in stores that specialize in bath accessories, like Bed, Bath & Beyond. I would discourage you from using sticky decals on the bottom of the tub; they get messy and are difficult to remove as they disintegrate.
Q. About nine years ago, you inspected my house in Shelburne, Vt. I still live there and absolutely love the house! At the time of inspection, you said I would need a new roof in a few years. I'm now looking to replace my roof. It seems that the big difference is that metal/aluminum last longer. In one of your articles, you said they can crush decks, etc., due to the heavy snow coming off the roof at once. You also said that roof raking (which I have done) harms the asphalt shingles. Several people are pushing me toward metal/aluminum. One roofer told me that aluminum is lighter and less likely to rust. If I went that way, should the roof be put over the shingles or should they be removed first? Is it really loud when it rains? Most people I have asked love their roofs, but one friend said that the sound is so loud in the courthouse she works at in Maine that they need to stop court proceedings until the rain stops. Are they hotter or cooler than asphalt? Is there a difference between the narrow paneling and the wide?
A. Factory-coated galvanized metal is heavier than aluminum (also a metal), and it is unlikely that it will rust for many years. Dark colors will absorb the heat of the sun, regardless of the type of metal used, so there won't be much difference between either metal or dark shingles. Light-colored shingles will reflect the heat more.
Snow slides off metal roofs under most conditions, and that is what I referred to when I mentioned that it can crush decks that are not solidly built. Snow that slides off roofs becomes very heavy and hard-packed, and can be difficult to remove if it obstructs a doorway or if the deck needs to be cleared before the next snowfall adds to the weight. Either galvanized metal or aluminum should be screwed with special screws (Woodtite is one brand) and not be nailed. If the asphalt shingles are in reasonably good shape (not curling too much, none missing, etc.), the metal can be put over them. However, it is best to strap the metal. This will provide an air space under the metal that will help dissipate the heat buildup and lessen the noise from the rain. The negative side, if you object to it, is that this makes a very desirable place for bats to nest, but it will keep your deck free of mosquitoes while you enjoy it. The width of the roof panels is a matter of choice.
Reader tip
I wish you had suggested an environmentally friendly and inexpensive way to kill moss and weeds between pavers. A tea kettle of boiling water or straight vinegar will do the trick without all the repercussions of chemical poisoning. I happen to like the moss, so I pour directly on the weeds that might disturb the pavers and sometimes inadvertently kill the moss, too.
• 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 e-mail at henridemarne@gmavt.net.
© 2009, United Feature Syndicate Inc.