Solve basement moisture problem easily with dehumidifier
Q. My daughter lives in Shelburne, Vt. She has discovered many boxes in her basement storage room with mold near the bottom, but the walls and floor do not show any evidence of water infiltration. The boxes are a few inches above the floor on metal shelves. The door to this room is normally closed and registered a relative humidity of 70 percent when she discovered the problem; it also has a very bad odor. One long wall in the room is against the foundation, but all walls are covered with drywall and the foundation wall is insulated correctly, I believe. She has installed a dehumidifier and reduced the relative humidity to 50 percent, but we're wondering what has caused the problem and what is the best long-range solution.
A. Seventy percent relative humidity, or RH, in a closed basement is too high, and the actual RH near the floor is likely to be considerably higher as the temperature is lower. Assuming that the boxes are made of cardboard - a very porous material - it is not surprising that mold has developed. The best long-term solution is to use a dehumidifier in that room or, if your daughter uses one for the entire basement, to keep the door to the storage room open. It may also help to have a fan circulate the air in that room.
Q. My colonial was built in 1962, and when we moved into it in 2002 it had some settling and there were cracks in the foundation. We tuck-pointed the cracks in the brickwork and assumed we'd be fine. However, over the past six years the foundation has sunk further in two places. First, the outer wall of our attached garage. The outer brick wall is now bowed out, and the wall by the garage door has leaned about 1.5 inches (measured at the top). The other spot is in a back corner by a family room. The stair-step cracks in the brickwork have opened up again (since being tuck-pointed in 2002) and it seems to have sunk another one-half inch at least. It seems that the best move is underpinning to stabilize (if not raise) the foundation. I've found that there are at least two methods used.
One is called mud jacking, where a grout is injected beneath the foundation to densify the soil and potentially lift the foundation. The other is to use a pier and drive a pile down to dense soil or bedrock and then attach that to the foundation (thus bypassing the soft soil). The mud jacking appeals to me as a less-invasive approach; however, I am not sure how well it will work or how long it will last. Can you give any guidance as to the best (and most economical) way to at least stabilize the foundation?
A. Your first approach should be to contact a structural engineer to assess the situation. He or she may recommend a helical pier system that is easy to install and is generally done from outside.
Q. Answering to a waterproofing-basement question, you wrote: "If the walls are made of poured concrete, you may want to try to waterproof them with one of the coatings available in hardware and building supply stores." I would appreciate some additional information regarding your response since this is the first time I have seen you recommend waterproofing a basement. Our home was built in 1929 with a poured-concrete foundation. As you recommend, we addressed the grading and the gutters. This has greatly decreased the amount of white powder buildup on the basement walls. We did not use waterproofing because we thought this would cause more problems. After reading your recent article, we want to know if waterproofing on the inside basement walls is OK for a poured foundation, even one as old as ours. If so, is there a particular product that you recommend?
A. If I recall correctly, my suggestion to waterproof poured concrete walls was in answer to a mysterious water problem in a small bump-out workshop. It is generally safe to apply a waterproof or decorative coating on poured concrete foundations since they cannot store water, whereas hollow concrete or cinder blocks can and will if waterproofing is done from inside. Water stored within the cores can wreak havoc within the living quarters above. If your poured concrete foundation is in good shape - clean and not suffering from dusting - it should be safe to apply any waterproofing coating, but do you need it? If the goal is to make it prettier, use a cementitious paint or waterproofing compound that will not be affected by any moisture coming through the walls, as paint will, since concrete is somewhat porous. There are a number of good products on the market such as Super Thoroseal.
Q. Are you aware of any window manufacturer that makes an aluminum exterior, wood interior window with really high-efficiency glass? I have noticed an interesting trend in windows. The big guys, like Pella, Andersen and Marvin, who make very nice, very high-quality windows, offer glass that has only a .29 U factor/3.4 R value. However, there are a couple of manufacturers of vinyl windows, specifically Wellington of St. Louis Park, Minn., with a 7.7 R value window, and Gilkey who claims to have an R-10 window. Both use a form of Low-E, triple pane with Krypton gas.
Do you have any comments on these types of windows? Gilkey uses a center glass pane while Wellington uses a middle layer of film. It has to be a plastic film. Do these films have a short life? How long do they last? Do they yellow? Gilkey claims their hollow-core windows are just as energy efficient as wood or other foam-core vinyl windows. It seems that the ideal combination for energy efficiency would be the Gilkey or Wellington-type R-10 glass in a Marvin aluminum and wood frame. I am considering new windows for my home and I would like to install the highest efficiency windows possible and would also like to use a material that will hold up to the elements. I have concerns about how well vinyl tolerates sunlight. My Andersen windows are deteriorating on the sunny side of my house, and I should probably replace them.
A. Are your Andersen windows deteriorating from lack of timely maintenance? Attending to that now may save your windows and money as well. I have no personal experience with Wellington or Gilkey windows, so I can't be much help there. Just remember that claims are just that. If they can be verified by an independent source, then they can be relied upon. Keep in mind that any increase in the U-value of a window's glass must be weighed against the quality of the other components: Will they stand up to time? Will they hold up to the elements? Is their weatherstripping long-lasting and effective or will wind blow in around their frames and sashes? Do you insist on an aluminum exterior and wood interior, or would any maintenance-free exterior such AS vinyl or fiberglass be acceptable to you? Marvin and Andersen offer these finishes and there is no reason to believe that they will not last. My Andersen Terratone Perma-Shield casements are 30 years old and have not had any color-retention problems.
Q. We recently noticed a small hole that had been bored through the Sheetrock and into the framing inside our house. There was a little sawdust on the chair rail below it mixed in with the plaster dust. The hole is about 3/16 of an inch in diameter. What kind of insect would do this? It occurred in late October and we live in a wooded area of Vermont. What, if any, corrective measures should we take beyond just plastering the hole?
A. The insects could be carpenter ants. If you see any activity in the spring - the ants may have gone underground for the winter - try to catch a specimen and take it to the entomology department of your state university's Extension service or to a pest-management professional for identification. Either one should be able to advise you on control measures. Meanwhile, leave the hole open so you can catch a culprit and monitor the situation.
Q. Thanks again for your reply to another problem. Sure would like you answering another. We had Sears install a high-efficiency Carrier furnace in December of 2005. The installer improperly installed it, as he had to return five times to make corrections during that heating season. In the 2006 season, another technician came in for a tune up of the furnace and noticed the installer had failed to make some connections necessary to operate the furnace efficiently. During that season, we had two different technicians inspect the problem. They found more problems and corrected them. Now a tune up technician told us that Sears failed to install a flue (which we paid for) and that the new high-efficiency furnace could not carry the exhaust up through the vent into the shield and out the top of the chimney. Our other furnace was a lower efficiency one, installed in 1987. It failed when we tried to use it in December of 2005. A chimney-sweep technician inspected and said the furnace caused some breakaway of the pipe from the vent up to the chimney top and was causing the furnace to shut off. He cleaned out the debris and has recommended a new flue and that pipe that goes up the chimney, steel or aluminum. What happened, in your opinion, and what should we do?
A. You have had a series of service calls by several technicians, each finding some problem not mentioned or dealt with by previous service people. And all of that because of what appears to be a substandard installation by a Sears installer. Not only that, but Sears did not install the new flue you paid them for. You should get Sears to install the flue they owe you or refund you its cost and the installation fee. Find a competent heating contractor familiar with Carrier furnaces to get everything working as it should. Then you should present the bill from this contractor and all the others to Sears and demand payment. If they refuse, contact the consumer protection division of your state's Attorney's General office and send them all the information they need to advocate for you. If this does not resolve the case, and the sum is significant enough, you may want to contact an attorney to see what your options are. There is no excuse for such sloppy workmanship.
• Henri de Marne's column appears Sundays. He 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.
© 2008, United Feature Syndicate Inc.