Sneaking up on the solution for crawlspace temperature problems

Q. We just bought a nice 37-year-old Dutch Colonial home. We have crawlspaces at both ends of the house (not sure if these rooms are additions). Our inspector told us to screen the inside openings to the basement in order to maintain the same temperature throughout the crawlspace and basement. One contractor told us to seal the crawlspace entrances, and another contractor told us to screen the entrances to the basement and put in an exhaust fan on the crawlspace window to drawl the damp air out. Which do you think would be best?

A. If the crawlspace floors are thoroughly covered with 6-mil plastic or are made of concrete, there is no need for any outside ventilation. Outside ventilation can actually be detrimental, as it introduces moist air from outside that is absorbed by all wood members, making the crawlspace atmosphere unhealthy. I know it flies in the face of the building codes, but they are often behind the times. In your case, you can leave the crawlspace openings to the full basement open but keep the crawlspace window closed year around. Whether you screen these openings is up to you, but there is no need to do so.

I have a problem with a $6,000 investment. I had some guy measure all windows and ordered custom-size windows. Each window is about one to 11/2 inches short of the opening of the original window. My windows were attached to Sheetrock and there was no stop. I have attached a couple of photographs of the windows from inside and outside. I am getting different suggestions.

•Install new siding to cover the windows, so no water leaks and no fear of mold.

•Replace all windows with the right size.

•Build a new frame around each window.

•Install a doorstop from inside to prevent draft, (this does not solve the outside problem).

I am totally confused. I do not want to put my house at risk for mold, which will be very expensive to fix and may be a great health hazard. Can you suggest a solution to save my investment or fix this problem?

A. I am sorry that you suffered from such a dumb mistake. This seems to be another case of incompetent people taking advantage of unsuspecting and trusting homeowners. Please only do business with reputable, long-established businesses with valid recommendations and references. A skilled carpenter can easily fix these errors by building a frame around the exterior and interior of the windows to seal them from the weather. He or she should then insulate the spaces between the windows and the structure with a low-expansion foam and finish them properly inside.

Learn from your experience and call upon a reputable general contractor to make the necessary repairs. If the cost is high, you may want to consult a lawyer to see if there is any recourse against the incompetent firm you dealt with or file a claim in small claims court.

The exhaust fan in our hallway bathroom doesn't seem to suck any air out of the bathroom. I put a single square sheet of toilet paper up to it and it just fell to the floor. The exhaust fan couldn't even attract the single square of very thin paper. Can you recommend a bathroom ventilator that sucks the moist air out? Ours is vented to the outside.

A. First, check to see if the vent from the fan to the outside is kinked, broken (as can happen to the flexible plastic piping) or full of water from condensate from a bent duct. The often-used flexible plastic piping is very flimsy and should be replaced with either metal or rigid plastic piping that runs with a slight slope from the fan to the outside. It is also possible that the fan is defective. Any well-known brand of bathroom fan should work well.

My raised ranch style house is 37 years old. A new roof was installed over the existing roof about 17 years ago. We now plan to remodel both bathrooms completely and install new exhaust fans. One of the bathrooms has an existing fan vented through the soffit that is working quite well, but needs to be upgraded. Both bathrooms have windows. The roof slopes down on all sides to meet the shingles. I believe it is called a hip roof. There is very little room in the attic above the bathrooms, probable less than 2 feet. My contractor feels it would be better to vent the fans through the soffit because of the age of the roof. He said if it was about 8 years or less, he would feel differently. I am reluctant to cause any problems with the roof. He is willing to vent the fans through the roof if that is what we want. What is your opinion?

A. You haven't told me where you live, so I am not able to advise you because your specific climate has a lot to do with my answer. Where is the other bathroom fan venting now? Your contractor is wise not to want to touch your 17-year-old roof, which may or may not last another few years; there are so many premature shingle failures still going on that it is mind-boggling! You'd think that, by now, the shingle manufacturers would have gotten their act together after the problems of 20 years or so ago.

Although I am not in favor of venting any fans through vented soffits, and even less in favor of venting them through roofs, if your hip roof has no ventilation, venting through the soffit is OK as long as it has not affected the paint and the wood. But you seem to have few choices. Bathroom fans have a mixed history: They can be energy wasters but they can also provide benefits. If local building codes do not require bathroom fans, as long as you have windows in both bathrooms, you do have the choice of not installing them; simply open windows after showers and use one of the many odor-killers for other purposes.

Correction: Several readers have advised me that CertainTeed asphalt roof shingles also have a premature failure problem, and there are class action suits against them in several states. The contractors who have told me they switched to CertainTeed in lieu of IKO shingles because of the many premature failures of the latter brand they have experienced, are obviously not aware of it. I haven't heard of problems with BP, and that is what we installed on our roof recently, following the failure of the 25-year IKO shingles that were put on 14 years ago. Sorry for the misinformation.

• 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.