"He also told me to turn off the water supply to the fridge when we are away for more than a week.
"We have had no problems since."
Question: We had a regular, electric-powered fan in our previous home and the idea of the solar fan appealed to me. However, all the solar fans I saw were lacking a feature that the man who installed our electric fan said was very important: a firestat, to detect unusually high heat and shut off the fan in case of a fire.
That seems like a very necessary safety feature and I was surprised that I couldn't find a solar fan that offered it.
Answer: A quick check on the Internet found one by Ventamatic at www.bvc.com/solarvent.html. A firestat (which Google tried to search as "fire station") will shut system operations down when it senses that the temperature has gone above a preset level.
Q: I have a basement foundation of fieldstone. The house dates to 1835 or thereabouts. You mentioned that this basement construction made use of "Irish" plaster.
Can this fieldstone wall be sealed with Drylok or some other treatment?
A: I wouldn't do it. Someone once told me that the Irish plaster was designed to allow air exchange and preventing it will cause the plaster and stone pointing to crumble over time.
Q: I have a summer home at the Jersey Shore. The home is about three years old and six feet off the ground. The air-conditioning and heating ducts run under the house and are not insulated.
This space under the house is cold when the AC is on and warm in the winter. We were told we do not need to have this duct work insulated.
A: Without insulation, you are wasting a lot of money. Duct insulation comes in 1- and 2-inch thicknesses. Get the thicker material, especially if your ducts are rectangular; 2-inch wrap cuts losses by about one-third more than 1-inch material.
You'll also need several rolls of duct tape to seal all duct joints before you insulate.
Insulating the duct work prevents it from sweating in the summer when the cold air hits the humid. I had that problem in the basement of my house until I insulated it and also installed a dehumidifier.
More reader advice, from Dick McCormick, concerning the cause and resolution of a bathroom odor:
"I had a similar odor that I traced to a clogged bathroom vent pipe that exits through the roof over the bathroom. Each time the toilet flushed, a gurgling sound emitted from the tub drain.
"The clogged vent resulted in the water seal in the trap being drawn out with the flush (hence the gurgling sound), leaving an empty tub trap. The resulting loss of a water seal allowed sewer gas to enter the bathroom through the tub trap.
"In my case, the clog was a collection of rust particles and scale that had accumulated over many years having flaked off from the inside of the two-inch steel vent pipe wall.
"This eventually formed a solid plug in a 90-degree 'L' under the bathroom floor. Clearing this plug solved the problem.
"Another cause for a clogged vent is the accumulation of nesting materials in the vent where it protrudes above the roof.
"In any event, a clear and functioning vent is essential in plumbing systems to provide proper drainage and flushing of utilities."
Questions? E-mail Alan J. Heavens at firstname.lastname@example.org or write him at The Inquirer, Box 8263, Philadelphia 19101. Volume prohibits individual replies.