Q. I live in central New Hampshire in a 1½-story Cape built in 1986. It’s a solidly built house but poorly insulated. On the coldest winter nights, the house will occasionally emit a loud (and scary) bang. I’m guessing that this is the wood contracting as the temperature drops. The noise seems to be coming mostly from the roof and the deck. I’m still not used to these “explosions’’ even after living here for 12 years. Are these contractions compromising the structural integrity of the house? Would insulation help? Is this normal?

JAY A., Canterbury, N.H.

A. Terrifying, right? Your house is definitely talking to you, and it’s telling you that it doesn’t like the cold. Basically, what is occurring is thermal expansion and contraction, and it’s harmless. Because wood is porous, its contracting is accentuated because the winter air dries out all of the moisture.

Sometimes you may hear wood pop, other times it could be the PVC pipes doing it. Cold pipes often do this when warm or hot water runs through them. Sheet metal, like HVAC ductwork, can also pop when warming up. This is often called “oil canning.’’

Q. I live in a place with 100-plus-year-old double-hung windows. There are two small windows that are difficult to open and close (especially with a bad shoulder and arthritis) because I have to reach over the sink. The way I have to torque my body to operate them does not give me enough stability to put any power behind the effort. They are about 18-by-36 inches.

Is there a way to use the existing antique window components to create casement windows? I love the look of the existing windows with their old wavy glass and their four-over-one pane design. I don’t want modern-looking casement windows that look flat and devoid of character. Could a genius carpenter fit the existing components into a casement, retrofitting the opening so I can operate them with a crank? I am not afraid to spend a bit of money on this project.

A.L.

A. Unfortunately, you won’t find anyone willing to take those old windows and convert them into casements. You can, however, replace them with new casement windows that look like your old ones. Alternatively, lubricate the window jamb sides with wax, and install window pulls, or sash lifts. Window pulls screw into the bottom rail and give you better leverage to lift the window. They come in a variety of finishes.

Q. We have forced-air heat, and the humidity gets very low in the winter. At my wife’s insistence, I am using a large humidifier in our bedroom. When I inspected the unheated attic above our bedroom, however, I found ice crystals on the uninsulated sidewall sheathing. Is this likely to cause mold or rot wood? If so, how do I raise the humidity without damaging the attic?

ED

A. Yes, mold will grow over time. You need to seal off all air leaks, add more or better insulation to the attic floor, and improve your attic ventilation.

Rob Robillard is a general contractor, carpenter, editor of AConcordCarpenter.com, and principal of a carpentry and renovation business. Send your questions to homerepair@globe.com or tweet them to @robertrobillard.