Ask the Carpenter: Is this chimney falling down?

Ask the Expert Home Improvement
A contractor used caulk here to close up a gap between the siding and the chimney. Handout

Q. Late last fall, I noticed that people were walking past my driveway and pointing. I’m not sure if they were pointing at my chimney, but I noticed a gap between it and the siding. The gap was large enough, maybe an inch in spots, that I was very worried, especially given that I’d seen quite a few ants in my home that summer. I hired a contractor to fill the gaps on each side of the chimney with caulk and cover it with rigid plastic. When I asked his advice on how to find out what was causing the gap, he said it would involve taking off the aluminum siding — at great expense. He said my best bet would be “to sell the house.’’

That winter I had a company inspect and clean the chimney, which received a clean bill of health, so I was comfortable lighting a fire in my fireplace. When the weather was a bit warmer in March, they came back and coated it with weatherproofing, and one of the workers said it didn’t look as if the chimney was tied in properly. Inside the house, there is some separation between the ceiling and wall on either side of the chimney, less than an eighth of an inch.

The house was built in the 1950s, and I have lived here for more than 20 years. I’m in my 60s and don’t know whether I will stay here, but I would like to know what’s wrong and how much it would cost to fix it.


A. It sure sounds as if the chimney is pulling away from the house, which is a structural issue. A leaning chimney can result in falling bricks, water and bug infiltration, and combustible gases leaking into your home if the liner is cracked.

The temporary fixes you mentioned are just that — temporary — and only mask the true problem.

If you have access to the attic, see whether the chimney is centered in its framed opening. If it’s putting more pressure on one side, then it is leaning.

My guess is that the chimney footing (foundation) has settled, failed, or is too small. It needs to be at least 1 foot thick and should extend 6 inches past the chimney on all sides. Anything smaller is more likely to collapse. Check for settling cracks as well.

I suggest that you contact a chimney repair company and a structural engineer on what needs to be done and the cost. There are ways of stabilizing and straightening leaning chimneys without dismantling them.


Q. The windows on the front of my house get a lot of heat from the afternoon sun, and the interior pine trim and stain take a beating. When I replace the windows, what do you suggest for an interior trim material that will be low maintenance and hold up well in the sun.


A. If sunlight is an issue, you should be looking at the glass. I recommend windows with low-emissivity (low-E) glass. Consider using a 3M sun-control ultraviolet film to reduce heat and fading caused by direct sun. These films can help you lower energy costs, eliminate hot spots, reduce glare, and protect carpet and furniture from fading. Many of these films reduce up to 78 percent of the sun’s heat, evenly disperse natural light, reduce eye strain, and block up to 99 percent of harmful ultraviolet rays.

Rob Robillard is a general contractor, carpenter, editor of, and principal of a carpentry and renovation business. Send your questions to or tweet them to @robertrobillard. Subscribe to our free real estate newsletter at