Ask the Remodeler: Switch to fiberglass door to stop basement flooding

Q. My outside cellar door lets in too much water. We always got water in the cellar, but it was at a river point. I had a dry well dug and replaced the cellar door. Apparently, the door was built with unaged wood, and it shrank. I tried to fill with wood filler, but it kept shrinking and skewed the door. Now, I can barely bolt it closed. Water still comes in under the door. I think I need some kind of threshold or something to keep the water from running under the door; there is weather stripping, but it does not work well enough. I know I need to get someone to align the door, but how can I keep the water out? The ground slants toward the door, there isn’t a lot I can do about that. My home is 140 years old.

Gayle, Wakefield

Based on the pictures I have seen, I don’t think I would spend any more time trying to repair or remake that wood door. I would replace it. What we have done before and are recommending to clients when installing new basement doors is to first build a curb. Ideally with formed concrete but cement bricks and mortar will work as well. Next, install an exterior grade fiberglass entry door with an aluminum threshold sealed to the curb with silicone. The curb will allow some water to build up in extremely heavy rains, but it will not get into the basement. The fiberglass door will not swell and contract like an all-wood door, making it more stable. To take things a step further, you could also cut a hole in the concrete pad outside the door. Then dig a sump hole and fill it with stone and repour concrete with a drain installed in it. This would act as a small drywell and hopefully prevent water from pooling just outside the new basement door.

Reader feedback

All are welcome to send comments and questions at [email protected]. Here’s one:

Thank you for your April 14 column about spotting a problem roof (Ask the Remodeler: How home buyers can spot a problem roof). I would, however, amend your comment about adequate insulation keeping warm, moist air in the living area. Insulation does not stop air — air-sealing every penetration into the attic such as wall-top plates, electrical, plumbing, and HVAC chases is how the convection into the attic is stopped. Insulation on its own is just an air filter. Thank you.

M.

Response from Mark Philben:Thank you for your response regarding insulation/air sealing in attic areas; I agree with you. While adequate insulation is very important, you are correct that in addition to that, one needs to make sure that other sources of air leakage are sealed off. All the various utilities that you mentioned could come into play, including plumbing, electrical, and HVAC. Often these are air-sealed where they penetrate into the attic and that can add up. Your comments also reminded me of an important point when insulating attics that I had not mentioned: recessed lights. Many older and not-so-old homes have recessed lights that do NOT have what’s called an IC — insulation contact —housing. If they do not have that kind of housing and insulation is simply piled up against them, this could pose a fire hazard. That is an important point to ask your contractor about if you are considering adding insulation. Homes are complicated systems and all the parts and pieces have to work together to live in them safely and comfortably.

Mark Philben is the project development manager at Charlie Allen Renovations in Cambridge. Send your questions to [email protected]. Questions are subject to editing. Subscribe to the Globe’s free real estate newsletter — our weekly digest on buying, renting, selling, design, and more — at Boston.com/address-newsletter. Follow us on X @globehomes.