Why Do My Wall Trim and My Ceiling Spread Apart When It's Cold?

Cause

• During cold weather, the air in the home typically is drier than it is in the summer. This means that the water that is in the wood rim is lost to the air and, because of this, the wood contracts. As the wood contracts, it pulls back from the ceiling, causing the gaps. Depending on how dry the air gets, the gap could be small or large. In many cases, the trim will swell again in the humidity of the summer, closing the gap automatically.

Prevention

• When you are hanging new trim and you want to prevent gaps from happening, install the trim in the winter, when it will be at its smallest. Similarly, leave the trim in the room where it is going to be installed for anywhere from two days to a week, allowing it to expand or contract as necessary.

Solution

• If you are tired of seeing the gap and you do not wish to wait for the summer’s humidity to get rid of it for you, use a phenolic vinyl caulking compound to fill it. Squirt a small bead into the gap, and press the trim close to the ceiling to ensure that it holds. Before the caulk sets, scrape off excess caulk with a putty knife and wipe away oily residue. This type of caulking expands and contracts with the house, allowing the fix to be a permanent one.

Warning

• Do not use spackle or wood filler to fill the gaps. These materials are rigid, and as the wood expands and contracts, it will put small cracks into the filler. This leads to cracks that can look as bad as the gap did before.