Question about Crown Moulding

It is hard to say about the cause. There are techniques that can reduce problems with expansion and contraction.

As for filling the joints, I would not use silicone. It tends to not work well for a number of reasons including holding paint and problems sanding it. Use painter's calk.

is the molding painted? if so, you can use a paintable latex caulk such as "big stretch" and paint over it. silicone should not be used since it can't be painted over. silicone is used as a sealant, not as a painter's caulk. the big box stores are very poor places to get advice. if the gap is not painted (the molding is natural wood), then you are stuck with using wood putty that remains flexible.(use a non-drying putty such as "color putty" and test it out to see that you have a good color match) if there is a gap between natural wood and a painted wall, you can put painter's tape on the wood, caulk with paintable latex caulk, touch up the paint, and pull the tape.

Don't use silicone. It can't be painted. What you want is "Elastomeric" caulk. Ask the paint guy at Home Depot, or better yet, a real paint store.

The brand I use is "DAP Premium Elastomeric Latex Sealant". I've never had a problem with cracking on baseboards nor crown mouldng.

Thanks to all who responded, you've been very helpful.

Cheri

All wood moves. The molding should have been coped such so that the visibility of the cracks are minimal. If your molding is painted use caulk that can be painted. I'm not sure if silicone caulk can be painted.

The caulk being referenced, hopefully, is siliconized acrylic latex caulk. This is NOT the same as silicone. Go to Sherwin-Williams and buy some 1100A caulk. It is the caulk spec'd by the Sherwin-Williams techs for replacing other caulks that have failed (like the colored caulks). They do offer a better caulk, but who needs anything better than 55 year caulk?

"Buck Turgidson" wrote in news:xfpIg.7534$Tl4.2154@dukeread06:

I would agree one of the betterDAP's (not DAP painters caulk) is a better solution.

Also, various companies have made paintable silicone for some time now, including DAP: