How much does wood crown move?

[Brian H]

Hello,

I'm having a hard time choosing between installing MDF or wood (pine) crown molding in my home. I found some beautiful pine crown at a local lumber yard, but everything I have read says that wood will move and crack the joints/paint and that your have to cope the inside corners instead of doing miters.

I know the expansion/contraction of the wall is due to temp/humidity fluctuations. I live in the central valley in Northern California. Winter temps get to the low 40's with humidity being 100% and summer can get in the mid 100's with 0% humidity.

Should I be concerned with installing the pine? Thanks for your suggestions.

 

[Luzzy]

All wood moves, even MDF. In my own house I installed 6" cherry crown with stain and poly finish in the master bedroom and matching 6" painted poplar in all other rooms and hallways . Since it was big crown , I ripped plywood slightly under the size of the back of the crown (1/4" light) and with the appropriate bevels on top and bottom . Then I glued(pl 400) and nailed the rips (into studs and ceiling joists) and ran my crown.

I took the time to seal the copes and any miters I had in the run with paint or clear . Seven years later I've seen almost no movement. Like any wood, allow it to acclimate to where its being installed and then seal all your cuts as you install if you can. I've installed thousands of feet of crown and can tell you that having a solid nailer and taking the time to seal your cuts does make a difference.