Ask the Expert Question-and-Answer Archive

by Ron Joseph

Painting vs. Staining Cedar Shakes

Q. Our condominium association needs to decide on repainting (restaining) the cedar shingles of our building walls. We heard that painting will last longer than staining and thus be more cost efficient. Are there any concerns about painting the shakes rather than staining them? They are currently stained with a grey finish, but have to be restained ever so often.
Thank you very much.

A. There are advantages and disadvantages to each option. On the one hand, painting the cedar siding will protect the wood from degradation by sunlight. That is only true if the wood is properly primed and topcoated using a paint that has excellent sunlight resistance. If you decide to take this route you must paint all six sides of the siding, including the back. If you only paint those surfaces that are visible to the eye, atmospheric moisture will penetrate into the wood at the unpainted surfaces and migrate inward. Then on a hot day the moisture will want to evaporate from the hottest surface, which is usually the one facing the sun. Sufficient pressure can build up behind the paint to push it off. Hence the paint will start peeling and falling off.The next stage is for the exposed wood to expand on a moist day and then contract when the weather dries out. Eventually, the wood will crack and the cracks will extend to the surrounding intact paint. This cycle will continue ad infinitum. Hence maintenance repainting needs to be done on a regular basis; every few years. If you paint all six sides, especially the end grain of each siding plank, you will significantly lengthen the life of the painted wood.

If you choose to stain the wood, moisture will enter and leave whenever the weather changes and it should not be necessary to stain all six sides. A stain that has excellent UV protection can last for more than a year, but once again you will need to redo the job on a frequent basis. Staining will not necessarily prevent the wood from cracking if your weather fluctuates between moist and dry conditions.

In my opinion a properly done paint job will probably outlast staining. Before you start painting insure that the paint is compatible with the old stain.

Regards,

Ron Joseph