Yes, Carpenter Bees will use this, and no, they won’t harm it. I’ve never had a Carpenter Bee chew into my blocks in another style house that I have. Mason Bees are “Gregarious Bees”, they get along with and coexist well with other native bees that will use this box....so it’s all good!
We read that it should be installed on early spring, facing east.ours faces SE. we live in NE Ohio, and have had a cold, rainy spring that still persists. If your spring has been like ours, I would say, get it installed by the first of a June.
There is the option for the size of the product to pick the single or double bee house.