Yes, you can put these panels on the outside. They are made from a closed cell polyurethane so they won't absorb any water, will not rot and are weatherproof. They have a UV protective paint to help with sun fading as well. Please see attached photo of a recent installation. Thank You!

I was interested in buying these, how do you cut the ends that protrude if you want a flush end? Do you use a regular circular saw?

You can cut them off and make a straight cut with a circular saw or chop saw. Then use our grout and paint to go over any exposed urethane. Also if needed you can use a trim or molding to butt against the cut to create a cleaner look.

Yes...most projects are for exterior.

Yes...100%