tile on a peeling wood windowsill
I have an enclosed porch with peeling windowsills due to moisture from plant pots. I found matted travertine mosaic tile strips at a bargain and want to put them on the sills. What kind of barrier do I need on top of the wood under the mud? Will a good sanding and a fresh coat of Kilz do it or do I need some sort of thin membrane? The end of the travertine is finished so I do not plan on using a bullnose edge. Thanks in advance.