I need to install a 30" oak threshold/saddle in my kitchen. I pre-drilled a hole and was going to nail it down with finished nail, but to my surprise the existing vinyl tiles were glued to a concrete base I believe. I do not see anything else under the tiles. I can't think of how I can attach it to the floor without going through concrete....I have thought of Liquid nails or something like that. any other suggestions please?