Question:
I purchased your article on installing hardwood floor on concrete and it really did not answer my question. I want to install a 3′ by 5′ area of solid plank wood floor that will be surrounded by carpeting. This is in a 1 year old home that I have performed a moisture test on for the past 6 months. Since this is such a small area I was hoping to get away with a glue down install to closer match the carpet. The insert that I am installing is a computer generated design that will have only a couple 3′ lengths to it. Should I seal the concrete? I have read about gluing down a plastic sheet? Should I glue a wood border or should I secure a border with screws? It will have nail in carpet tack strips around the insert. Any ideas?
Thanks,
Brad
Answer:
Dear Brad
Thanks for purchasing the article, but it really did address your situation, in a way. In the third to last paragraph, I talked about gluing down solid wood floor. And the very worst choice for installing wood plank floor (I assume you are using the term plank floor meaning the boards are 4″ and wider) would be to glue it directly to the concrete. But if you must do something unorthodox go ahead. The good thing is that there are only a few boards that are 3 feet long. But do all the boards and designs have a flat bottom ? That would be essential for the glue to get a good grab. And boards that are quarter sawn will have a better chance to resist warping with this poor installation method.
If you must glue the floor down I would recommend the DriTac 7500 urethane adhesive. This glue is waterproof in itself, so no sealers are needed. In fact a concrete sealer or plastic will interfere with the glue. You could use Tapcon concrete screws for some of the long planks or boards that just will not stay in place before the glue dries. Dry lay the whole pattern and see how well it hold together. If you find you need to screw a few of the ends down, you could counterbore and screw and cover the screw holes with a wood plug. This assumes that this is an unfinished floor, and that cutting the plugs flush and sanding and finishing the are will be part of the job.
But some of the wide boards may still swell and shrink seasonally and even break off this glue layer. So keep this area well coated with oil modified polyurethane, and the house within a narrow humidity range. But to be frank, Brad, I would not do such an installation. If all you want to do is “get away with it” go ahead. I cannot advocate unorthodox methods in my articles, nor address all the possible variations to these installations. But I do appreciate the feedback, and we will in the future provide an easier to reach email address for you wonderful folk who purchased my articles.
As always your Most humble servant, Joseph, the Wood Floor Doctor.