Hey folks,
Why does my local flooring expert at HD say that in order to float a wood floor you have to use the extra wide (6″ I think) boards for such a production? I have access to an old house being torn down with lots of original oak floor thin planks that I would like to use in my current house. However, since the current house is a concrete slab, I would much prefer to float these planks rather than glue them to the concrete. It will make any other future remodel job much easier. What would happen if I float the thinner planks?
Grumpy
Replies
First of all there's no such thing as an expert in anything at any HD.
Floating floors are typically engineered wood panels or sections that are extremely stable and designed to be installed over a variety of substrates.
Simply gluing solid wood strips together will not a stable floor make. (regardless of the size)
In a perfect world, with a perfect vapor barrier under your perfectly dry slab, gluing strips of perfectly climatized hardwood in a reasonably sized room in a perfectly stable environment MAY work in your favor.
Who knows.
Gabe
I actually thought about putting quotes around "expert", but I suppose those guys know more than I do, so I kept my comment to myself. As for the wood, what do you suppose would actually happen if I did float the thin strips, assuming an imperfect world. What would moisture do to them that it wouldn't do to the engineered planks?
If the moisture was sufficient, the wood would cup and crack easier. In the case of engineered wood the bottom 3/4 is essentially plywood with kerf cuts and as such is much more resistant to movement and is therefore more stable.
As discussed many times before, start by testing the moisture level of your substrate, using the 12" x 12" poly duct taped to the concrete trick. If water beads within the 24 hour test period, you will have problems installing any wood products without first addressing the moisture problem.
In the event of a moisture problem, a layer of poly over the concrete, (making sure to tape the edges and overlaps), sleepers and then the wood strips would stand a better chance.
Gabe
Between you and John Sprung, it sounds like moisture is the issue. If I put the poly down like you said and assuming that solved any moisture problems, are there any other reasons why I couldn't just glue the thin planks together. By thin I mean width. The thickness of each one is around 3/4 inch solid. No engineering here.
The moisture problem isn't just moisture from the slab. That is merely the biggest problem you might have. If your slab is bone dry, than you will still have relative humidity swings, which will cause the wood floor to move. Your proposed method will not restrain your boards sufficiently, so they will do what they want to.
As Gabe said, if you can control the humidity, and the boards are perfectly acclimated, then you'll be okay. Unfortunately, your not likely to achieve that state.
Jon Blakemore
Putting the poly down will not "solve" the moisture problem, it will only give a layer of protection. As Jon pointed out, you still have a humidity problem. By installing the poly and laying down sleepers to give a space between the wood and concrete to prevent trapping moisture you still have to control the humidity with dehumidification.
The main problem with your plan, forgetting about moisture for a bit, is that you will be building a singular sheet of wood over your floor area and when it shrinks and expands will crack all to hell.
Nail the strips down and each one will move independently and will not be noticeble unless of course you have a major moisture problem, then they will cup all to hell.
Without beating the moisture issue to death, it still cannot be overlooked. Your plan simply accentuates the issue.
Gabe.
Old thin oak -- how big is it? In my place (1926), the stuff is about 5/16" thick by about 1 1/2", and it's t&g. It was intended to be nailed thru the tongue to wood subfloor. They didn't do slabs in those days. To put it over a slab, I think you'd probably need to start with a layer of something to nail into, like plywood or OSB. But first you have to consider the issue of moisture from the slab.
-- J.S.