Installation Methods (floating)

Why is the float method specific to particular styles of flooring?

Why not glue tongue and groove solid hardwood together and float it over concrete? I only see mention of this method for engineered hardwood but I can't think of the reason.

I know solid wood flooring expands and contracts more than engineered, but the wood is free to expand just as it is with nail-down or any other method.

Also, with nail-down method for solid flooring, wouldn't the expanding wood push up the nails? I don't see how this is more effective than a floating installation.

 

There are floating solid wood floors. A company named Junkers(I think they were just bought by another company, though) has a floating solid wood floor.

Glueing solid will split at the glue joints from each individual board swelling and shrinking with moisture changes.

 

As the board contracts, will it not pull the board next to it closer and keep the glue joint intact? I imagine the whole floor shrinking and expanding as a unit.

And if the expansion/contraction is strong enough to break glue joints, then isn't it also strong enough to push up nails?

 

I think I read something on NOFMA about attaching laying down one layer of subfloor type plywood ( which is not attached to concrete) and then another above that at a 45 angle nailed together. Then ontop of that nailing the solid wood to the "subfloor" in the normal fashion. So this would add about 2" to the floor. There is proably a vapor barrior in there too. I just read something I thought was interesting and related to what you were asking. I don't know when the approach is used. So this is a 2" floating floor if I understood what I read correctly.

 

There are so many methods. It becomes very confusing when reasons are not included. I could come up with a method that sandwiches 13 different layers of wood and plastic together, but why?

I was hoping that experienced installers could explain the reasons behind certain methods, but it seems anytime I ask somebody they tell me what needs to be done but they can't explain why it needs to be done that way. I don't like to blindly follow the herd, so I'm still hoping someone can explain things.

I would love to have time to setup a few different closed box tests using various methods with the wood I'm interested in, but I don't have the time.

 

I think this was the expert answer you were looking for.

http://www.nofma.org/
Is an authority on solid oak flooring. You can find answers to many of your questions in there in pulblications such as "Behavior of Flooring and Moisture" and "Keys to Wood Flooring Performance". I am sorry I was not the expert you were looking for but I merely intended to give you information that would lead you the answers you seek.

 

Sure but it doesn't make sense given that the boards should swell as a group, not as individual units. They're made of the same wood, same density, same moisture exposure, etc.

Thanks though. I think I'll give up and maybe one day conduct my own experiments to satisfy my curiosity. In the meantime I'll just get engineered wood and have it professionally installed.

Thanks for the link. I'll check it out and see if I can find satisfactory answers. I'm probably being too analytical.

 

Some good information at that site. Still heavy on "what to do" but not much on "why it has to be this way".

I did find out that the wood will typically only stretch 0.1% along the length of the board. This is for extreme 0% to 28% humidity change. That shouldn't be enough to trouble the glue joints. In other directions it's as much 15% change for the the theoretical maximum humidity change, but typically it will be about 1" for the whole floor 13' wide. As mentioned above, if the floor is floating, I don't see a problem with it expanding by 1". I do wonder how the nails stay in place for nail down installations. Unless the subfloor is also expaning at the same rate, but not likely since it's a different type of wood.

 

Average board density, is not the number each board will automatically have.

Try it, and tell us what happens.

Just think, even nailed down floors buckle.

Even nailed down floors gap.

Look what happened here when the finish side bonded(glued) the edges.

http://www.thefloorpro.com/community/attachments/flooring-inspection-services/1933d1173152405-splitting-wood-dscn2828-jpg

 

I can't access the image even after registering.

But you confirmed my point that even nailed down floors buckle and gap. So how is nail-down installation any more reliable than floating?

I think it has more to do with the quality of the installation regardless of the METHOD used.

Plus of course the site variables. Old concrete vs fresh concrete, seasonal moisture variations at the site, subfloor preparation, proper glue, etc.

Of course I can't verify any of this unless I waste a whole bunch of time setting up test boxes with various installation styles, and then simulate humidity changes. I'm just going to find the best engineered hardwood I can find that actually looks decent, and have it professionally installed.

 

Least with laminate floating floors you can replace planks without to much of a headache. It would tear the wood to pieces if it was nailed or glued. My .02 cents.

 

I think the solid and engineered hardwoods usually claim about 8 refinishes.
Nobody talks about replacing planks. Hopefully nothing that drastic happens that a plank needs to be completely replaced (given a proper installation).

 

Oh I forgot, that link is in the contractors part of the forum.

Ask your question there in the consumer forums, after your registration is confirmed, if you want more then one opinion.

 

A glue joint would be the strongest part of a solid wood floor, due to that when the floor expands and especially when it contracts, the glue joint would hold and the wood would splinter next to it, this is why you dont glue real wood.

 

I also agree with Mike.

My understanding is that PVAC wood glues like Titebond actually provide a stronger connection at the glued joint than the wood itself. Because of the possibility of the solid hardwoods contracting or swelling the boards have the potential to crack or split on the board and not swell or contract at the joint. I also do not believe that the floor would expand and contract as a single unit as wood grain may vary too much from board to board in a real wood application. Would it expand or contract enough to cause problems? Depends on the enviornment I guess.

The main reason that flooring companies and installers do not suggest or use the glued tongue and groove floating installation in a solid hardwood is due to the manufacturers warranty. Any failures in the flooring install not covered by the manufacturer will void any warranty. There is a reason that almost all or all of the manufacturers of solid hardwoods do not warranty or suggest this type of install.

I am not saying that it can't be done. I am quite sure it could be done, but you had best hope that the conditions within the home stay relatively constant with good climate / humidy control. By all means do it yourself and let us know how it goes.

 

When it contracts the glue will hold and splinter the board next to it?

I would think that if one board contracts, it will pull the others inward as necessary. When it expands, it will push the other boards out with it. If all the boards expand, they'll all move outward towards the expansion gaps.

Right?

And as mentioned above, if things are moving around so much, then I'm sure nails are going to be pushed up, and/or boards will have the same problem of not being able to expand and splintering.

I still don't see how gluing is any worse than nailing down in an environment where there is so much movement.

I'm not going to try it though. If the manufacturers don't want to glue and fload solid wood boards, then so be it.

Engineered boards with all their cross graining and various other attempts at strain control will probably end up on my floor. Professionally installed. I'll just stay out of it and try not to think about it. Now if I can't find an engineered board with the wood that I want then I'll have a problem and I may end up forced to find things out the hard way (typical problem for me as you may have guessed).