I followed a referral to this forum but couldn't see where the same question was asked here. We just enclosed a patio and want to run engineered wood from the kitchen through to this new room. However, we live in an area where there is a lot of ground movement and I'm concerned about the flooring across the joint between the two rooms. The patio was added several years ago and was tied to the house slab by drilling holes for the patio rebar but it's still a separate pour. There was brick on the house, so the brick ledge needs to be filled and I figure leveler will need to be added there after that.

Next to the kitchen is a den that already has engineered wood, running parallel to the kitchen.

Should we run the new flooring the same direction as the den, which runs it across the joint between the rooms, or run it perpendicular to the den but parallel to the joint between the two slabs, and use a transition piece between the kitchen and new room, and another transition piece between the kitchen and den?

I hope this makes sense. Thanks!

You can buy crack monitors for slabs here http://www.testmark.net/c-4-p-135.html but that may take awhile to check, better to watch over a couple seasons. Floating floors are great for potential issues like that as the floor is not affected.

Yes, that would be a good idea. Are there any floating floors that don't sound like loose linoleum when walking on it?

It's never going to sound as good as glued or fastened, but the underlayment is the key. Get a quality underlayment, not a box store underlayment.

Can you suggest the name of a quality underlayment so I can see what it looks like? Our den floor was glued down.

If an underlayment is used, does the floor still have to be completely flat? Our slab isn't perfectly flat in the kitchen. When barefoot, I can feel a drop off at one end. It feels like there is probably a low area right that extends from one area of the kitchen through the laundry room and into a bathroom where I can feel the level get higher again.

I prefer Sound Solutions, but Floor Muffler is just as good. But FM says to run the underlayment perpendicular to the floor, I find that unreasonable. Sound Solutions comes in 450 sf rolls and 100 sf rolls.

Yes, the floor needs to be flat and if gluing the T&G I feel it should be better than the standard of 3/16 in 10ft.

We've been visiting flooring showrooms and the consensus is that no underlayment should be used with a glued down engineered wood. Maybe that's just this area (Central TX). We wanted to see if we could find any wood that blended with our old wood, and found some at Floors and Decor. It's a Bruce hickory, engineered, 3/8". But now I've been reading so many complaints about Bruce that I think we should probably keep looking. Our old flooring has been discontinued, but a local store ordered a few boxes for a repair last year. I wonder what the odds are of being able to order 320 more sq ft of it?

I've always been o.k. with Bruce, and brought up on it...don't know what the hubbub is with some guys Just about every installer runs into a batch of wood, they don't like. Doesn't necessarily mean the manufacturer and their whole product line should be questionable.

Bruce has been milling up more 3/8 engineered. I've had some minor issues with their wood but nothing I could not cull out effectively. Nothing as compared to other liquidator/foreign manufacturers. I try to get my clients to by American made. Plenty of them out there too.

Back to the floor over old and new. One good method is to tie in the old and new with rebar and epoxy, epoxy the joint as well. Grind out joint and grind out ledge to help flatten transition area, make cuts where the rebar in going, about 1 foot lengths couple inches deep across the new and old section.Epoxy them in and the joint, level area out. Then use Bostiks MVP4 over top, then use Bostiks Best adhesive. MVP4 helps bridge cracks anyway, and then you have the adhesive on top.