I just had 5" Anderson Applachain engineered hardwoods installed.....floating, over concrete slab. I'm not sure if this is just a 'floating' thing over using an actual glue down method, but when we walk on the floor, I can actually see the floor move. Not just with me or my husband walking on it, but even with my toddler on it. Does this sound like something that's just normal, or is this caused by them not prepping the subfloor correctly?

They spread float on the floor, then used the foam sheets on top of that prior to installing the hardwood.

Also....there are gaps randomly throughout the floor.....not huge gaps, but enough for me to see the joints/bottom layers of the wood. Some of these gaps are at the ends of the planks and some of them are at the sides of the planks. How much is too much gap?

Thanks! I don't want to be picky....but I want it right too, so thanks for any info you guys want to throw my way!

Movement/flex, will cause the floor to eventually separate/come apart.

It should not flex, if the floor prep was done up to the manufacturers specifications.

Gaps are just sloppy workmanship! Did they use strap clamps, to clamp their glued work together, while they could get the blue masking tape tight, keeping the installation gap free.

Thanks for the reply.....

So...I shouldn't see any 'flex' at all when someone walks on the floor...correct?? Or say, when we set funiture down on it....should I see flex then?

And, to answer your question, no...they didn't use any straps while taping. And, they only used tape when they would get to an edge where they would need to stop while they did something in another area.

GOOD LUCK WITH YOUR INSTALL ...DOESNT SOUND GOOD . I HAVE BEEN FORCED BY MY FLOOR COMPANY TO HIRE AN INDEPENDENT CERTIFIED FLOOR INSPECTOR. THEY GET AROUND 500 BUCKS TO COME TO YOUR HOME . HERES THE TOLL FREE NUMBER TO REACH THEM .
IT IS THE NATIONAL WOOD FLOORING ASSOC.
1 800 422 4556 OR www.woodfloor.org MY FLOOR CO WILL NOT FIX MY BUCKLED AREAS IN MY HOME AND HAVE BLAMED ME CLAIMING AND OUTSIDE FORCE HIT MY HOME . LIKE AN ALIEN . GOOD LUCK..IM IN FLA THE JUPITER AREA ..WHO KNOW ..MAYBE ITS THE SAME GUYS

Floating floor with excessive deflection has two main causes.
1. Edges tight to fixed verticle object. Floor buckls.
2. Sub-floor flatness not meeting specifications. Low spots in the slab surface with the flooring bridging the low spots. The floor moves excessively.

Common failure. Lack of floor preparation to bring the sub-floor into flatness requirements.

ray hit it dead on sorry but installer didnt know or care

Another place to find Certified Wood Inspectors:
www.NOFMA.org