Leveling above grade concrete floor for engineered wood flooring

[woodwrkrz]

My 1st and 2nd floors (over a basement) are conventional construction OSB subfloor with a 2" concrete slab poured over the top with embedded radiant floor heat. The system was designed with floor trusses engineered for the additional weight of the concrete and has been in place for 6 years. I am now planning to install my final floor coverings. My first project is about 600 sqft of Mannington engineered wood flooring (5" plank 9/16 thick designed for floating floor application). There are a few low spots which are 1/4" low or less, these could be fixed with some kind of leveler. The bigger problem is a high spot essentially a ridge above a bearing wall in the basement. The ridge falls in a straight line exactly between the living room and dining room and is as much as 1/2" high. I could create a detail between the two rooms using a different species of wood which runs parrallel to the ridge and eliminate the need for wood to span the ridge but I had planned to lay the wood perpendicular to the ridge which would emphasize the length of the combined room. What would be the least expensive and simpleist way to level my floor before installing the wood? I saw a segment of TOH or Hometime where they used dry sand to level the floor and then put the foam underlayment over the top of the sand before installing a floating wood floor, does anyone have experience with this technique? Any suggestions.

[Nichevo]

Gypcrete should be able to level that without much hassle.

[Paul Franklin]

If it's just that small section that's too high, I'd get someone to bring in a concrete grinder and grind it down. Assuming your radiant tubing is embedded deeper than the hump.

Make sure your flooring is rated for use over radiant heat; many aren't.

HTH,

Paul

[chickenwing]

that's a tough one. you will see the ridge especially after you combine the rooms

mmm mmm mmm

wait a min...how big is the area that is 1/2 too tall...

I tell ya, for the beauty of having the two rooms with continuous flooring..

why not consider a jack hammer and take out the high spot. done.

why didn't I think of that

[woodwrkrz]

Will any brand of gypcrete work fine. I recall we used a large bag of gypcrete to set my jacuzzi and my tubshower insert when we built the house. Is that the same stuff just mixed thinner? Also how big a mess does grinding the high spots off with a concrete grinder involve? Would I need to cover the already painted walls? Thanks for the input.

[Nichevo]

For the low spots gypcrete should be great, I have only seen it installed, they mixed it pretty thin, it was completely self-leveling.

I thought about grinding the high spot but I would be careful, it would be a shame if you hit or exposed one of the pex(?) tubes for the infloor heating. I would guess that grinding would be a little bit messy, but probably a lot cheaper if you can get away with it. The only thing that bugs me is that it may be even thinner than 2" at the high spot, it would be nice to know the actual depth. If the floor was already a little high for some reason high they may have only poured an

1-3/4" to cover the pex. If you take a half inch off that it will be getting pretty thin. I am sure there are guys on the group who have much more experience than I do with this flooring will have something to add.

Discalimer: I am no infloor heating, or floor leveling expert. But I will say that the guys who came in to gypcrete a building I did (that was laid in place pretensioned precast concrete(VERY ROUGH with huge bulges and dips)) made it look great, very smooth and level.

Oh, and definetly don't jackhammer anything like chickenwing said.

[Paul Franklin]

Concrete grinding does make a mess. It's done wet to keep the dust down, but you'd definately want to cover the walls right near where the grinding was going on to prevent spatter.

Paul