Framing and Sub-Flooring - Framing subfloor over sloped concrete floor

Hello- not sure if this is the best section to post this question in, but I'll start here and move if this isn't. I have a 1600sq ft room with poured concrete floors over a wood floor. The building is an old carriage house, and the wooden floors are 2.5" thick with an inch or so of concrete on top(they drove cargo vans onto the floor in its last occupation, so its incredibly overbuilt with 12x6 beams in the basement). I'd like to put down another wooden floor on top of the concrete, but the floors are graded for drainage. I've had flooring firms come in and give estimates but they are astronomical (20k) and consist of pouring gypcrete over the existing floor. Framing was an option but I didn't get a price.

I'm planning on framing in over the concrete to get a level surface with 2"x3"s and then laying my ply over that, but I've never done something like this. Any pointers on how to best get a level line on a scale that large and a leveling the framing? Any tips appreciated, thanks in advance.


EDIT- just for understanding of the grade, it drops about 3 to 4 inches from highest to lowest point.

If its dropping 3 to 4", 2x3's aint gonna get it.

Have it overpoured, and talk to a concrete contractor, forget the flooring contractors.

Snoonyb - just so I understand, you are recommending that cutrhut level the floor with concrete, and then frame the floor?

I think he means level with concrete and then lay ply directly down on the then-level slab. I'll look into this option some more- I called a few concrete places but they didn't return my calls. The floors are painted over really oil soaked concrete, so the paint is coming up everywhere and I've degrease the clear spots to no end and the stuff keeps coming up. I have a feeling that might pose a problem for pouring concrete right over it, but I am out of my element there.

The topping may be not required to bond too well since it not going any place, It would just have to keep its continuity. In addition to gypcrete, you could also use lightweight concrete. It is stronger and a little heavier, but is frequently used in place of gypcrete. Most major ready mix concrete suppliers can produce lightweight concrete.

If uses the same aggregates as structural lightweight concrete, but is lighter and strong enogh for a topping. I have seen it used in a few homes.

Big River Industries, a part of Oldcastle, is a main supplier of the lightweight aggregate.

Dick

I think he means "forget the plywood" and have a cement contractor level the floor. What's the point of framing and plywood? Pour a level slab.

Snoonyb - just so I understand, you are recommending that cutrhut level the floor with concrete, and then frame the floor?

Absolutely not, "Concretemasonry" as well as "XSleeper" have come to the crux of the issue.

Any competent foundation or concrete contractor will tell the OP if additional use of an etching agent will be necessary to achieve adhesion, I suspect not.

Use this link as a resource to find any number of contractors in your area;
http://www.thebluebook.com/