Putting new sub floor over concrete slab. how would i go about ataching it to the concrete .?

Question

glue or concrete nails and should i put down tar paper for moisture coming out of the concrete

Answer 1

I would use contact cement. Make sure you apply to both sides before putting them together. Use the contact cement liberally.

Answer 2

Use plastic ground sheeting instead of tar paper and use concrete nails, coat them with some sealer before you shoot them into the floor since the nail will make a hole that water can seep into if you don't.

Answer 3

It would depend on whether your slab has a moisture barrier underneath. For a room addition you would want a layer of gravel,a membrane and some sand (I think that's the order) in total it would be nearly a foot thick. If not,take care that the slab doesn't have a slope,i.e. exterior slab,paint on a layer of moisture resistant Epoxy, gun nail down 2X4 pressure treated "sleepers" on 16" centers and nail or s***w down some appropriate, subfloor plywood. Beyond that there are cloth membranes that can be applied under tile floors that allow the tile, to move to a degree, independent of the slab-to avoid cracks. You need to study this further to do a good job. No immediate answer here will suffice. Moisture should be a primary concern- concrete is only a 3-5" thick and is porous as well.

Answer 4

I would install what's called a floating floor......this will allow the concrete to expand and contract freely without your flooring doing the same thing.