concrete topping

[johnnyf]

Hi all, I am new to this board seems like alot of great information here. My question is I have an existing pole barn with concrete floor no vapor barrier but sealed and it sweats like crazy when the weather changes. I would like to heat the building with in floor radiant heat. would it be better to bust out the old and start over or can one pour on top of the old. any advise would be be great. floor size is 32 x 40

John

 

[larry4406]

Not sure how to address your lack of vapor barrier, but I have capped garage slabs with a new pour when the original was poured at the wrong elevation.

The concrete contractor roughed up the surface, blow the debris off, applied a bonding agent, and then poured the new slab on top of the existing slab along with 6x6 welded wire mesh.

This was all new construction when the first slab was set low by mistake. The first slab had a 6 mil poly vapor barrier under it.

 

[WolverineCoatings]

I have an idea but I have a question first.

How deep do you have to put the radiant heat tubes in the concrete?

 

[johnnyf]

I would think the tubes would only need to be just under the surface ? an inch or so under the slab

John

 

[D KRAGER]

I've seen it done in house. Lay the tubing down and then cover it with thinset, just enough to cover the tubes, but then covering with ceramic tile. I guess it would work with concrete. I'm not sure about the vapor barrier, I don't know if you could go ahead and put one down. With the floor heated it may not sweat anyways. The floor only sweats when it is colder than the outside air. The slab warms slower than the air, but if the slab is heated there won't be any condensation.

I have a vapor barrier under my slab in a pole building, and it will still sweat when the slab is cold and the outside temp warms up very quickly. So the vapor barrier won't fully solve the problem anyways.