Pouring Concrete

[Evie]

Half our basement is dirt and we would like to finish it with a concrete floor. Eventually we will make an extra room there. We have heard different stories about how we need to do this. We have an 8 inch depth. We have been told to put down plastic on the dirt, then 4 inches of gravel and then 4 inches of concrete. Then someone else told us do not put plastic down, just do the 4 inches of gravel then concrete.

Does anyone have any experience in this?
Thanks so much.

[jimbrown]

You did not say where you are.

Here in Arizona they don't use the plastic. It is too dry.

If you live somewhere where its damp you better put down plastic. The thick kind not the cheapo thin stuff. Thats my opnion.

[Pat]

Are there radon concerns in your area? If yes, then yo will need to put perforated drain pipe in the gravel and vent it safely outside.

A good barrier to put down is StegoWrap.

If you put gravel under the slab you may need to have a drain to handle water ingress. If you intend to place tile on the floor you will need very porous tile or an under slab drain system.

Pat

[Evie]

We are in NC. We took your (J Brown) advice and did a radon test for 3 days in the basement and got a 3.1 reading. According to the stats a 4.0 is the acceptable limit. We are stilling thinking of doing the drain. Also we have some holes and cracks that need patching. Could you explain in layman's terms how to actually do a drain of this type.

Thanks for your help.

[pinkie]

My hubby is a mason and I've never heard of plastic. He uses rebar and gravel. Then he pours the concrete in. You can hire it done, the concrete truck will come and dump it in and you just have to finish it. Are you doing it yourself?

[Handyman]

I would use a crush and run type gravel (it has a lot of powered in it), compact it and then lay a layer of heavy plastic to control moisture from coming thru the concrete. The gravel under the plastic will allow for moisture under the concrete to go where ever. Not to mention the plastic will act a termite barrier.