# Concrete floors



## stuart45 (Jun 20, 2009)

I would put over the top, over a bed of sand binding as well to protect it.


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## Canucker (May 5, 2011)

http://www.buildingscience.com/docu...floor-problems?topic=resources/flooring-probs

Skip the layer of sand , no need for it.


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## stuart45 (Jun 20, 2009)

Depends where you are. Building regs here insist on sand binding over hardcore to stop any punctures of the slab.


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## Canucker (May 5, 2011)

True, building regs. do tend to lag behind in some areas of code


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## stuart45 (Jun 20, 2009)

Looking on that link they were talking about sand on top of the vapour barrier, which doesn't make sense. However without sand underneath the DPM there have been problems with damp coming through where the hardcore has punctured the plastic. Depends on how damp your climate is.


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## Canucker (May 5, 2011)

If I'm interpreting it correctly, the crushed rock is a drainage layer, followed by vapour barrier, then the concrete. The only problem that a hole gives it, is that you would have vapour diffusion the size of the hole through the concrete. Standing water under the slab would wick through it though, which is a completely different issue.


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## stadry (Jun 20, 2009)

ohfercrhssakes, quit arguing back & forth :laughing: just use 15mil vb & be done w/it,,, we use no sand under OR over our vb nor have we ever,,, then again, we never place conc over only a crushed stone base :no:


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## cleveman (Dec 17, 2011)

Yeah, I put a vapor barrier right on top of the rock and pour the concrete on that.


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## jomama45 (Nov 13, 2008)

stuart45 said:


> Depends where you are. Building regs here insist on sand binding over hardcore to stop any punctures of the slab.


You're not supposed to be pouring concrete in your golf cleats Stu......:laughing:

Here, we pour directly over the VB, being cautious not to puncture it. Plywood strips to wheel on & concencious workers goes a long ways.


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## stuart45 (Jun 20, 2009)

jomama45 said:


> You're not supposed to be pouring concrete in your golf cleats Stu......:laughing:
> .


Thanks Joe, I know where I've been going wrong now:laughing:


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