Vapor Barriers and screed stakes

[LongGone12000]

I'm working on putting in a floor in a 40x72 shop. The ground can be a bit damp here in western Washington. As a result I was going to install a vapor barrier. After talking with the contractor he informed me that it wouuld do little good as he would be punching 40 or more holes in the vapor barrier for screed stakes.

The question is; how do you screed concrete without putting holes in the vapor barrier??

Thanks

Troy

 

[jike]

Screed stakes are not the only way to do it. How about setting wet screeds?

 

[jheidt2543]

Another way is to set the screed rail on little pads of concrete (cow pies).

Another point, yes screed stakes would punchure the vapor barrier, but the % of holes vs the total are is small. I would put the vapor barrier down, particularly if you intend to put any type of finishes on the concrete like tile, carpet, paint etc.

 

[udcguy]

Here in Wisconsin a vapor barrier / retarder is code. A few holes in it are no big deal. The contractor may not want the vapor barrier down because the concrete really should be poured stiffer and not have a lot of excess water that could bleed away to the grade below if there was no vapor barrier. Make sure the contractor doesn't steel trowel the surface untill all the excess water has reached the surface. Steel troweling it will seal the surface and not allow the excess water to bleed out and when the concrete then sets and the excess water dries out you'll get shrinkage cracks.
Use the vapor barrier, pour a good and not watery mix and finish the slab properly. ACI code has recommendations on how to do it right. This ain't rocket science but your contractor may be a little on the lazy side.