I'm installing a bath in my basement. When I broke the cement foundation, I found that the entire basement was covered with a layer of plastic. Under the plastic was about 4" to 5" of pea gravel. Under the pea gravel is a lot of damp clay. I plan on putting the pea gravel and new plastic back after I lay the drains. Why did the contractor use plastic? Is this code? Is it done frequently?
06:36PM | 09/07/03
The plastic is a vapor barrier used to keep moisture from entering your basement through the floor. The pea gravel is a drainage area to keep water away from the underside of the slab. This is the proper way to pour a concrete slab. When you patch the floor back you should replace the stone and take the time to patch and seal around the edges of the vapor barrier.
GlennG: What do you mean "patch and seal around the vapor barrier". I was going to replace the pea gravel and plastic then pour cement over the barrier and then feather it out smoothly to match the exsiting pour. Is'nt that the correct way? Should I include another step? The project is so small, I think that I can do this properly...Your advice is much appreciated. The trench is 17'x 27" Thank You. P.S. I layed the pea gravel yesterday. I used the plastic bags that the pea gravel came in as a vapor barrier. I bought 50 bags @ 50lbs each from Home Depot. 2,500lbs total. This cement work ain't no joke!! Back/knees are hurting!!! I truly admire you cement/brick layers!!!
[This message has been edited by torint (edited September 08, 2003).]
02:18PM | 09/08/03
By sealing around the edges I was referring to the plastic vapor barrier. If possible it should be taped or sealed using other means where it was cut or punctured. Any holes left in the plastic barrier are potential points of entry for moisture.