Horizontal moisture Barrior for P-T foundation

[inaz]

Project is residential tracked home development.

To help reduce center/edge lift and edge moisture penetration, I wanted to recommend a horizontal barrier extending away from the slab.

I envision a strong UV resistant geomembrane like one of the Permalon products placed 4 to 6 inches below the surface and wrapped down into the footing trench.

I'd like some product recommendations and installing and securing the product.

Also, anybody know of a way to find the Thornthwaite moisture index for an area. I've tried Dept. of Agriculture, but no help. The post-tension institute manual is quite poor on this point.

Thanks allot for any comments.

 

[Focht3]

Get the Thornthwaite moisture index for the National Weather Service.

Moisture barriers don't work for houses - too many penetrations during construction: water, sewer, gas, phone, cable, sometimes electric. (My neighborhood has buried electrical lines. No power poles - very nice.) And let's not forget trees, decks, pools, etc. that are installed after the home is built.

Increase the slab's stiffness - that's the only answer that works reliably.



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora. See faq158-922 for recommendations regarding the question, "How Do You Evaluate Fill Settlement Beneath Structures?"