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View Full Version : What is meaning of positive drainage for foundations?


Steve Drain
Sep 13, 2008, 09:23 PM
I would like to determine what the definition is for positive drainage for foundations in residential home construction. I have seen it defined on websites where this type of drainage system drains to either daylight or to a sump pump crock.

The term drainage as defined in Webster's is the act, process or mode of draining. The problem I have in my house is my basement and perimeter drains are in the water table. Since the perimeter drains are in the water table, water is not being drained from around the perimeter. The pipes are sitting in the water. The pump can run continuously for 6 months in my area until the water table goes down as I am on bedrock. I am on the Niagara Escarpment.

Are there any engineers out there that can give me some insight or provide a book or article that explains what positive drainage is and is not.

Thank you
:confused:

smearcase
Sep 14, 2008, 05:08 PM
Positive drainage has always meant to me that the drainage is going in a direction downhill and away from the structure you are trying to protect from water damage.
This is one definition:
Glossary of Foundation Terms - Integrated Foundation Solutions (http://integratedfoundationsolutions.com/info/glossary.htm)
If feasible, it sounds like you need to put in some large 12" or larger drains down at the elevation of the perimeter drains and have good fall in the drain to a point well away from the building. Or maybe some grading around the house but without seeing the property and depth of drains, that may not be feasible.