Expert: Dan Griffin - 9/15/2008

Question
QUESTION: Brick home slab floor and water seeping in after rains and wetting carpet.Is there a membrane/product to seal water out to put between wall and soil. I know slanting lawn away from building more is need. This room has a step-down about 6 inches. thanks

ANSWER: Bill, almost can't happen unless you have flower beds or other dirt higher than finish floor.  Highest dirt on the outside should be 6" below finish floor and then fall away at least another 6" in the first 10 feet by code.  This would be an extremely difficult thing to waterproof after the fact.  Buildings can be designed to deal with it, but it would not be normal and would cost a great deal more even when dthey are being built.  Get the dirt graded properly, it is always a pet peave of mine to see minimal, marginal, or indadequate drainage.

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QUESTION: This is only in one room with 6 inch step-down and (yes) dirt is higher than finished floor. The outside wall is 12'. I thought I might do both..waterproof and grade dirt...

Answer
You can excavate to the joint between the footing and the exterior finish material.  I assume it is brick.  I want to guess the water is not coming in through or under the footing unless you have  a very high water table and ponding water on the outside.  I am guessing that the problem is where the brick meets the footing.  Clean the surfaces well and treat with emulsified tar, I would use at least two coats or more to a point above grade.  There is a sheet product called EPDM - about the thickness, color, and consistency of an innertube.  I would apply this material to cover, protect, and waterproof the wall face.  There is a thin section aluminum bar called a termination strip to hold the top of the EPDM.  I would use Powers brand Nailin anchors to hold the termination bar through the top of the EPDM sheets into the brick or mortar joint.

Again the primary treatment would be to correct the exterior grade.