Messages and Online Forum Q&A

Re: leaky underground garage and tunnel

From: info@builderswebsource.com
Category: Foundations and Basements
Remote Name: 63.198.181.43
Date: 27 Apr 2001
Time: 06:42 PM

Comments

It sounds like your problem is due to two possible problems:

1) Cracks in the concrete garage ceiling, walls or slab which are allowing water to penetrate;

2) Insufficient, or lack of foundation drainage to relieve hydrostatic pressure in the first place.

Anytime you build an underground structure, such as a basement or garage, it must be properly engineered to include a perimeter drainage system and sump.

A perforated french drain (with holes facing down) must be provided along the entire circumference of the structure, and backfilled with drainage rock. The french drain must lead to a sump which is below the slab grade, where ground water can be pumped out before it rises too high.

Furthermore, the walls and ceiling of the garage must be properly waterproofed on the outside, using a bitumen topcoat or stick-on membrane. Bituthene is one example.

Without seeing your condition first hand, we can only speculate about the proper remedy. We recommend that you contact a civil engineering company that specializes in drainage. They may be able to offer other suggestions or remedies specific to your conditions.

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