Written by Bob McGuire on December 16th, 2008

Hydraulic Cement

There’s been a lot of information on the web lately saying that the best way to patch a leaking crack in poured concrete basement walls is to chip out the crack and smear on hydraulic cement, and force it into the crack.  Bad advice.

Concrete walls crack because as concrete ages and dries, it shrinks.  As concrete shrinks in a wall, a weak spot will crack.  Common places for cracks to appear is next to a window, a beam pocket or even a string of rod holes.

The key word in hydraulic cement is CEMENT.  It will shrink the same as cement in concrete shrinks as it ages.  While hydraulic cement may work for a year or two, eventually it will shrink and make a new crack, or seam, to let water in again.  Hydraulic cement is an inexpensive and easy fix, but is not a good idea if you intend to do any remodeling or improving your basement.  Inexpensive hydraulic cement can be an expensive repair if you have to tear out cabinets or ceramic or a shower.

At Oakbridge Construction, Waterproofing Division we use Hydrofobic Foam to repair cracks.  Hydrofobic means that the foam reacts to the presence of moisture. We actually squirt water into the crack just before injection to activate the foam. This foam expands into every space, forming a seamless barrier to stop water. This hydrofobic foam does not shrink or crack as time passes.

If someone tries to repair a crack with hydraulic cement, and it leaks again, we have a fragmented and filled crack that we can’t inject with foam.  Foam needs to be injected into a fairly clear path, so we have to do a lot of extra work to clear the cement out of the crack.  Extra work means extra cost for you.  So save money by calling a pro first.

Much of our work is with previously repaired cracks. This photo shows what I have been talking about. This crack was patched with a layer of hydraulic cement. Then a layer of white material that looked like vinyl, followed by another coat of hydraulic cement.  With all that effort, the crack still leaked. This crack and a couple leaking rod holes put 1/2 inch of water on the floor.

Forget hydraulic cement.  We can get rid of water for good.  Call us NOW.  248-834-0050.

Basement Waterproofing 2