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Chicago Exterior Crack Repair – Sodium Bentonite Stops Seepage

Jan 21, 2013 • By Matthew Stock with Ben Shachter.

Chicago Exterior Crack Repair – Sodium Bentonite Stops Seepage


As long as homes have had basements, homeowners have been dealing with seepage.  As soon as a builder digs a hole in the ground and builds a foundation in it, ground water goes to work, trying to find its way in.  One of the most common ways occurs when surrounding soil, expanding due to saturation, causes foundation walls to crack.

And, as long as there have been basement wall cracks, there’s been somebody out there ready to fix them.  Like many other forms of home repair, foundation crack repair has had its share of new ideas, but one early method is still in use today because it works.

How Does a Chicago Basement Waterproofing Contractor Use Sodium Bentonite to Stop Seepage from Foundation Wall Cracks?

One method of repairing basement wall cracks is the use of sodium bentonite, a granular clay, to form an impermeable dam against the wall from the exterior.  Sodium bentonite is one of a family of bentonite clays; it’s a chemically inert, organic material that is dug from the earth and supplied in powder form.  Besides basement waterproofing, it is also used to cap old water wells and for sealing dams and landfills.

To repair a foundation wall crack using sodium bentonite, the basement waterproofing contractor first locates the site of the crack on the exterior of the home.  Then, he digs a small hole against the foundation, down to the bottom of the footing.  The hole is then filled nearly to the top with the clay powder and is covered with soil so there is no outward sign of the repair.

In average soil conditions, the dry sodium bentonite absorbs water from the surrounding earth, which causes it to expand and harden, sealing the crack.  In dry conditions, the installer may add water to get the process started.  In any event, the repair created by the sodium bentonite clay process is permanent and durable.

There are, of course, other methods for repairing foundation wall cracks, most notably urethane injection performed from the interior of the basement.  In this process the basement waterproofing company seals the crack with epoxy after inserting a number of injection ports.  Expanding polyurethane is then injected into the ports, filling and sealing the crack to the outside soil.  This newer technology is more commonly used today but is not always applicable in all situations.

When is Sodium Bentonite the Best Choice for Foundation Crack Repair?

Because sodium bentonite is applied from the exterior of the foundation, it is an obvious choice when the crack is not accessible from the inside of the basement.  This is usually because the basement has been finished and the foundation walls have been covered by drywall or paneling that the homeowners does not want to remove.  In other instances, the interior of the basement may not be accessible for crack repair because of how it is being used or due to other construction.

There are a few obstacles to the use of sodium bentonite that limit access to the site of the crack.  For example, if a patio, sidewalk or driveway covers the ground next to the foundation the basement waterproofing contractor can use the sodium bentonite process in that spot but will have to chip out the paving material and patch it afterward.  Trees or significant landscaping close to the foundation also present a problem and may have to be removed.  It is possible, though, to partially dismantle wooden structures such as decks or porches to gain access.

Even though the sodium bentonite process is a relatively simple one, Chicago homeowners are best served by a basement waterproofing contractor that is intimately familiar with the process and its alternatives.  When U.S. Waterproofing started out in business more than 55 years ago, its only service was exterior crack repair and the company has constantly refined its Wall Clay™ process at the same time it has branched out into other areas of basement waterproofing and foundation repair.  Why not ask their experts for their free advice?

Tags: cracks in basement walls, exterior foundation crack repair, chicago basement waterproofing, basement waterproofing chicago, sodium bentonite

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