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To permanently close a crack and waterproof your foundation wall, Akton Injection in Montréal recommends exterior foundation crack repairs using an injection with multiple membranes depending on the requirements.

For best results, while requiring some excavation, an injection done on the exterior of your building can be combined with three membranes – liquid rubber membrane, rubber adhesive, as well as protection and drainage board. This combination provides the highest degree of protection possible.

The process of layering three membranes on the outside of the foundation wall ensures that the water will not get near the crack. Two elastomeric membranes to seal the foundation wall and the third a dimpled plastic drainage board called DELTA®-MS to eliminate any water pressure against the concrete, which is the primary reason for water infiltration.

Step 1: Lay plywood on the ground around the work area to keep the mess at a minimum.

Step 2: Excavate hole(s) approximately 3.5 feet x 3.5 feet to the footing.

Step 3: Scrape and clean the wall with wire brushes in preparation for the repair.

Step 4: Repair the crack with injection


Drill holes through the crack at a 45-degree angle every 6 inches.

Screw in injector plugs with grease nipples to connect with the high-pressure pumps.

Flush out the crack with a mild acid to remove dust, dirt, and debris from one injector to the next (removal of any obstructions for the injection).

Flush out the crack with water to clean out the acid. Water is also a reactor/accelerator for the polyurethane.

Cover the crack with hydraulic cement to prevent the outflow of the polyurethane from the injection.

Inject the polyurethane at 3000 to 10,000 PSI to fill all the open voids in the concrete and to push through to the other side.


Step 5: Remove the injectors and fill the holes with hydraulic cement for a smooth surface.

Step 6: Cover the hydraulic cement with 3 membranes


Aqua-Bloc 770-06 (liquid elastomeric membrane to seal the area)

Blueskin WP-200 (a rubber adhesive to seal the area)

Delta®-MS drainage board (rigid dimpled plastic to remove water pressure against the foundation and to protect the area during backfill)


Step 7: Install a drain board (Delta®-MS) to stop water pressure against the foundation. This protects the injection site and both membranes.

Step 8: Fill in the hole carefully without damaging the new membranes and making sure to keep any large stones away from the foundation.

Step 9: Clean the work area.


Learn more about the process with illustrations.



Is your basement finished? If not, interior repair is the most inexpensive option. If you want to repair a crack from the inside of your home and you have a finished basement, there will be additional contractor cost to repair the insulation, vapour barrier, gyprock, flooring, and paint increasing the expense to a point where you should consider an external repair. The most permanent solution is when you make a repair from the outside of the building. You get the same quality injection combined with multiple membranes providing the highest degree of protection possible.



Learn more when to use polyurethane or epoxy for your foundation wall crack injection.



If you have multiple cracks in your foundation or if you have a concrete block foundation, you may want to consider a full French drain for your home.



Since 1979, Akton Injection has specialized in the repair of concrete foundation walls and concrete block foundation cracks for over a quarter of a century. Just give us a call and our team of exterior crack repair specialists will work with you to find the best and the most cost-effective method to get a successful, permanent foundation repair solution.


Call one of our representatives today or fill out our form for a free foundation repair quotation!

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