Among the foundation crack repair methods available, external crack repair is a good solution for leaking foundation cracks in poured concrete foundations. This waterproofing method is used when crack injection is not possible, or when a homeowner does not want to have a finished basement wall opened.

About Foundation Crack Repairs

Typically, we recommend, and our clients agree with, pressurized resin injection for most poured concrete foundation repairs because it is less expensive and typically less destructive than excavation; also, viewing the cracked concrete from inside the basement allows for an assessment of the cause of the cracking as well as the positive identification of the source of a basement leak. However, there are certain circumstances when it is best to repair a crack on the outside.

Such instances include:

1. Cracks behind the electrical panel, furnace, hot water heater, basement kitchen cabinets etc.,
2. When the homeowner has finished walls and does not want them disturbed; and
3. Other permanent fixtures preventing access to the face of the crack on the interior.


Exterior crack repair in progress
 An exterior crack repair in progress

Aquaguard Injection and Waterproofing® provides professional external crack repair services that are just as effective as crack injections.

The Steps to Repair a Foundation Crack From the Outside

How a crack is repaired from the outside is as follows:

1. We get the exact locations of underground gas and electrical lines (as well as other utilities) marked (this is required by law and generally requires at least 10 business days to obtain);
2. The crack location is then excavated to the footing, exposing the whole crack, from the top of the foundation to the bottom at the footing;
3. The wall is then cleaned and waterproofed using an elastomeric waterproofing membrane with integral flexibility and a strong chemical bond to the foundation wall surface. (The membrane is applied onto the wall all the way down to the footing in order to prevent the crack from leaking beneath the basement floor slab);
4. An air-gap membrane is affixed to the foundation wall over top of the waterproofing repair; and
5. The excavated area is backfilled and the site is cleaned up.

Important Considerations With Respect to Outside Crack Repairs

1. There must be sufficient clearance at the crack location in order to be able to dig; if not, the crack must be repaired from the inside. There must also be enough room to pile the soil in proximity to the excavation;
2. According to the Ontario Health and Safety Act, it is illegal for a person to be in an excavation deeper than 4 feet (unless shoring is used). Unexcavated soil caves in frequently and is unpredictable; therefore, safety is of paramount importance - and you should care about this because, if there is an injury while work is being done you will probably end up getting sued;
3. Once the excavated soil is backfilled there will be a mound of soil until this soil settles. The soil may settle quickly or may take up to a year or more depending upon the weather conditions in that specific location; and
4. Excavation in a residential setting is also weather dependent. Excavation should not be undertaken when it is raining and most mini excavators cannot break through frozen soil more than 2 inches in depth (if using a shovel, good luck with that).

External crack repairs to poured concrete foundations are a viable alternative to interior crack injection and are as effective as crack injections for basement waterproofing repairs. However, as excavation is involved, it is dependent upon the weather, quite destructive, and is three times more costly due to the amount of labour and/or the use of a mini excavator.

Click on this link for an article comparing foundation crack repair from the inside and the outside.

What separates us from our competitors is our attention to detail and safety. We always call for locates for buried electrical, gas and other lines. We have appropriate liability insurance, all employees have Workplace Safety and Insurance Board (WSIB) coverage, and we enforce safe excavation and work practices.

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