Crack repair

Causes and solutions for crack repair


What causes cracks?

Cracks are sometimes linked to completely natural phenomena. Concrete is not elastic and undergoes shrinkage that creates small cracks that are often harmless. However, you should never ignore a crack. It is essential that you keep an eye on it and make sufficient repairs so that it does not become a source of water infiltration. These repairs are even more essential if your foundation walls are not protected by an effective waterproofing process.

The other most frequent causes of cracks:
  • Movements and swelling of the soil, especially when it is clay-based
  • Uplift of foundations due to freezing
  • Tree roots that are located too close to the foundations
  • Poorly constructed foundations
  • Poor balancing of the weight distribution of the house during construction
  • Problems associated with pyrite in the backfill or concrete foundation walls and floors
  • A French drain in disuse or an iron ochre problem
  • A physical shock on the house or excavation work carried out in an unsafe manner
  • Work on the house that jeopardizes the stability of its structure
When we don’t see them, what are the signs of possible cracking?

Apart from visible cracks, there are many symptoms that indicate that your home does not have effective protection against external waterflow. Do not neglect the warning signs. They should be taken seriously and addressed immediately because they could inflict serious damage on your home.

When we don’t see them, what are the signs of possible cracking?

The most common signs are:

  • An excessive degree of ambient humidity in the basement
  • Signs of moisture on the walls
  • Excessive condensation on windows and roofing
  • Water accumulation on the floors
  • Musty, mouldy, or bad odours and fumes
  • Softened plaster
  • Crumbling concrete or the formation of salt deposits on concrete surfaces
  • The formation of black spots and mould on walls, fabrics, or woodwork
  • Rotting floors

If you notice that some of these symptoms appear in your basement, you are definitely dealing with the problem of cracking or you don’t have adequate waterproofing of your foundation walls.

Before taking action

Cracks in your foundation can occur for many reasons and repairing them can be a complex undertaking. You should seek the advice of a specialist before undertaking any repair work. Don’t hesitate to ask for our expertise as a Réno-Maître, general contractor, specializing in crack repairs and waterproofing of foundations. We can identify the causes and find appropriate solutions.

You can choose between two solutions:


  • Injecting cracks through the interior with polyurethane foam. This is the least expensive method and the injection is guaranteed for a period of 5 years.
  • Spraying cracks through the exterior, including excavation. We exclusively perform crack repairs by applying RUB-R-WALL. This revolutionary product provides the following advantages:
    • It dries quickly and doesn’t deteriorate over time
    • It’s ecological and doesn’t give off toxic products
    • It can be installed in any season starting at 4°C
    • It has an incomparable elasticity, even at low temperatures down to     -26°C
    • It repairs and stems cracks up to 3.2 mm (1/8 in) wide


Any repair carried out this way is guaranteed for 25 years.


Injecting concrete is a method to fill a void that occurs with closed formwork. Using a pump, we inject a non-shrink concrete formulation that doesn’t decrease in volume during the curing period.


If your house has basement windows which open directly to the exterior ground level or lower, they must always be equipped with window wells, also called “skylights” or “light wells,” as well as adequate drainage. Without this type of device, rainwater can accumulate on the rim and in the window and then infiltrate, damaging everything in its path. Your windows and your foundation walls may undergo serious damage. Frequent moisture can also generate decay and cause spreading of bacteria and fungi that are harmful to your health.

The Durasec Solution
  • Adjust the levelling and ground level of windows to create clearance
  • Conduct a crushing process and add a drainage system, resting on your French drain (not connected) around the perimeter of the window
  • Install a metal window well or masonry that will isolate the ground from the drainage area and prevent excessive water runoff from your lawn to your windows

By carrying out this type of improvement, moisture and water will not stagnate anymore along your windows and they will keep up a nice appearance for a long time. Your basement will be protected from all moisture and infiltration from this source.


Whether you want to build a new downward-sloping basement entrance or replace an existing one that’s feeling the effects of time and freezing, or even build an areaway, Groupe Durasec’s techniques are a durable solution.

A downward-sloping basement entrance made with formwork insulated for concrete will allow you not only to do a high-quality job, but will also give you a wide range of finishing possibilities that you can do yourself thanks to finishes of recycled plastic available in a variety of colours.


Who’s never been confronted with the scary sight of a garage filled with water due to a catch basin that’s too small at the bottom of their downward-sloping garage entrance?

Don’t worry, we have the solution! Whether you have a double or single garage, we will adapt your gutter accordingly. At the same time, you’ll be protected, even during a downpour.


It’s possible that during the initial excavation, the depth wasn’t respected, additional material was added to the bottom of the excavation and it didn’t have the bearing capacity to support the weight of the footing and the foundation wall. With a void underneath, the footing can then crack, creating a space between the wall and the footing.

It’s also possible that the footing was poured onto frozen ground, causing a similar result. In this situation, the footing sags and cracks when thawing.

In both cases, it’s critical to rectify the situation since the sagging footing will lead to cracking of the foundation walls and the siding if it’s rigid, for example of the brick or the stone.