Foundation Crack Repair

On closer inspection, we can identify different types of crack, each giving an initial idea of the state of the property.

Passive Cracks

Firstly, there are passive cracks. Passive cracks are those that do not widen over time. In general, these cracks are simply a sign of the normal aging of the house and only affect the surface. Simple sealing is usually enough to repair them.

Active Cracks

On the other hand, an active crack poses greater risks. If the crack continues to worsen over time, you should consult an expert as soon as possible. They will be able to determine the origin of the concern and carry out the necessary repairs. Active cracks are often caused by ground subsidence, poor drainage or frost.

Cracks can be caused by many factors, each with its own dynamics. Some of the main causes of cracking are: 

Natural Aging of the House 

Over time, it is inevitable that cracks will appear in a property. These cracks, although common, are mainly the result of structural movement and the natural degradation of materials.

Frost

When winter sets in and the water around the house freezes and solidifies, the ground can lift and shift, exerting pressure on the walls of the house. This can lead to the appearance of cracks or the aggravation of existing cracks, depending on the intensity of the frost. 

That's why it's advisable to minimize nearby sources of water, such as gutters, to reduce this risk.

Step 1: Preparing the Site 

Before any work is carried out, a mini-excavator is used to dig around the foundation, exposing the damaged area. This step is crucial to ensure full access to the crack without compromising the existing structure.

Step 2: Cleaning and Opening the Crack 

Once the crack is accessible, we clean it by removing any debris, dirt or damaged material. The crack is then opened in a 'V' shape to allow better adhesion of the repair material. This method increases the contact surface of the repair material and ensures a more solid integration.

Step 3: Installing the Injection Ports 

Injection ports are installed along the crack at regular intervals, typically every 8 inches. These ports will act as channels for injecting the polyurethane under high pressure.

Step 4: Applying Rapid-Setting Cement 

A rapid-setting cement is applied to the inside of the prepared crack. This type of cement is chosen for its rapid hardening and robustness, guaranteeing effective and lasting closure of the crack.

Step 5: Injecting Polyurethane

Polyurethane is injected under high pressure through the injection ports. This expanding material effectively fills the crack from the inside out, creating an impermeable barrier that prevents any future infiltration. 

Injection is carried out gradually to ensure even distribution of the polyurethane and to avoid any excess pressure that could further damage the foundation.

Step 6: Installing the Waterproofing Membrane 

A waterproofing membrane is applied to the entire repaired area. This membrane is specifically selected for its flexibility and ability to follow ground movements, which is essential to prevent further cracking.

Step 7: Installation of DELTA® MS Membrane

After installation of the first waterproofing membrane, DELTA® MS is applied as an additional layer of protection. This special membrane is designed to guide the flow of water to the French drain, preventing water infiltration through the walls. 

Its unique structure allows adequate ventilation and prevents moisture build-up, which is essential to protect the foundation against water and moisture damage.

Step 8: Backfilling and Compacting 

The soil is carefully backfilled, using excavated material or other suitable materials, to ensure adequate consolidation. The soil is compacted in layers to prevent any future subsidence that could compromise the repair.

Step 9: Quality Control and Finishing 

Once the repair is complete, a quality control check is carried out to ensure the integrity of the repair and that it is watertight. The area is then levelled and cleaned for a neat finish, leaving little trace of the work.