How Foundation Cracks Develop

Cracks can be found in almost all residential foundations. Often, they will occur in corners of windows, pour lines, holes for service lines or rod ties. The various causes include:

1. High water content resulting in poor concrete mix
2. Rapid curing of concrete
3. Concrete forms removed prematurely (i.e. 2 days instead of 7 days)
4. Fill soil being improperly compacted
5. Uneven moisture around the foundation
6. Poor drainage
7. Hydrostatic water pressure

All houses will settle, but because soil properties vary, not every point on a foundation will settle uniformly, thus causing cracking walls and racking door frames. Good construction will minimize overall settlement and prevent differential settlement.

In time, even small cracks will grow larger and can cause BIG problems like loss of structural integrity. All cracks that may be or are exposed to moisture need to be repaired as quickly as possible to avoid extensive damage.

Type of Basement Wall Cracks

Hairline Cracks

Most foundation cracks will appear within the first year of being built. Common wall cracks do not pose any structural concerns, or failure of foundation. The biggest problem with these, is water leakage.

Vertical Cracks

1. Typical foundation cracks run vertically or at an angle, this is caused by the shrinking of the concrete as it cures, this is true with settlement.
2. Horizontal cracks at mid point of the wall are subject to lateral pressure causing the wall to bow and damage the wall structurally

Cracks more than 1/4” wide, horizontal cracks, cracks with misaligned edges or continued movement may require an engineer assessment. Monitor the cracks length and movement by making the ends of the crack and making alignment marks at various points on the wall.

Horizontal Foundation Crack

Vertical or Hairline Foundation Crack

Service Vehicle

Crack Injection

Crack injection works by filling the full width and length of the crack with a liquid epoxy or an expanding polyurethane foam. This is a permanent repair and does not have to be repeated. unlike other surface repairs the injected polymers are not exposed to weathering, traffic, or ultraviolet rays.

Most importantly, injection of the cracks will prevent expensive repairs and problems in the future. Potential damage done by water leaks to the finished basement or cost of repairing concrete walls caused by corrosion show the clear advantages of permanent crack repair.

Injection is the best repair of poured concrete walls.