Regina, Saskatchewan is built on 30 feet of lakebed left over from the last ice age. This lakebed material forms the soil of a region stretching from Moose Jaw and east to Winnipeg. Often referred to as gumbo soil, clay, or any number of other names, the soil absorbs water easily and shifts a lot throughout the year. As the soil shifts and moisture levels fluctuate, the soil puts hydrostatic pressure on basement walls and foundations, eventually leading to failure. This soil can expand by as much as 25-35% by volume, pushing in basement walls and heaving basement floors.
There is very little preventative maintenance that can be done – properly grading your yard and maintaining adequate drainage can help extend the life of a foundation, but it is likely that every home in the area will eventually need to have foundation repairs done. Those repairs can take on many forms. Here are some of the most common types of repairs:
Basement Wall Bracing
As the soil exerts pressure on the basement wall, the wall can push in at the top, bottom, or middle. This can be identified by houses shifting off the foundation wall, bowing basement walls, or cracks appearing in exposed concrete. When a home needs wall bracing, an engineer is brought in to inspect the extent of the damage and draw plans to correct the problem or prevent further damage. The repair involves the installation of several steel beams installed vertically against the wall, anchored to the floor joists by large anchor bolts and to the concrete floor by mortar. The beam is then mortared in place and any cracks are sealed with a polyurethane caulking. The final product is inspected by an engineer and the city to ensure that the completed work complies with the permit.
Pony Walls/Knee Walls
Basements in older homes were often built with concrete blocks or even stones; because of the number of joints in the construction, this type of basement can not be braced in the same way as a poured concrete basement. Instead, a Pony Wall or Knee wall is installed. This wall is a poured concrete wall on the inside of the existing basement wall that braces the old wall and helps to support the home.
Moisture control is extremely important when it comes to basement repairs. Some homeowners may be lucky enough to catch problems small while they are easily corrected, others will have problems so severe that additional moisture control measures must be taken to prevent even more problems down the road. In each instance, the solution is often an exterior dig-out. A dig-out involves removing the soil from around the perimeter of a house (or side of a house) down to the foundation. The wall is then repaired, sealed, and covered in a water proof membrane. Then, weeping tile is installed, with the drains from the front of the house exiting toward the street, and the drain on the rear of the house exiting toward the backyard. Finally, the excavation is filled with sand to improve the drainage of water and reduce the influence of hydrostatic pressure on the walls. Top soil and proper grading and landscaping complete the job.
Teleposts are a common fixture in most basements. These steel posts are attached to foundation pads under the basement floor and to beams, joists, or flooring above. Over time, the foundation of a home can shift, leading to uneven floors and cracking drywall. Our experts can adjust the teleposts in your home to ensure that everything is level and solid, preventing costly repairs down the road.
Sometimes, the basement wall has shifted so far that it becomes unsafe and it must be straightened as well as braced. In this case, the a combination of items must be performed to bring the structure back into shape. First a dig-out must be performed to give the wall the flexibility to be moved and to allow the wall to be repaired and waterproofed. Then, braces are installed inside the wall to prevent further damage. Next, pressure is applied to the walls via the structural steel braces to accurately reposition the wall into the correct spot.