The purpose of foundation wall inspection is to define the type and current condition of these foundations, and to recommend an appropriate solution to repair, stabilize or improve these foundations.
The problems most often encountered by the Onesta structural engineer in relation to the foundations are the following, namely:
1- Soles that are missing or too small;
2- Structural cracks in the foundation walls ;
3- Footings that are not deep enough and are therefore affected by the action of freezing and thawing cycles;
4- Deterioration in the concrete;
5- The drainage – behind the exterior walls – not adequate;
6- The frost-susceptible backfill behind the foundation, etc.
Foundation Walls and Differential Settlements
The map of unconsolidated deposits in the Montreal region clearly shows that there are clay- based bearing surfaces with generally problematic load-bearing capacity. This low load-bearing capacity has led to settlement and cracking in the foundation walls of buildings.
Generally, when there is subsidence in a house, cracks and shearing are found on the exterior cladding as well as structural cracks in the interior walls. This indicates structural movement of the entire building.
Level measurements of the exterior walls, taken using a laser level, demonstrate the presence or absence of differential settlement. The foundation expert (structural engineer ) analyzes this data and determines whether the measurements exceed the allowable displacement criteria specified in the Canadian Manual of Foundation Engineering.
If the differential settlement is considerable, it is necessary:
1- Proceed with stabilizing the foundation of the house.
2- Repair cracks in the foundation walls using the tie plates to secure the two sides of the foundation wall together.
3- Seal these cracks from the outside up to the sole.
4- Properly repair the shears in the brick facing in order to prevent water infiltration into the envelope and to ensure the integrity of this envelope.
5- Check and replace all structural or other elements (beams, columns, doors, windows, sealing joints, etc.) that are deformed or damaged due to building subsidence.
Depending on the mandate, our foundation expert can:
1- Carry out an on-site inspection of the foundations;
2- Analyze data and provide a professional opinion for the condition of foundation walls;
3- Write an expert report with photos, diagrams, findings and recommendations;
© The ground subsided, causing a major crack in the foundation wall.
© Laser device for taking level readings for foundation walls