The foundation walls are the most important part of the building. They form the seat of the latter ensuring its structural stability.
The problems most often encountered by the structural engineer with respect to foundations are the following, namely:
- Foundation walls and / or floors that do not have the bearing capacity necessary to support the building;
- Insoles that are missing or too small;
- cracks in the foundation walls;
- Insoles which are not deep enough and which are therefore affected by the action of freezing and thawing cycles;
- Deterioration in concrete;
- Drainage - behind exterior walls - not adequate;
- The gelled embankment behind the foundation walls, etc.
Foundation Walls and Differential Settlements
The surficial map of the Montréal region clearly shows that there are clay-based seating surfaces whose bearing capacity is generally problematic. This low bearing capacity produced settlements and cracks in the foundation walls of buildings.
Generally, when there is a subsidence in the house, there are cracks and shears on the exterior siding as well as structural cracks in the interior walls. This shows a structural movement of the entire building.
The measurements of level readings external walls, using a laser level, demonstrate the presence or absence of a differential settlement in the latter. The engineer analyzes this data and assesses whether the measurements exceed the allowable travel criteria mentioned in Canadian Engineering Manual for Foundations.
If the differential settlement is considerable, it is necessary:
- Proceed to the stabilization of home soil.
- Repair cracks in foundation walls using tie plates to secure both sides of the foundation wall together.
- Seal these cracks from the outside to the sole.
- Properly repair shear in the brick siding to prevent water from entering the envelope and to ensure the integrity of this envelope.
- Check and replace any structural or other elements (beams, door columns, windows, seals, etc.) that are deformed or damaged due to subsidence of the building.
According to the mandate, our engineers can:
- Conduct an on-site expertise for the foundations;
- Analyze data and provide a verbal professional opinion;
- Write an expert report with photos, diagrams, findings and recommendations;
- Produce plans and specifications for corrective work.