In Quebec, there are three types of foundations for buildings, namely poured concrete, concrete block and rubble (stone) foundations. In fact, foundation walls are the base of a building on which the frame and exterior walls rest.
Many types de loads can be applied to foundation walls, which must withstand loads. Among other things, these loads can be lateral pushes from soil and water as well as a force caused by freeze and thaw cycles.
There are also loads related to the weight of the building and snow loads. In the event that the loads are plus high that the capacity of the foundation walls and / or the bearing capacity of the soil (under the footings of the foundation walls), then cracks, subsidence, displacements and inclinations may appear, depending on the loads applied to the foundation walls and the type of foundation walls.
Block foundations of concrete and structural stability
It is recognized that concrete block foundations are of lower quality since they are sensitive to lateral thrusts du Sun. The reason is that these foundations are made up of concrete block units containing mortar (between these same blocks).
Concrete block walls are very weak and poorly withstand lateral forces, as they easily lose their structural integrity. In addition, the blocks can move and move independently. Therefore, concrete block walls should not be installed when there are significant lateral forces, coming from a high ground level, or significant hydrostatic pressure in front of the foundation walls.
The high lateral forces cause damage with concrete block walls. So walls can tilt and crack and blocks can shift to such an extent that the walls lose their structural integrity and become lead free.
If we choose to install concrete block walls, we must armor these walls and fill the rows of cells, with concrete, so that these walls can withstand the lateral loads applied to them.
Block foundations and water infiltration
In general, concrete block walls are not not waterproof because of the mortar joints connecting the concrete blocks together. Water can penetrate the concrete blocks and fill the drains, and then seep inwards. This is because concrete blocks are relatively porous. The water infiltration andhigh humidity, in concrete block walls, cause mold to form as well as rotting of the structure (which rests or touches the foundation walls).
It is very important when buying a building to be aware of the type of foundation and if it is concrete block foundation then two aspects should be carefully considered, namely structural stability of these walls and the waterproofing thereof.
Over the years, we have handled several latent defect cases relating to concrete block foundation walls.