Onesta Building Council

In timber house, the wooden structure rests on the level (top) of the foundation walls. This structure located at the level of the foundation walls is composed of a smooth seat fixed directly against the foundation walls with anchor bolts. This is to ensure the lateral stability of the building structure.

Also, there is the Ledger board, joists of the floor, the intermediate covering of the support of the plancher as well as exterior walls.

To keep the structure wood in good condition [that which sits on the foundation walls], the ground level must not be higher than the junction between the top of the foundation walls and the base of the exterior cladding. The latter protects the wooden structure from above to the rail placed directly on the foundation walls.

Clearance

It is important to keep a space of at least 6 to 8 inches (clearance) between the base of the exterior cladding and the ground. This is to ensure that the wooden structure - which rests on the foundation walls - is higher than the ground level on the outside and that the foundation walls form a solid barrier of protection for this wooden structure (against water and moisture).

Structure rot

In houses where the wooden structure is lower than the exterior ground level, there is a high risk of this structure being rotted by humidity and water. There may be water infiltration, towards the inside of the building, by the leveling of the foundation walls, In addition, carpenter ants can be found in the wooden structure, as they proliferate in the damp structure.

During the pre-purchase inspection or an expertise for a building, the expert must check the level of the foundation walls in relation to the ground. In fact, he must measure the clearance between the ground and the base of the exterior cladding as well as the wooden structure resting on the foundation walls. The goal is to ensure that this clearance is adequate.

In the event that there is not adequate clearance or the ground is higher than the junction of the foundation walls, then it is necessary to check thestate full structure wood that rests on the foundation walls.

Rotten wooden structure, lower than ground level

Rotten wooden structure, lower than ground level