Here is the problem that was submitted to us by a candidate for the purchase of a duplex in Montreal before making his final decision to invest in this building. 

I want to buy a house in Villeray in Montreal, but while visiting it, the owner seller mentions (with a certain pride) that he dug his own crawl space so that he can stand up there and easily keep the watch for possible leaks from pipes because in the past a smoke test had revealed the weaknesses of the old pipes.

If at first, I released a Woahh of admiration about the colossal work that this represents, I then worried about the possible weakening of the foundations… and given the general state of the place through foundation repair Utah.

  • Is it legal?
  • What are the risks?
  • What to check to be sure that the integrity of the house is not in question by such an initiative.


The owner we are talking about is prohibited because he should have

  • Check city/district regulations, as they are often different
  • Present the documents required for an application for a permit to dig the crawl space.

For excavation work in the crawl space, municipalities generally require the following documents and documents:

  • A certificate of location.
  • An engineering plan for the structure.
  • An architect’s or technologist’s plan for the interior fittings, in the case of a living space development project.
  • A contract with a contractor.

The expertise of a foundation specialist

First of all, be aware that this type of work requires good expertise and that only the companies registered with the RBQ who carry them out are covered with guarantees and insurance that protect both their company and their customers.

In the present situation, we do not forget that the foundations support, not only the load-bearing perimeter of the house but also the transverse beams and other H beams which in turn support the floors and the load-bearing divisions of the house.

Digging lower than the base of the foundation is quite risky because the foundation will no longer have the same stability and will undergo an external thrust which will weaken the structure over time. Call on VOPAA Inc. foundation repair contractor.

Lowering the level of a crawl space

Lowering the level of a crawl space represents a job of great complexity since it directly affects the structure of the building. A failure in the realization can have big consequences. It is essential to consult a structural engineer for the development of a plan. He can guarantee that the renovations will be done safely and that the result will respect construction standards.

The contractor has to follow the instructions of the engineering plan in the letter. The method for lowering the level of the crawl space, therefore, varies from case to case, but it is generally required to support the entire building.

The nature of the terrain and the materials of the foundation can lead to difficulties

The structure of the unique foundation also joins the stakes of such a project.

The foundations will be deep and their materials, chosen according to whether the ground is clayey, sandy, rocky, etc.

But in Montreal, digging a crawl space is particularly risky, because the soils are often clayey. The dug cavity dries out the clay under the existing foundations and promotes their subsidence with the help of Utah foundation repair.

Moreover, by partially digging the crawl space, the excavated soil must not touch the joists, because the slightest humidity in the soil will quickly be transmitted to the old wood and will cause these precious supports to rot.

General Council:

Check the ventilation of the crawl space during the summer because it is necessary to minimize the ambient hygrometry of the crawl space against the risk of rot.

We also note that the foundation materials are also representative of the period in which it was built.