How to remove a load-bearing wall in a Montreal plex.
Removing a load-bearing wall in a Montreal plex requires plans sealed by an engineer who is a member of the Ordre des ingénieurs du Québec and a permit issued by your borough. The wall is replaced by a beam resting on columns, and the load then has to be brought back down to a support able to carry it, often down to the foundations. Count on six to twelve weeks between the first steps and the end of the work.
How to know whether my wall is load-bearing
Three clues give a good indication even before having someone come over.
The direction of the joists. A wall perpendicular to the direction of the floor joists is a serious candidate. A parallel wall is much less so.
Vertical alignment. If a wall sits in the same place on every floor, including the basement where it often becomes a beam or a row of columns, it's almost certainly part of the load path.
Thickness and solidity. A load-bearing wall is generally thicker and sounds solid.
These clues point, they don't conclude. In a Montreal plex modified once or twice since construction, the real load path frequently departs from the apparent logic. Only an on-site survey can settle it.
Why an engineer is mandatory
In Quebec, analyzing and sizing a structure are acts reserved to engineers by the Engineers Act. No contractor, however experienced, has the right to perform them.
It isn't an administrative formality. It's what makes the chosen solution verifiable, what ensures your insurer will cover the building, and what keeps a future buyer from discovering in ten years that a structural change was made without a document.
The contractor's role is to coordinate the engineer's mandate, carry the permit application and execute the sealed plans to the letter. That's our role at ASA.
What the borough requires
A transformation permit is required. The file generally includes the plans sealed by the engineer, a description of the work, and depending on the case an architect's plan.
Requirements and lead times vary from one borough to another. The same project doesn't move at the same pace everywhere on the island. It's the schedule item that overruns most often, simply because nobody is actively following it.
In a condominium, the association's authorization is also needed, and common areas can't be modified without its consent.
Underpinning, the step that quotes forget
It's the most important point of this article.
A load-bearing wall spreads the load along its whole length. A beam concentrates it on two points: its supports. Those supports now transmit a significant point load to whatever is underneath.
If the floor, the beam or the footing below haven't been reinforced to receive it, the load lands on a structure that was never planned for it. Nothing happens on the day the work ends. The problem shows one to three years later: floors sagging in the middle, doors that stick, cracks that come back after every repair.
In a plex, that reinforcement often runs through the units on the lower floors, sometimes down to the foundations. It's work, coordination with occupants, and cost.
When you compare two quotes and the gap is large, that's where to look first.
How long it takes
Survey and engineer's mandate, one to three weeks. Permit application and issuance, two to six weeks depending on the borough. Work, one to four weeks depending on the extent of the underpinning and the finishing.
Six to twelve weeks in total is a realistic order of magnitude for a simple project. A project touching several units or a condominium takes longer.
What makes the price vary
The length of the opening and the type of beam required, steel or engineered wood. The depth of the underpinning, which is the main factor. The presence of plumbing, electricity or ventilation in the wall to remove. Access to the site. Occupancy of the units during the work. The extent of the finishing afterwards.
So, what are we working on?
Eight questions, two minutes. We call you back to talk it through, and we tell you frankly whether it's a project for us or whether you'd be better served elsewhere.