Saw cutting · Excavation · Pouring · Garages · Basements · Commercial
Concrete slab replacement in Montreal
When a slab has sunk, cracked clean through or is crumbling across a large area, repairing it no longer holds. It has to be replaced. We handle the whole job: saw cutting the existing slab, demolition and removal, excavation, preparing the base and pouring a new slab — then, if you want one, an epoxy floor or polished concrete on top. Here is how it works, step by step.
- RBQ licence 8005-0081-14
- 5-year warranty
- CNESST compliant
- Residential, commercial, industrial
When does a slab need replacing?
Most cracked slabs can be repaired. Replacement becomes necessary when the problem is in the slab itself, not just on its surface:
- The slab has sunk, heaved or tilts to one side
- It is cracked clean through, or pieces have broken loose
- The concrete is crumbling or flaking across a large part of the surface
- Cracks keep opening despite repairs
- Work under the slab means opening it up over a large area
The steps of a slab replacement
Every job is different, but the order of the steps is not. Everything is set out in the quote before we start.
1. Assessment at the estimate
Nicholas comes to look at the slab himself. He checks its condition, measures, looks at access for equipment and for hauling debris out, and confirms that replacement is really needed. If a repair will do, he tells you. You then receive a detailed written quote.
2. Saw cutting the existing slab
The slab is saw-cut into sections. Saw cutting gives clean edges and lets us remove only the part being replaced, without damaging walls, foundations or the part of the slab that stays.
3. Demolition and removal
The cut sections are broken up, lifted out and hauled away. The area is left ready for excavation.
4. Excavation
The ground under the old slab is excavated to the depth set out in the quote. This is often where we find out why the slab moved in the first place.
5. Preparing the base
The base that will carry the new slab is prepared and compacted. A slab is only as good as what is under it: this is the step that decides whether the new slab stays put.
6. Pouring the new slab
The concrete is poured, spread and finished. The thickness, reinforcement and other specifications of the slab are specified in the quote, based on how the space will be used.
7. Curing
Concrete keeps gaining strength for weeks after it is poured. When you can walk on it, store things on it or drive on it depends on the job: the schedule is set in the quote, and we keep to it before moving on to the next step.
8. Floor finish (optional)
Once the slab is ready, it can take an epoxy floor — flake, solid colour, metallic or marble — or be polished. Preparation is the same as on an existing slab: diamond grinding, then the EF-160 MVB moisture-barrier primer for epoxy.
What the quote spells out
A slab is designed around what it will carry: a car, a workshop, warehouse racking or machinery. Rather than quote general figures, we write them down for your project:
- The area to be replaced and where the cuts go
- The excavation depth and how the base is prepared
- The thickness and reinforcement of the new slab
- The schedule, including curing time before use or before a finish
- The floor finish, if there is one
Who it’s for
Residential: sunken or broken garage and basement slabs, often redone ahead of an epoxy floor.
Commercial and industrial: slab sections in stores, warehouses and plants, with mobilization planned with you to limit downtime.
Interior slabs are done year-round. For outdoor work, the Quebec season is short — about 16 weeks — so it pays to plan early.
How it works
Call and estimate
We come out, measure, and hand you a detailed quote.
Mechanical preparation
Diamond grinding of the concrete with CNESST-compliant dust extraction.
Repairs
Cracks and imperfections filled with epoxy or polyurea.
Vapour-barrier primer
A membrane against moisture in the concrete.
Base coat and finish
Flake, metallic or solid — your choice.
Polyaspartic topcoat
A protective layer resistant to UV and abrasion.
Cove bases and drains
4-inch cove base and custom stainless-steel drain covers.
Frequently asked questions
Does a cracked slab always need replacing?
No. Most cracks can be repaired with epoxy or polyurea. We recommend replacement only when the slab has sunk, is broken or is crumbling over a large area. We tell you at the estimate, before any work starts.
When can I use the new slab?
It depends on the slab, how it will be used and the conditions on site. Concrete keeps gaining strength for weeks; the exact schedule — before you walk on it, drive on it or apply a finish — is written into the quote.
Can epoxy go on a new slab?
Yes, once the slab is ready. It is then diamond-ground and receives the EF-160 MVB moisture-barrier primer, just like an existing slab. When the finish can go on is part of the schedule in the quote.
How much does a slab replacement cost?
The price depends on the area, access to the site, what we find under the old slab and the finish you choose, if any. We come out for free and give you a detailed written quote, with no obligation.
How does the estimate work?
Call us at 514-659-9802 or fill in the form at the bottom of the page. We come out, measure, look at the condition of the concrete and give you a detailed written quote. The estimate is free and there is no obligation.
See also
Service areas
- MontrealPlexes, downtown storefronts and condo parking garages.
- LavalAttached garages and basements, Saint-François to Sainte-Dorothée.
- LongueuilFrom Old Longueuil to Saint-Hubert, through the tunnel.
- BrossardDIX30 and Solar condos, garages in the residential sectors.
- TerrebonneNewer homes from Lachenaie to La Plaine, up the 25.
- AnjouHome base on Avenue de Louresse, and three garages in our gallery.
- BouchervilleSuburban garages and an industrial park, just out of the tunnel.
- Saint-LaurentWarehouses, workshops and plants on the west island, via the 40.