Your concrete,
our expertise

Complete waterproofing:
residential, commercial or institutional.

  • Specialists in construction and surface maintenance
  • Robust and durable waterproofing solutions
  • Certified local expertise and guaranteed work
Emergency service: (438) 700-8556

Get your free quote today!

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Integral solutions to protect your structures

Our expertise, your advantage.

Peace of mind, durability and elegance: that's what we guarantee.

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Watertightness of horizontal slabs

High performance membranes for terraces, balconies and concrete floors.

Each of our manufacturers and installers has a minimum of 10 years of experience in the field. We rigorously select our team for their expertise and attention to detail.

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Foundation wall protection

Multilayer systems that block humidity and hydrostatic pressure.

All of our manufacturers and installers work exclusively for Geo Stone, we do not subcontract, which ensures total quality control at every stage.

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Sustainable roof terraces

Bilayer or liquid solutions resistant to UV and freeze/thaw cycles.

Each installation is covered by a 5-year warranty, ensuring peace of mind and lasting confidence in the quality of our work.

Waterproof junctions

Precise sealing of slab-wall transitions, parapets and technical penetrations.

Each of our manufacturers and installers has a minimum of 10 years of experience in the field. We rigorously select our team for their expertise and attention to detail.

Repairs and upgrades

Injections, joint repair and over-sealing to extend the life of structures.

All of our manufacturers and installers work exclusively for Geo Stone, we do not subcontract, which ensures total quality control at every stage.

Each installation is covered by a 5-year warranty, ensuring peace of mind and lasting confidence in the quality of our work.

Inspection and preventive maintenance

Annual visual audits and adherence tests to detect defects before they cost a lot.

Long-lasting protection against
infiltration, freezing and wear.

At Geo Stone, we don't just sell counters, we offer surfaces that are durable, refined, and designed to transform your daily life.

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Integral waterproofing

Zero infiltration

We apply a high performance continuous membrane, capable of blocking the water, humidity and corrosive agents (such as de-icing salt) at the surface as well as at depth.

Even the most exposed capillary microcracks and joints are treated.

The result: a slab protected over its entire surface, with no weak spots or possible infiltration.

Extreme resistance

The materials we use are rigorously selected for their exceptional resistance. to freeze/thaw cycles, abrasion, hydrostatic pressure and heavy loads typical of exposed concrete structures, such as slabs, foundations and technical surfaces.

Our sealing systems preserve the structure of your slab despite the harshest weather conditions.

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Quebec winter

Simplified maintenance
Easy access

Our intervention process is designed to limit interruptions in use: no prolonged closure, no invasive construction site.

We intervene quickly, in a clean and controlled manner, allowing in many cases the resumption of activity the same day. Perfect for condominiums, commercial or institutional buildings.

Local know-how

Each project is carried out by a team trained, certified and supervised by more than 30 years of expertise in building envelope via Toitures LV.

We understand the challenges that are unique to Quebec constructions and we know exactly how to adapt our solutions to your soil, climate and structural realities.

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Dedicated team

Why choose Tréfond Montreal?

At Erco, the word Service isn't just a selling point: it's our reason for being. Each interaction, each project, each detail reflects our commitment to listen, to deliver a turnkey service and to exceed your expectations.

FAST

Extend the life of your floor slab up to 20 years

A level of excellence that reflects our attentive listening and our commitment at each stage.

FAST

Design, installation and follow-up under a single roof

Un niveau d’excellence qui reflète notre écoute attentive et notre engagement à chaque étape.

FAST

30 years of recognized local expertise

Un niveau d’excellence qui reflète notre écoute attentive et notre engagement à chaque étape.

15,000

Quality electrical installations delivered with care, for homes and businesses throughout Quebec.

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Before
After

What if your slab lasted 20 years longer?

Take action now. Ask for a free quote.

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FAQ (Frequently asked questions)

Why trust us?

Why does a deep slab have to be absolutely watertight?

Located below ground level, the deep slab is continuously exposed to humidity and hydrostatic pressure; without a membrane, water migrates to the concrete, feeds the corrosion of the reinforcements and causes cracks or bursts (spalling).

What warranty is offered?

Written guarantee of 10 years on the integrity of the membrane, extensible to 20 years with our biennial inspection program (photo report + spot adhesion test).
The warranty covers labour and materials.

What is the actual lifespan of the treatment?

With minimal maintenance (annual visual inspection and drain cleaning), the membrane offers up to 20 years protection before the first partial reconditioning. Longevity depends on three factors: quality of the support, exposure to chemical agents (chlorides) and frequency of surface cleaning.

How do I know if my slab really needs treatment?

Alarm signals: white efflorescence, persistent dark spots, concrete chips (spalling), visible corrosion of reinforcing bars, infiltration into the lower ceiling. A drop absorption test or humidity reading can confirm excessive porosity.

How is the construction site going and how long should it take?

  • Diagnosis and coring as needed (½ day)
  • Surface treatment: high-pressure cleaning, mechanical stripping, crack repair (1 to 2 days)
  • Application of membrane and sealants (1 day)
  • Accelerated cure time (6 to 12 hours) the parking is partially operational during preparation; full access is restored as soon as the cure time is over.

Is the treatment compatible with an old coating?

Yes, as long as the old coating still adheres securely.
Otherwise, mechanical stripping is planned. our membranes adhere to concrete, epoxy, polyurethane and asphalt-concrete after adequate preparation.

Can I have an existing structure waterproofed without stopping it for a long time?

Yes: a polyurea system allows partial return to service the next day. for parking lots, we proceed by zones in order to maintain up to 75% of the places accessible during the work.

What maintenance after waterproofing?

  • Quarterly gentle wash to remove salts and hydrocarbons
  • Annual visual inspection of joints and drains
  • Redo the peripheral sealant every 5 to 7 years
  • This program maintains watertightness and extends the warranty up to 20 years.

Do you serve my region?

We serve all of Greater Montreal and the surrounding areas.

How long does it take to get started?

Generally under 7 to 10 working days after the submission has been accepted.