Window sills in older Montreal homes are much more significant than they might appear at first glance. These horizontal structural components play a critical role in preventing water infiltration, safeguarding the walls, and ensuring the surrounding brickwork stays aligned and durable.

In traditional brick facades, sills are essential for protecting masonry from water damage, as they act as a barrier that channels rainwater away from the wall surface. By preventing moisture from penetrating brick joints, they help preserve the structural integrity and aesthetic charm of these historic buildings, while also minimizing erosion and wear over time.

It’s remarkable how these understated architectural elements uphold the character and longevity of Montreal’s iconic homes!

At JV Deco, we specialize in removing and replacing window sills with precision masonry techniques and durable materials. With years of hands-on experience across Westmount, NDG, Verdun, and the Montreal area, our team has worked on all types of properties—from duplexes to heritage homes.

As spring arrives and freeze-thaw damage becomes visible, it’s the ideal time to check your sills for signs of wear and consider a professional replacement.

What Exactly Is a Window Sill?

In masonry, the window sill is the solid base that sits just below the window. It’s often made of concrete, limestone, or stone, and it performs several essential functions:

• Water Redirection: Window sills are designed to slope outward, allowing rainwater to run off away from the wall and foundation. This prevents water from pooling, which could lead to leaks or structural weakening over time.
• Preventing Wall Saturation: By directing water away, sills help avoid water soaking into the walls, which could cause mold, mildew, or even deterioration of materials like brick, stucco, or wood.
• Sealing Gaps: Properly installed sills create a tight seal where the window meets the wall, reducing the risk of water seeping through gaps during storms or heavy rainfall.

If your sill is cracked, sagging, or flaking, it may no longer be doing its job—and the longer you wait, the worse it can get.

Common Signs Your Sill Needs to Be Replaced

• Visible Cracks or Chips
  Freeze-thaw cycles in Montreal’s winter can cause cement and stone to crack over time.
  
• Water Infiltration Around the Frame
  Stains or mold near the bottom of the window are often caused by water penetrating through a damaged sill.
  
• Loose Mortar Joints Beneath the Sill
  This can be a sign that the sill is shifting or not distributing weight properly.
  
• Discoloration or Erosion
  A weathered surface may indicate that the sill’s waterproofing has failed.
  
• Soft or Crumbling Edges
  Especially common in old concrete sills that have started to degrade from repeated water exposure.
  

Why Spring Is the Ideal Time for Sill Replacement

Montreal winters are tough on masonry—and spring is when that damage becomes most apparent. Here’s why many of our clients choose this season to replace their sills:

• Milder temperatures allow materials to cure properly
  
• Melting snow reveals hidden cracks or shifting
  
• Prepares your home for the rainy season, reducing risk of water infiltration
  
• Optimal time to coordinate with other exterior masonry work, such as repointing or lintel repair
  

Our Process: Sill Removal and Replacement

At JV Deco, we take pride in a thorough and efficient process that ensures long-lasting results:

1. Inspection and Assessment

We evaluate the condition of your existing sill, surrounding brickwork, and structural supports. If there’s water damage, we check for hidden signs of deterioration inside the wall.

2. Safe Removal of the Old Sill

Using diamond-blade masonry saws and hand tools, we carefully remove the damaged sill without disturbing the surrounding structure.

3. Material Selection Based on Your Property

We offer several durable options:

• Limestone from local quarries (ideal for heritage buildings)
  
• Precast concrete (cost-effective and clean finish)
  
• Custom-cut natural stone (for premium results and longevity)
  

4. Precise Installation

The new sill is bedded in fresh mortar and aligned to maintain slope and drainage. We also ensure that weep systems are unobstructed to allow proper water flow.

5. Sealing and Finishing

We apply professional-grade sealants at all junction points to ensure full waterproofing. Finishes are matched to the original aesthetic.

6. Final Inspection and Clean-Up

We complete a detailed check to ensure the sill is structurally sound, weather-tight, and visually consistent with the facade.

Case Study: Limestone Sill Replacement in Westmount

A homeowner in Westmount contacted us after noticing water stains beneath several of their second-floor windows. The original concrete sills were over 70 years old and had begun to crack and shift, allowing rainwater to seep into the walls.

What We Did:

• Removed and disposed of six deteriorated sills
  
• Installed new limestone sills sourced from Saint-Marc
  
• Resealed all perimeter joints
  
• Repointed mortar under the window openings
  

Result:

The homeowner saw an immediate improvement in water protection and the overall look of their facade—without the need for costly interior repairs.

Why Choose JV Deco for Sill Replacement in Montreal?

With years of experience in masonry work, JV Deco is a trusted choice for sill replacement throughout the Greater Montreal Area. Our approach combines:

✅ Technical Expertise – We understand the structural role sills play and install them with precision.
✅ Quality Materials – Limestone, concrete, and natural stone options.
✅ Tailored Solutions – We adapt our process to the architectural style and condition of your home.
✅ Clean, Efficient Worksites – We respect your property and always leave the job site clean.
✅ Licensed & Insured – Fully RBQ licensed and compliant with all local building standards.

Ready to Replace Your Sills? Start with a Professional Assessment

If you’re seeing signs of deterioration or water damage, don’t wait until the problem spreads. Contact JV Deco today to schedule a no-obligation consultation. We’ll assess your sills and provide expert advice on the best course of action.

Call us at (514) 889-7947

Or fill out our online contact form to request your quote

JV Deco – Your trusted partner in masonry and window sill replacement across Montreal.