Window sills and door Lintels Replacement.

Window Sills and Door Lintels Replacement – Structural Details That Matter

Window sills and door lintels are the unsung structural heroes of your home's façade. The sill sheds water away from the wall and protects the opening from moisture infiltration, while the lintel carries the weight of the masonry above every window and door. When these elements crack, corrode, or fail, the entire wall can shift, crack, or allow water damage deep into your home. At Longfield Masonry, we specialize in diagnosing and replacing failing window sills and door lintels across Montreal, restoring both safety and curb appeal.

Why Window Sills and Lintels Fail in Montreal

Montreal's freeze‑thaw cycles are relentless. Water seeps into hairline cracks in concrete sills, freezes overnight, and expands with enough force to spall the surface or push entire chunks away from the wall. Similarly, steel lintels hidden behind brick can rust and expand, causing the masonry above to crack or bow outward. Concrete lintels can crack under load or due to poor original reinforcement. Once the damage starts, it accelerates every winter unless properly repaired or replaced.

Masonry contractor in Montréal specializing in brick, stone, and chimney repairs, historic restoration, and custom masonry.

Inspecting for Hidden Damage

Most homeowners only notice the problem when they see visible cracks, water stains inside the house, or bricks starting to sag above a window. Our process begins with a detailed inspection of every opening. We check for movement, corrosion, spalling, and gaps in the joints. We also examine the surrounding masonry to ensure the damage is isolated to the sill or lintel and not a symptom of deeper foundation or wall issues. This diagnostic step ensures we fix the root cause, not just the cosmetic symptom.

Our Replacement Process

Replacing a lintel or sill is precision work that requires careful temporary support of the masonry above. We begin by installing structural bracing or needling to hold the wall in place while we remove the damaged element. For lintels, this often means carefully removing bricks or stones above the opening to access the hidden beam. Once exposed, we extract the old lintel and prepare the opening to receive a new galvanized steel or reinforced concrete lintel engineered to carry the actual load.

For window sills, we chip away the cracked or loose concrete down to solid substrate, clean and prep the surface, and either pour a new concrete sill in place or install a precast unit that matches the profile of your home. We pay special attention to slope, ensuring water runs away from the wall, and to the drip edge detail that prevents water from curling back under the sill. Every joint is sealed with high‑performance masonry sealant to keep moisture out.

Material Selection for Longevity

We use materials suited to Montreal's climate. Galvanized or stainless steel lintels resist rust far better than plain mild steel. Concrete lintels and sills are mixed with air‑entrainment and proper reinforcement to handle freeze‑thaw without cracking. Where aesthetics matter, we can cast custom concrete elements or source stone and precast units that blend seamlessly with heritage façades. Our goal is a repair that outlasts the original and requires no touch‑up for decades.

When to Call Longfield Masonry

If you notice cracks radiating from the corners of windows or doors, sagging bricks above openings, water stains on interior walls near windows, or crumbling sills, do not wait. These are signs of structural distress that will only worsen with each freeze. Whether you are renovating, selling, or simply maintaining your investment, Longfield Masonry delivers lintel and sill replacements that restore your home's integrity and value.

Get a Free Inspection and Quote

Protect your home from costly structural damage. Contact Longfield Masonry today for a free on‑site inspection and a transparent quote for window sill and door lintel replacement in Montreal.

Longfield masonry, 5220 Queen mary rd, (438)-861-9115