Water infiltration through the roof : what to do?

A roof leak can quickly become a serious issue, leading to structural damage, mold growth, and interior deterioration. Whether caused by severe weather, natural wear, or lack of maintenance, a roof leak requires immediate action to prevent costly repairs and maintain the building’s integrity.

This guide explains how to detect a roof leak, identify its causes, and implement effective solutions to minimize damage.

How to Detect Water Infiltration Through the Roof?

A roof leak can go unnoticed until visible damage appears. Identifying early warning signs helps prevent costly repairs and protect the building’s structure.

Indoor Signs of Water Infiltration

The first indications of a roof leak often appear inside the building:

• Yellowish or brownish water stains on ceilings and walls
• Dripping water or moisture accumulation, especially after heavy rain
• Blistering or peeling paint and plaster, indicating water saturation

If you notice these signs, take immediate action to prevent mold growth and structural deterioration.

Exterior Signs of Roof Damage

A visual roof inspection can reveal potential infiltration points:

• Missing or damaged shingles, allowing water to seep under the roof
• Cracked or loose flashing and sealants, especially around chimneys, skylights, and vents
• Standing water on a flat roof, a sign of drainage failure

These visible damages suggest advanced wear or poor installation that must be addressed before leaks worsen.

What Causes Water Infiltration on a Roof?

Water leaks on flat or sloped roofs can result from various factors, ranging from natural material deterioration to extreme weather conditions. Identifying the root cause ensures a long-term solution and prevents recurrence.

Roofing Material Deterioration

The roof covering plays a crucial role in waterproofing, but exposure to the elements causes gradual deterioration.

• Broken or cracked tiles create entry points for water.
• Displaced or missing shingles expose the underlayment to moisture.
• Aging or punctured flat roof membranes significantly increase leak risks.

Poor Water Drainage

Improper drainage can cause water stagnation, leading to roof infiltration.

• Clogged gutters (due to leaves, ice, or debris) prevent proper water evacuation.
• Blocked drains on a flat roof cause moisture buildup.
• Insufficient slope slows water runoff, weakening roof waterproofing over time.

Faulty Flashing and Seals

Junctions between the roof and structural elements (chimneys, skylights, vents) are prone to leaks.

• Loose or cracked flashing and worn-out sealants allow moisture to seep in.
• Poorly sealed fastenings gradually compromise roof waterproofing.

Severe Weather Conditions

Extreme weather events are a major cause of roof leaks:

• Strong winds and storms dislodge shingles and weaken roof structure.
• Freeze-thaw cycles create cracks as materials expand and contract.
• Heavy snow and ice accumulation put pressure on the roof, increasing the risk of ice dam formation.

What to Do Immediately in Case of a Roof Leak?

When a roof leak occurs, quick action is crucial to minimize damage and avoid expensive repairs. Follow these steps to protect your home before a professional roofer arrives.

Secure the Area to Minimize Damage

• Move water-sensitive objects (electronics, furniture, documents) to prevent damage.
• Use buckets or plastic sheets to contain leaks and prevent floor and wall damage.
• Inspect ceilings and walls for signs of structural weakening.

Pro Tip: If the leak is severe, avoid touching damp areas near electrical outlets or wiring. Turn off electricity if necessary.

Locate and Contain the Leak

• Observe visible water stains and trace moisture paths.
• Inspect the attic or crawl space to identify the leak’s source.
• Check the roof exterior for damaged shingles, cracked flashing, or compromised membranes.

Note: Water may travel a significant distance before appearing inside, making leak detection complex.

Temporary Measures to Limit Water Damage

• Cover the affected area with a protective tarp, inside or outside, to reduce further infiltration.
• Remove standing water from the roof without damaging the surface.
• Clear gutters and drainage to ensure proper water evacuation.

Expert Tip: Avoid using sharp tools to remove water or ice, as they may damage the roof further.

How to Repair a Roof Leak?

Fixing a roof leak promptly prevents structural deterioration and reduces repair costs. Depending on the damage’s severity, two repair types are possible:

Temporary Fixes to Contain the Damage

Before a professional roofer arrives, temporary repairs help protect the roof:

• Seal minor cracks with waterproof caulking or emergency patches.
• Cover damaged areas with a secured tarp to block further infiltration.

These temporary solutions are not permanent but can limit immediate damage.

Permanent Repairs Based on Roofing Type

Shingle Roof Repairs

Replace damaged or missing shingles to restore the roof’s protective barrier, and apply sealant around flashing and vents to enhance waterproofing and prevent water infiltration.

Flat Roof Repairs

Inspect and repair damaged waterproof membranes using thermal sealing or adhesive patches, while reinforcing drainage points and sealing around walls and water outlets to ensure effective water evacuation and prevent future leaks.

Tile or Slate Roof Repairs

Repositioning displaced tiles helps prevent water infiltration, while replacing cracked or broken tiles immediately ensures the roof remains waterproof and protected from further damage.

How to Prevent Roof Leaks?

Preventative maintenance reduces repair costs and protects the building’s structure. Regular inspections and proactive measures improve roof waterproofing and increase its lifespan.

Routine Maintenance: Inspections and Cleaning

• Annual inspections help detect early signs of wear (cracks, missing shingles, weakened seals).
• Gutter and drain cleaning ensures proper stormwater runoff.

Tip: Schedule roof inspections after winter and fall, as debris and snow accumulation can cause damage.

Seal and Flashing Checks Before Winter

• Inspect flashing around chimneys, skylights, and vents for cracks.
• Reapply sealants where needed to maintain a watertight barrier.

Small cracks can quickly worsen during freeze-thaw cycles.

Additional Protective Measures

• Install snow guards to prevent ice dam formation.
• Use a secondary underlayment as an extra moisture barrier.
• Apply a waterproofing membrane to increase resistance to harsh weather.

For flat roofs, reflective coatings reduce UV damage and temperature stress.

Why Hire a Professional for Roof Leak Repairs?

A roofing expert ensures durable, effective repairs. A certified roofer provides a detailed diagnosis, identifies the exact cause of the leak, and implements long-term solutions to prevent recurrence.

At Les Couvreurs Duro-Toit, we offer professional, guaranteed repair services for leaks and roof maintenance. Our team enhances roof longevity by reinforcing waterproofing and weather resistance.

Don’t let a leak compromise your roof – contact our experts today for fast, effective, and lasting solutions!