Introduction: Time is Critical

A small roof leak can cause thousands of dollars in damage if left unaddressed. Water infiltration leads to rot, mold, insulation damage, and structural issues. This guide helps you detect leaks early and understand repair options.

DETECTING ROOF LEAKS

Interior Signs of Leaks

Obvious Signs:

• Water stains on ceiling: Brown/yellow discoloration
• Dripping water: Active leak during rain
• Bulging ceiling: Water pooling above drywall
• Peeling paint: Moisture behind paint

Subtle Signs:

• Musty odor: Mold growth from moisture
• Mold/mildew: Black spots on ceiling/walls
• Warped drywall: Slight bulging or sagging
• Stains in attic: Water marks on rafters/insulation

Exterior Signs of Leaks

What to Look For:

• Missing shingles: Gaps in roof coverage
• Curling shingles: Edges lifting up
• Cracked/damaged flashing: Around chimneys, vents, valleys
• Moss buildup: Holds moisture, lifts shingles
• Granule loss: Bare spots on shingles
• Sagging roof deck: Visible dips or sags

TRACING THE LEAK SOURCE

Why Leaks Are Hard to Find

Water Travels:

• Water enters at one point, travels along rafters/deck
• May drip 5-10 feet away from entry point
• Ceiling stain location ≠ roof leak location

Attic Investigation

During/After Rain:

• Go to attic during rain: See active leak
• Look for water trails: Follow water path upward
• Check insulation: Wet spots indicate leak above
• Inspect rafters: Water stains, rot, mold
• Mark the spot: Nail or spray paint to mark leak location

Safety Warning:

• Wet attic = slippery, dangerous
• Step only on rafters/joists (not insulation/drywall)
• Use flashlight, wear gloves
• If unsafe, call professional

Roof Inspection

Once Leak Located in Attic:

• Measure from fixed point (chimney, vent, wall)
• Transfer measurements to roof exterior
• Inspect that area for damage

Common Leak Sources:

• Valley flashing: Rust, separation, improper installation
• Step flashing: Missing pieces, gaps at walls
• Chimney flashing: Cracked sealant, separated counter-flashing
• Vent boots: Cracked rubber, separated from pipe
• Skylights: Failed sealant, cracked flashing
• Shingle damage: Missing, cracked, or lifted shingles

COMMON LEAK LOCATIONS

1. Valley Leaks (Most Common)

Why Valleys Leak:

• High water volume (two roof planes drain here)
• Flashing rusts over time
• Ice dams form in valleys
• Debris accumulates, holds water

Signs:

• Rust stains on valley flashing
• Separated flashing seams
• Water stains in attic along valley line

Repair:

• Temporary: Roof sealant ($50-100 DIY)
• Permanent: Replace valley flashing ($500-1,500 per valley)

2. Chimney Leaks

Why Chimneys Leak:

• Flashing sealant cracks/fails
• Counter-flashing separates from chimney
• Chimney crown cracks
• No cricket (water pools behind chimney)

Signs:

• Water stains around chimney in attic
• Visible gaps between flashing and chimney
• Cracked chimney crown

Repair:

• Temporary: Re-seal flashing ($100-200)
• Permanent: Replace chimney flashing ($800-2,000)
• Add cricket: If chimney wider than 30 inches ($1,500-3,000)

3. Vent Boot Leaks

Why Vent Boots Leak:

• Rubber boot cracks from UV exposure (10-15 year lifespan)
• Boot separates from pipe
• Nails through boot rust out

Signs:

• Cracked/split rubber boot
• Gap between boot and pipe
• Water stains in attic near vent pipe

Repair:

• DIY temporary: Roof sealant around boot ($20-50)
• Permanent: Replace vent boot ($150-300 per vent)

4. Skylight Leaks

Why Skylights Leak:

• Flashing sealant fails
• Condensation (not actual leak)
• Cracked skylight dome
• Improper installation

Diagnosis:

• Leak during rain: Flashing or dome issue
• Leak in cold weather: Likely condensation

Repair:

• Condensation: Improve ventilation, add insulation
• Flashing leak: Re-seal or replace flashing ($500-1,500)
• Cracked dome: Replace skylight ($800-2,500)

5. Ice Dam Leaks (Winter)

Why Ice Dams Cause Leaks:

• Snow melts from heat loss, refreezes at eaves
• Ice dam blocks drainage
• Water backs up under shingles
• Leaks into attic/walls

Signs:

• Icicles on eaves (indicates ice dam)
• Ice buildup at roof edge
• Leaks during/after snow melt

Immediate Fix:

• Remove snow from roof (roof rake)
• Create drainage channels through ice
• DO NOT: Use salt, heat cables on ice dam (damages shingles)

Permanent Solution:

• Improve attic insulation (R-40+)
• Improve ventilation (1:300 ratio)
• Extend ice & water shield to 72 inches (during re-roof)

EMERGENCY LEAK REPAIRS

Temporary Interior Fixes

Contain the Damage:

• Bucket: Catch dripping water
• Tarp: Cover furniture, belongings
• Poke hole in bulging ceiling: Allows water to drain (prevents collapse)
• Document: Photos for insurance claim

Temporary Exterior Fixes

Roof Tarp (Best Emergency Fix):

• Materials: Heavy-duty tarp, 2x4 boards, sandbags
• Installation:
  • Cover leak area, extend 4 feet beyond
  • Secure with 2x4s and sandbags (don't nail through tarp)
  • Extend over ridge if possible
• Cost: $50-150 DIY, $300-500 professional
• Duration: Good for weeks/months until permanent repair

Roof Sealant (Small Leaks):

• Use for: Small cracks, separated flashing
• Products: Henry's Roof Sealant, Geocel, Flex Seal
• Application: Clean area, apply generously, smooth
• Cost: $10-30 per tube
• Duration: 6-12 months (not permanent)

PERMANENT LEAK REPAIRS

When to DIY vs. Hire Professional

DIY Appropriate For:

• Single missing shingle replacement
• Re-sealing vent boot
• Small flashing repairs (accessible, safe)
• You're comfortable on roof, have safety equipment

Hire Professional For:

• Valley flashing replacement
• Chimney flashing
• Skylight repairs
• Multiple leaks (indicates larger problem)
• Steep roof (7:12 pitch or greater)
• Two-story or higher

Repair Costs (Fraser Valley, 2026)

Minor Repairs:

• Replace vent boot: $150-300
• Replace 5-10 shingles: $200-400
• Re-seal flashing: $100-300

Major Repairs:

• Replace valley flashing: $500-1,500 per valley
• Chimney flashing: $800-2,000
• Skylight flashing: $500-1,500
• Deck replacement (section): $1,000-3,000

PREVENTING FUTURE LEAKS

Regular Maintenance

Annual Inspection:

• Check for missing/damaged shingles
• Inspect flashing for rust, gaps
• Clean gutters (prevents ice dams)
• Remove moss (lifts shingles)
• Trim overhanging branches

After Major Storms:

• Check for wind damage (missing shingles)
• Look for hail damage (dents in vents, flashing)
• Inspect attic for new leaks

Proactive Upgrades

During Re-Roof:

• Extend ice & water shield: 72 inches at eaves (not 36)
• Full valley coverage: Ice shield entire valley length
• Upgrade flashing: Use thicker gauge metal
• Add cricket: Behind wide chimneys

INSURANCE CLAIMS FOR LEAK DAMAGE

What's Covered

Typically Covered:

• Sudden damage: Storm damage, falling tree
• Interior damage: From covered roof damage
• Emergency repairs: Tarping to prevent further damage

NOT Covered:

• Wear and tear: Old roof, lack of maintenance
• Gradual leaks: Slow leak over months/years
• Preventable damage: Ignored maintenance

Filing a Claim

Steps:

• Document damage: Photos of roof and interior
• Mitigate further damage: Tarp roof, move belongings
• Contact insurance: File claim within 24-48 hours
• Get estimates: From licensed contractors
• Adjuster visit: Insurance inspects damage

The Bottom Line

Roof leaks require immediate attention. Small leaks become big problems fast. If you can't safely access your roof or aren't confident in the repair, call a professional.

At RJ Roofing Bros, we offer emergency leak repair services. We'll tarp your roof to prevent further damage, diagnose the leak source, and provide a detailed repair estimate. We work with insurance companies and can help with claims. Call us 24/7 for emergency service.

Emergency leak? Call (604) 997-1292 - 24/7 service available