Drywall Water Damage Repair After a Roof Leak - Toronto Home Case Study

Had a significant roof leak last January (ice dam - now fixed) that caused substantial drywall damage in two upstairs bedrooms. Posting the full repair process and cost.

The Damage

Ceiling in master bedroom: approximately 12 sq ft of saturated and sagging drywall. One interior wall also affected along the exterior wall intersection. Visible water staining, some mold growth in the corner where the ice dam was worst.

Step 1: Find and Fix the Source First

Before any drywall work, the ice dam and roofing issue causing the leak was addressed. New attic air sealing and insulation upgrade eliminated the ice dam source. Only after that was confirmed fixed did we proceed with drywall repair.

Step 2: Mold Assessment

A small area with visible mold growth prompted us to do a basic air quality test ($280). Results showed elevated mold spores in the room. Mold remediation was done before drywall repair: remove affected drywall, treat framing with antimicrobial, allow to dry fully (used dehumidifier for 1 week).

Step 3: Drywall Repair Scope

  • Ceiling: remove 6x6 ft area (cut to joists), replace with new 1/2" drywall
  • Wall: remove 4x6 ft section, replace
  • Total new drywall installed: ~52 sq ft

Finishing

Taping and mudding was done in 3 coats over 4 days. Ceiling was the hardest part - matching the orange peel texture required 2 practice attempts on scrap board before getting it right with a hopper gun.

Total Cost

Mold remediation + air quality testing: $1,450
Drywall materials: $280
Labour (demo + install + finishing): $1,800
Painting (2 rooms primed + 2 coats): $1,100
Total: $4,630

The root cause fix (ice dam / attic work) was separate: $3,100. Do not pay for repairs without fixing the cause.