How do I fix a shower that's leaking into the floor below after a renovation?

A shower leaking into the floor below after renovation typically indicates a waterproofing failure in the shower pan, tile work, or plumbing connections — this needs immediate attention to prevent structural damage and mold growth.

The most common culprits after renovation work include improper waterproof membrane installation, gaps in tile grout or caulking, or disturbed plumbing connections. In New Brunswick's older homes (especially those 1970s-1990s split-levels common in Riverview and suburban Moncton), post-renovation leaks often occur because the original shower wasn't properly waterproofed to modern standards during the update.

Immediate steps to take: Turn off water to the shower immediately and place buckets below the leak in the room below. Remove any wet drywall or insulation in the ceiling below to prevent mold — New Brunswick's humid climate makes mold growth rapid, especially during our wet spring months. Document everything with photos for potential warranty or insurance claims.

Diagnosing the source requires systematic testing. Fill the shower pan with water (no drain) and wait 24 hours — if water appears below, the pan membrane has failed. If that test passes, run water at different fixtures (showerhead, handheld sprayer) to isolate whether it's a plumbing connection or tile/grout issue. Check around the mixing valve and shower arm connections, as these are commonly disturbed during renovations.

For New Brunswick homes, this repair typically costs $3,000-$12,000 depending on scope. A simple grout/caulk repair might run $300-$800, but full shower pan replacement with proper waterproofing ranges $5,000-$8,000. If floor joists below have water damage, add another $2,000-$5,000 for structural repairs.

This is definitely professional territory — shower waterproofing must comply with National Building Code requirements, and improper repairs will only lead to bigger problems. A licensed plumber (TIS-licensed) should handle any plumbing connections, while tile and waterproofing work requires experienced contractors familiar with modern membrane systems.

If this renovation was recent, contact your contractor immediately — they should warranty their waterproofing work. Document everything and don't let them dismiss it as a "minor issue" — water damage accelerates quickly in our Maritime climate.

The repair will require a building permit from your municipality or Regional Service Commission if structural work is needed. Don't delay — every day of continued leaking increases the damage and repair costs exponentially.

---

Find a Flooring Contractor

New Brunswick Construction Network connects you with experienced contractors in the directory:

• Pierre Cormier Construction ltd ✓
• MACCALLUM BUILDING SUPPLIES (2009 LTD) ✓
• First united design & construction inc. ✓