Nampa, Idaho

Leaking Shower Pan Rebuild — Nampa, Idaho

A stain on the ceiling below the bathroom traced to a mortar-bed pan with no usable membrane. The wet area was stripped to framing and rebuilt as a fully bonded system.

Rebuilt shower pan in a Nampa, Idaho bathroom at the waterproofing stage, with bonded orange membrane, banded corners and a bonding-flange drain before tile — Nampa pan rebuild at the waterproofing stage — membrane bonded across floor, curb and walls, corners banded, drain set and flood tested before tile. Representative photography of the work described — being replaced with job-site photos from this project.

Project data

Location: Nampa, Idaho (Canyon County)
Project type: Shower waterproofing and pan rebuild
Approximate wet area: About 30 square feet
Duration on site: Roughly two weeks, plus drying time before rebuild
Tile: Reset with new porcelain wall tile and mosaic floor
Waterproofing: Bonded sheet membrane, banded corners, bonding-flange drain

Existing condition

A 1970s bathroom with a tiled shower that had been re-grouted repeatedly. The ceiling in the room below had a brown ring that reappeared after painting. Demolition found a mortar bed sitting on a shot pan liner, with the liner cut short at the curb and no protection at all where the drain met the bed.

What the homeowners wanted

Stop the leak permanently rather than chase grout, and rebuild in a way that could be documented and inspected.

Scope of work

Full tear-out of tile, mortar bed and pan liner to framing and subfloor
Moisture readings and drying of the framing before any rebuild
Replacement of the damaged subfloor section and one bottom plate
New bonding-flange drain assembly
Sloped base, bonded sheet membrane over floor, curb, corners and walls
Flood test before tile went on
New porcelain wall tile, mosaic floor and full silicone at every change of plane

The problem we hit

The framing was wetter than it looked. Surface material was dry to the touch but meter readings at the bottom plate stayed high two days after demolition, which meant tiling on schedule would have trapped moisture inside a brand-new assembly.

How it was solved

We held the schedule, ran air movers and re-checked readings daily until the framing was back in range, then replaced the plate section that stayed elevated. It cost several days and it is the reason the rebuild is dry. We flood-tested the finished pan before a single tile was set, which is the only point where a pan can be proven rather than assumed.

Materials and systems

Waterproofing: Bonded sheet membrane with banded seams, corners and curb wrap
Drain: Bonding-flange drain matched to the membrane system
Wall tile: Porcelain field tile
Floor tile: Porcelain mosaic with tight joint spacing
Verification: 24-hour flood test before tile

Where to go next

Questions about this project

Could this shower have been repaired instead of rebuilt?: No. Once the pan liner has failed, everything above it is sitting on a system that cannot be repaired from the finished side. Re-grouting a failed pan buys weeks, not years.
How do you know a new pan is watertight?: A flood test before tile. The drain is plugged, the pan is filled and it sits. That is the only stage where a pan can be proven, which is why we never skip it.