Shower pan waterproofing in Spokane

Signs of a leaking shower pan

• Floor grout stays dark long after the shower dries.
• The curb feels soft or moves under your foot.
• Flooring outside the shower swells or lifts.
• A stain appears below an upstairs shower.
• A musty smell returns after cleaning.

New caulk or grout may close a visible joint. It will not repair the waterproof layer below the tile.

Sheet membrane, liner, or hot-mop

Sheet membrane. A waterproof sheet sits directly behind the tile and seals to the drain. Schluter Kerdi is one example. Water reaches the membrane and runs into the drain.

Liner under mortar. A rubber or vinyl liner sits below a sloped mortar bed. Water that enters the mortar leaves through weep holes in the drain. Blocked weep holes can keep the mortar wet.

Hot-mop. Layers of asphalt and felt form the pan below the mortar and tile. A cracked hot-mop pan cannot be patched through the grout. The shower floor has to come out.

Ask which system the installer uses and how it connects to the drain. A coating over old grout is not a new shower pan.

Why an older shower pan fails

Liners can split at corners. Hot-mop can crack with age. Weep holes can fill with mortar or mineral buildup. Each problem traps water below the shower floor.

If the floor and walls need to come out, the opening can be rebuilt as a custom tile shower.

Water below an upstairs shower

Stop using the shower if a stain appears on the ceiling below it. Tell the installer whether the stain grows after the shower runs. That detail can help separate a pan or drain leak from a supply-line leak.

Read what affects shower pan and tile cost. Wait to replace bathroom floor tile until the leak is fixed.

Common questions

Can a leaking shower pan be repaired without removing tile?

Usually not. The pan sits below the shower floor, so the floor tile and mortar normally have to come out. The wall tile may stay if the walls are dry and the new pan can tie into them.

How do I know if the leak is the pan or the plumbing?

Watch when it happens. A leak that only shows up after showers points at the pan or the drain. A leak that shows up when nobody has showered points at a supply line or the valve.

Should a new shower pan get a flood test?

Yes. A flood test holds water in the finished pan before tile covers it. Ask the installer how long they test and how they watch the water level.