Shower Pans And Hot Mopping

Is your shower stall leaking to the room underneath? Forget about caulking, applying sealant to the grout or even re-grouting, the problem is in your shower pan. We are able to resolve the problem in a couple of days. We remove some rolls of tile, demolish all the way to the sub-floor, re-apply a new shower pan, rebuild all the layers and lay new tiles. This is easy as pie.

We have installed so many shower pans that we lost count.

Here you will find schematics for some of the techniques we use. Feel free to call us if you need any work.

Re-grout and Grout Replacement

When setting the Shower Pan Drain, be sure to set the “flat area” of the bottom half directly on the sub-floor surface.

“Blocking” around your shower stall is required to give the Shower Pan a solid surface to sit against, and also protect it from careless tradesmen who might otherwise knock a hammer or other instrument through the Hot-Mop membrane.

“Blocking” is best done with 2″x10″ or 2″x12″ boards cut to fit between the studs.

The “Curb”, also called the Damn, is the area that will serve as the entrance to your shower stall. “Curbs” are usually built by stacking either three or four 2″x4″s on top of each other.

The minimum height requirement for a curb is 4 1/2″, although some people prefer the look of a higher curb and may build it 6″ or even 7 1/2″ tall.

The pan is the part that decides whether the bathroom lasts

Everything visible in a shower is finish. The pan underneath is the building component, and it is the only thing standing between water and the framing.

Which is why a shower that leaks almost never leaks through the tile. It leaks because the waterproofing under the tile was built wrong, and the tile was simply the last thing installed on top of the mistake.

Hot mopping, and why Los Angeles still uses it

Hot mopping builds the pan in layers: hot asphalt and felt, applied in place, turned up the walls and sealed around the drain.

It is a traditional method, it is still widely used in this region, and done correctly it is durable. It is also genuinely skilled work with a short window, and the quality depends entirely on the crew. There is no product to blame if it fails.

Two practical notes. It has to cure before anything goes on top of it, and it produces fumes during application, so ventilation and scheduling matter.

The alternatives, and what each is good at

• Sheet membrane, a bonded waterproofing sheet over the mortar bed. Predictable and inspectable, and the seams and corners are where it lives or dies

• Liquid-applied membrane, rolled or troweled on. Very good at complex shapes and niches, and entirely dependent on achieving the specified thickness

• Pre-formed pans, which are fast and consistent and only work where the size and drain location fit

None of these is better than the others in the abstract. They are better or worse for a specific bathroom, and a contractor who only offers one is telling you something.

Three details that cause almost every failure

1. Pre-slope. The mortar bed under the waterproofing has to slope to the drain before the waterproofing goes on. Without it, water sits on top of the pan indefinitely instead of reaching the weep holes. This is the single most common defect

2. Weep holes. The drain has weep holes so water that reaches the pan can leave through the drain. Grout or mortar packed over them closes the only exit

3. The curb and the corners. Water climbs, and the waterproofing has to be continuous up the curb and turned properly at every corner and change of plane

All three are invisible once the tile is on. That is why the sequence matters more here than in almost any other interior work.

The flood test is not optional

Before any tile goes on, the drain is plugged and the pan is filled with water and left. If it holds, the waterproofing works. If it does not, the repair costs an afternoon.

Skipping the flood test to save a day is how the same defect costs the framing, the subfloor, the ceiling below, and the whole bathroom two years later.

Signs an existing shower is already failing

• A stain on the ceiling below, or on the wall outside the bathroom at floor level

• Loose or hollow-sounding tile at the bottom of the walls

• Grout that stays dark long after the shower has dried

• A musty smell that does not clear with ventilation

• Flooring outside the shower lifting or discoloring near the threshold

By the time any of those show, water has been in the assembly for a while, and the question becomes how far it went: water damage restoration and what causes dry rot and wood decay.

Start with a free 15-minute call

Tell us whether this is a new shower or an existing one, roughly when the bathroom was built, and what you are seeing if something is wrong. In fifteen minutes we can usually tell you whether this is a pan problem, a grout problem, or something that has already reached the framing.

Call (323) 707-4979 to book the free 15-minute consultation.

The Ultimate Pro, Inc. CA License 831700, Class B General Building. Serving Los Angeles, Riverside, Orange and San Bernardino counties since 1996.

Plumbing hidden behind a wall is the expensive kind to guess at. Book a free 15-minute call or call (323) 707-4979 and describe the symptom. We will tell you what usually causes it and what it takes to confirm.

There is usually a video for this. X Plan Nation is our construction channel on YouTube, run by the same team that would build your project and made to explain the trades to the person paying for them.

The Ultimate Pro, Inc. · California contractor license 831700 · Class B general building · 18481 Grand Avenue, Lake Elsinore, CA 92530 · Serving the Inland Empire — Riverside County, Los Angeles County, Orange County and San Bernardino County — since 1996.