Sheet membranes, liquid-applied coatings, plastic liners and hot mop all waterproof a shower floor, and all of them work when they are installed properly. We build hot mop pans because in ten years of opening up failed showers, it is the method we have seen last the longest.
Start with the honest part
Every one of these systems works when it is installed correctly. Most shower failures are not caused by the brand of waterproofing; they are caused by a missing pre-slope, an unsealed corner, or a nail.
So the real comparison is not "which product is best" — it is which system is most forgiving of the way a real jobsite behaves, and which one is being installed by someone who does it every day.
Where we stand
There are many ways to waterproof a shower. The one that lasts the longest, in what we have seen, is hot mop. That is a ten-year opinion formed by being called out to fix other people’s pans, not a manufacturer’s claim.
It is also the only thing we do. We are not a remodeling company that also waterproofs; we build shower pans and nothing else.
The honest weaknesses of hot mop
- It smells while it is going in. Hot asphalt does, and we say so up front rather than after.
- It is heavy. On a floor that moves or feels like it could give way underfoot, it is the wrong choice, and we will say so.
- It needs a specialist. It is not a system a general remodeler picks up between other trades.
- It cannot be rushed. The flood test takes the time it takes.
What plastic liners get wrong most often
The most common failure we are called out to on a liner is the corners. Somebody puts a plastic liner in and does not secure the corners well enough, and water makes its way out through those little gaps.
It is the same lesson as everywhere else in this trade: the corners and the slope are the job. Everything else is detail.
How to judge whoever you hire
Whatever system you choose, these questions separate people who do this properly from people who do not:
- What is the pre-slope made of, and does it go in before the waterproofing?
- How are the corners reinforced?
- Does the membrane turn up the wall and over the curb?
- Will there be a flood test, and who runs it?
- Are you licensed, and will this pass inspection?
Common questions
- Is hot mop better than Kerdi or RedGard?
- All of them work when installed correctly. In ten years of repairing failed showers, hot mop is the system we have seen last the longest, which is why it is the only one we build.
- What is the most common cause of shower waterproofing failure?
- Not the product. It is a missing pre-slope, corners that were not properly sealed, or a nail through the membrane after the work was finished.
- When is hot mop the wrong choice?
- On a shower floor that moves or feels like it could give way underfoot. The material is heavy, and we will tell you rather than mop it.
About Figueroa Shower Pans
Figueroa Shower Pans waterproofs shower pans across San Diego County, based in Escondido. Francisco Figueroa has worked in the trade for 10 years, and shower pans are the only thing the business does — no demolition, no tile. CSLB License #1092967 · C-61/D-12, with general liability insurance and workers’ comp.