Shower floor not drying proportionally

Is there a way tool to detect if moisture is being trapped underneath the pebble tile floor of a shower floor? No standing water, but it simply takes days for the grout to return to the same color as the other areas that seem to be drying faster. New shower pan, new hot mop, cement and pebble tile.

Use sealer on the stone and grout and you won’t have that problem.


My contractor says that the sealer is built into the grout. He doesn’t know why.

But another contractor working on my kitchen took a look and started knocking on the shower floor. Where the area looks like it is not drying, the area sounded hollow. Where it looks dry, it sounded solid. Does that sound like a good principle?

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Ryan sealer isn’t built into the grout. If it is the sealer is nothing like the stuff you apply after the shower is completed. If your grout was sealed the water would bead up and not saturate the grout.


That sounds like You have a problem, A hollow sound often indicates loose tile or mortar bed…


Your contractor probably used a polymer modified grout and if everything worked as planned a sealer would not be necessary . Topical sealers such as Martin is talking about can aid in maintenance and can help keep the grout from absorbing moisture. This type of sealer will wear off given time and would need re-application. The hollow sound in areas of a tile floor is a red flag . I would call Your tile guy back,


Describer the shower. There are many types.

In a stall shower, the plumbing code requires the floor to be sloped (1/4) of an inch per foot in order to carry the water effectively to the drain.

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  • After two days it still looks like is has not dried completely. When knocking on the darker area, it sounds hollow and the dry areas sound solid.

Step 1. Hot Mop: The company, “Shower Pan Man” from Vista, Ca., used tar roof shingles to create the slope (stair stepping them down to the drain from all four sides). Then they did the hot mop.

Step 2. Different team for the floor tiles. They did the cement, tile and grout.* Grout provided by contractor

@ryoung7 Floor and Decor: Pebblino MosaiciDolomite Palissandro Honed Pebble Mosaic ( SKU 100695576 )


Did the builder use this styrene foam crap? There is nothing better than a copper pan and mortar bed.


No copper base; One company did the Hot mop. Another team did the cement, tile and grout.

Team1. Hot Mop team: The company, “Shower Pan Man” from Vista, Ca., used tar roof shingles to create the slope (stair stepping them down to the drain from all four sides). Then they did the hot mop.

Team2. Installers for the cement, tile and grout.

roof shingles for a shower pan is a brand new one to me of of course Im kinda new and You are from California :wink:.


Yup, they mopped up your money. I personally have never seen this method. Do you smell it when the shower gets hot?

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The hot mop is a classic approach. Search YouTube. The Shower Pan Man has been in business for over 20 years. My plumbers say he’s the best: they see the company all the time on job sites. My brother in LA also had his 1930s shower redone with a hot mop. Never knew that until I just mentioned I had just had mine done.

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Where are you located?

The application and method is probably sound from reading what you described. However if you are getting these problems I imagine the install was not done correctly.

Seems like it. It appears to be mostly regional and that is likely why I have not seen it. Looks like a solid approach to shower pans. If you determine the problem and the solution, please come back and share.

Hot mop shower pan is done using melted roofing tar and felt, not roofing shingles. But it is an old school way of doing it before liners became available and products like Red Guard. Some still swear by the method, but how many new kids can handle hot tar? You kidding? :laughing:


They use composition shingles first for slope then tar, then felt. 5 layers of tar, 3 layers of felt paper, 15 lbs. felt.

Yea it’s old school: Pitch/Tar: Noah’s ark and Moses’ basket. :slight_smile:

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That’s a great response. Thank you, Dustin. The tile guy thinks it needed another seal on it. We put a high pressure fan on the areas today, and it has slowly dried out to the color came almost to the other areas that were the proper color. He rolled on a coat of CUSTOM sealer, and said wait a day.

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