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Calcium carbinate shower drain build up

I've had a problem with calcium carbinate (my local health department confirmed my claim that this material is calcium carbinate) build up in my shower drain. This deposit builds up below the point where the membrane is secured to the drain. This is a new home that's only 8 months old and it's a tile shower and shower pan. During that time I've scraped out the calcium three times from the drain which is totally coated with this deposit. Along with this delema, my shower pan never seems to dry out as evidenced by the grout always being wet along the edge of the shower floor and up an inch or so in the grout on the wall and deposits accumulating there too. I have a watersoftener that seem to be working since I'm not having any hard water deposits anywhere else.

I've removed the tile and pan down to the membrane around the drain in order to make sure that the seep holes were ok and they are. I also have a Warmly Yours 24 volt infloor heating mat in the shower floor (which is now ruined after doing the above).

Any ideas why this is happening? Is it possible that the in floor heating element is causing this (warmly yours says no)?

Thanks for your help.

Re: Calcium carbinate shower drain build up

Just a guess here, is the fall on the floor or drain taking the water away properly. If it lies and dries it will leave a deposit.

Re: Calcium carbinate shower drain build up


I'm having a similar issue. Did you ever find a solution? I have a 3 year old shower (tile and marble) that calcium is building up and blocking the weep holes. The water is then backing up under the tile floor but above the membrane and entering the wall outside of the shower.

I also have a heated floor, but it's not in the shower, but right outside. Other areas that I have considered, the tankless water heater is causing the calcium to leach out of the water. Or a chemical reaction with the cleaning or shower products we use.

This is driving me crazy! Thanks for any advice


Accents By Rob
Re: Calcium carbinate shower drain build up

I am a professional Ceramic tile contractor with 25+ years experiance. I also have the same issue with a drain plupping itself with stlagtites of calcium. we have tested thier water its good and tested substance in drain it contains calcium 278,000 mg/l , barium2060 ppm, and magnesium 274 Mg/l. Im at a loss once all the tile products ( concretes) have cured they chould have no calcium in them that could be released??? correct??

Any help would be great This Tile guy is also stumped

Re: Calcium carbinate shower drain build up

I have a customer who empties a small bottle of CLR down the shower drain every time he leave for travel, letting it set there for a week or longer.

His drain clogged from 2" down to a pin point, flooding the third floor. After chipping away with a screw driver and flushing the chips away, the CLR did a great job of dissolving the remainder. It will foam up a few times and repeated applications are needed the first time around.

After the first flushing, a quart sized unit will work when used regularly.

Re: Calcium carbinate shower drain build up

My guess would be a high content of lime was used in the cement or grout.
Lime used in cement will lay dorment ( it's called free lime )high contents of lime in a damp area will remain in a puddy stage and migrate with the water when the water evaporates the Calcium Carbonate remains on the surface. The same thing you see on the exterior of a building with brick or stucco that has a water leaking behind it they call this effervesence.Have the grout checked for lime content.

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