keytermite

Looking for some input. We are a Termite Control company in California. I have recently run into tiled/marble stall showers on 2 separate properties (new construction) where the showers failed our state required shower test during our inspection. We are required to test by plugging the drain and filling the base to within one inch of the top of the finished dam and wait a minimum of 15 minutes before checking for leakage. Leakage from the base of the dam occurred before reaching the minimum water level or the 15 minute mark. Both contractors insisted that the water level of our required test was too high and holds a water level that is above the actual waterproofing of the dam. Both showers when tested with one to two inches of water in the pan for over 24 hours and did not leak. Both contractors stated that the framed dam height was the minimum requirement of 4 1/2 inches (3 rows of 2X lumber) and that the remainder of the build up (7-8 inch dam height) was dry pack mortar below the tile. Tile contractors I have spoken to say that a mortar bed of 3 inches on top of the rough threshold is unheard of. I am looking for minimum framing or dam height requirements for the rough threshold and any information on standard post construction water tests performed out there. Without further information, I may have to tear out the tile on the face of the dam to verify the height of the waterproofing to the frustration of the homeowner and contractor. Thanks for the help. Any advice would be appreciated.

cleveman

If I'm not wrong, you want to know what is customary as far as how far up the wall/curb to go with the waterproofing membrane. And you want to know the average curb height?

The curb height will depend on the size of the shower pan itself. I think the minimum height you can go with the sand/portland mix is 1 1/4". So you want it 1 1/4" thick at the drain, plus 1/4" per foot to the curb/wall. So in a 4x4 shower, you go 2' to the wall/curb, so add 2x1/4"-1/2". So it needs to be 1 3/4" thick at the curb/wall. Now put down the membrane and do it all again, and you are up to 1 3/4" x 2= 3 1/2" at the curb/wall. So you might want a 4 1/2" high curb. Add 1/2" for every additional foot of shower floor space. Fore example, a 6x6' shower would require another inch.

I was taught to put the membrane up and over the curb.

As far as verifying what was done, the water test has to be done beforehand. And there should be nothing wrong with taking a few fotos of each job. Furthermore, the same standards should apply to every job. You don't do a job differently depending on the day of the week.

As you mentioned, I think 4-6 inches up the wall is standard. I've seen people put the membrane up about 2' and I don't know what they were thinking.

As far as the water test, I don't care what anyone says, you should be able to fill the pan until it is overflowing onto the floor. It shouldn't leak until it overflows on to the floor. Obviously you are not going to waterproof the entire bath or 2nd story floor.

mdshunk

If you are required to test them in the manner you described, then it really doesn't matter what the builder says is normal, does it? It fails the test that the state requires of a termite inspector. End of story.

The builder, even if he complied with the standards related to building a shower (it probably doesn't, but that's another issue), has failed the required shower test for a termite inspection. Sorry about his luck. You have fulfilled your duties as a termite inspector, and the builder can go fight with someone else. You just report what you observed.

jarvis design

Unfortunately, your story does not surprise me after reading how some showers are built in California.

Now, Had this been a properly installed Kerdi shower, you would not have any leaks - yes, even if the entire pan was filled to capacity!!

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dakzaag

Could someone help me understand.

What does termite control and shower base holding capability have in common.

Not looking for a fight, it just seems that these two fields couldn't be farther apart.

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cleveman

Dakzaag,

Water

Bill_Vincent

The membrane is supposed to go up a minimum of 6" higher than the top of the curb. But I have a question for you. Are you sure it was leakage, and not seepage thru the grout joints into the pan?

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keytermite

Thanks for the input. I did see your web site. Very interesting. I will be looking into the Kerdi process further.

keytermite

Good question, I get asked this one often. Shower leakage is considered a "condition deemed likely to lead to infestation or infection" by wood destroying pests or organisms. Basically, if wood gets wet, it will eventually rot or become infested by a wood boring insect.

keytermite

Good question, I get asked this one often. Shower leakage is considered a "condition deemed likely to lead to infestation or infection" by wood destroying pests or organisms. Basically, if wood gets wet, it will eventually rot or become infested by a wood boring insect.