I have been researching Kerdi Flood testing procedures online and came across this thread over on John Bridge's tile forum.
Here is the link. http://www.johnbridge.com/vbulletin/...ad.php?t=87445
The moderator there who answered the question is like Jim an engineer and one would think they have a solid understanding of building science. BBCAMP replied that the water level in a Kerdi flood test needs to be topped up after one hour. He goes on to state that if it leaks more than 1/8" you have a leak.
I worked out the math on a 1/8" drop oin water level for a 3'x4' shower and it equates to more than 4 bottles of wine in a 3'x4' shower.
This can't be correct? Can it? Of Course not.
Here is a shower of mine sitting pretty on hour 48. No loss of water and no drop in water level.
I use a tipped coin method of marking these Kerdi Shower flood test to make sure we read the exact water level.
I have never seen drops like this using Noble Seal TS, Kerdi, Hydro Ban or any of the liquids we use. What do you Kerdi men out there think? IS this common on a Kerdi Shower flood test? If so what are you doing wrong?
I emailed Schluter today and hopefully in a weeks time I can get an official reply back from them.
What do you think Jim? Would you say 1/16" level drop is OK? 3/16" drop? 3/32" drop?
I measure the water levels exactly when doing flood tests here in Vancouver and we measure for evaporation when needed?
Never have I had to "Top Up" a flood test.
You can see even Schluter showcases a flood test with their new installation video.