HUMP in Kerdi shower pan drain membrane

[Bigtime57]

Installed a Schluter Kerdi shower pan and didnt notice until laying out floor design that I have a small hump in my drain membrane ring.... can barely feel it but when laying the tile out it rocks back and forth .....already did a flood test and it was successful ....just trying to figure out how to remove that hump before laying floor without screwing everything up

[Kman]

Welcome to the forum, William.

So can you clarify exactly where the problem is? Is it over the actual drain flange? If so, is the flange itself causing the bump, or excess mortar between the membrane and flange?

Or is it somewhere else on the floor?

Is the floor a foam tray or mud?

[Bigtime57]

it is between the drain flange and the top membrane ring its about in the middle of the wide membrane ring that comes with the floor pan kit... its h ard so im sure its mortar.... i hate to cut into the membrane and remove the excess mortar ....but i can if that needs to be done and repair it with a piece of kerdi.... and its not huge but you can tell its there and since that the area needing to lay towards the drain made me concerned .

[Kman]

Unfortunately, there's really no other way than to cut the membrane around the bump. You'll scrape loose all the excess mortar, and apply a patch that overlaps the cut by two inches all the way around.

[Bigtime57]

Ok Thanks for the help ......

Absolutely nothing like this site for decades of Knowledge !!!!

Thanks again

[Lazarus]

Redneck fix? Take 3 pound maul and give it a whack. Might "powder" the hump! LOL

[Kman]

Might also crack the drain flange.

[Lazarus]

Yeah, possible but unlikely....

[Bigtime57]

i cut a slit in the membrane and removed the motar ....wasnt as much under there as expected but got it smoothed out and placed a piece of Kerdi over it letting it overlap at least 2" all around ......

[Kman]

[Bigtime57]

I didnt notice how bad a subway style tile was chipped until I started grouting and it really stands out .... my question is since its next to the niche and the schluter trim ...whats my chances of cutting it out and not screwing the whole niche trim up ?

[cx]

Welcome, William.

Please keep all the project questions on one thread so folks can see what you're working on and what's been previously asked and answered. A moderator can give it a more generic title any time you'd like to suggest one.

Chances of removal? 100 percent. Chances of removal without damage to the Kerdi waterproofing? Far less, but depending somewhat upon how long ago your installed the tiles.

My opinion; worth price charged.

[Bigtime57]

understood on the threads... my bad ...

The tiles have been up around a week and 1/2 , my friend says leave it alone (her house) no one would ever notice it ...BUT I notice it now and cant get it out of my head .....

[jadnashua]

It's highly likely that you'll pull the fleece off of the Kerdi when trying to remove the tile. Thinset does NOT stick to Kerdi...it holds by flowing around the fleece, then curing to lock it in place...there's no bond to the material itself.

A nailset, hammer, eye and body protection, and crack the tile AFTER removing the grout, and you can then likely get the tile off. At 10+ days, the thinset has cured most of the way, but still not fully cured (industry rates full cure at 28-days, but it actually continues to cure for decades). Depending on how good of a job you did, if the tile comes off without tearing off the fleece, you could use a rubbing block to smooth out what's left.

KerdiFix would bond the new tile in place if there's no fleece, but I'm not sure how well that would work long term.

You might try a grout colorant, and put it on the tile's edge to help mask it. Or, just leave it.

These kinds of fixes are best made as you're installing the tile. Dealing with a surface membrane complicates things as cutting out damaged Kerdi (or other similar products) means it's really hard to get a good seal between what's left and the new patch.

Call Schluter to see what they say.

[cx]

I agree with your friend, William.

No, you will never un-see it, but if she can, leave it alone. Chances of changing it from an aesthetic consideration to a technical problem are high.

My opinion; worth price charged.