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Dark grout due to insufficient mortar??

HU-659037316
5 months ago
last modified: 5 months ago

We are having an issue in our recently remodeled master shower where sections of grout are not drying out and staying dark. We’ve been using the shower ~3 months but the issue started after the very first shower; it spreads with each shower and now affects not only the shower floor but also the curb and wall grout. Our contractor and 3 others (second opinions) are stumped based on visual inspection with the naked eye. The only thing they commented on was that grout was used at the changes of planes, which I have already requested be removed and replaced with silicone/caulk to be in accordance with TCNA guidelines.


The obvious possibilities (preslope, weep holes, grout mix, sealant) have pretty much been ruled out.


The problem in areas does dry out with a hair dryer, only to come back. Some areas do not dry out…assuming that means perhaps a lot of water behind?


The problem affects 3 different types of grout and 3 different surfaces—plus both sealed and unsealed grout—so I figure one common denominator is the mortar. I was looking back at progress photos (see below), showing what appears to be spot bonding and certainly not 95% coverage; unfortunately I didn’t know this was against standards at the time. After Googling, I found a few websites describing our exact grout problem as a result of insufficient mortar so I’m confident this may very well be the root of the problem (https://www.ceramictilefoundation.org/blog/insufficient-mortar). Plus, we had several issues with the tile/grout work already, including two hallow-sounding floor tile, so this “fits.”

Our contractor has repeatedly stated it can’t/shouldn’t be puddling water, because it would drain down due to gravity. (Can anyone comment on this?)


I did buy a pinless moisture meter with masonry setting on Amazon which is giving high readings, but not sure how reliable it is?


Finally, please know that I did my due-diligence when choosing our contractor. We went with one of the most highly reviewed and highly rated remodeling companies in our area (licensed in our state) with countless recommendations from neighbors and on community forums.


We are so frustrated and just desperate for answers. Any insight is greatly appreciated.









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