Could it possibly be remaining soot from the fire? Was the duct work fully cleaned? We had a furnace blowback a couple of years ago and we put filters over all the vents after a new furnace was installed and hed the duct work cleaned. There was still soot on the filters for a short while after the furnace was replaced.

Hope I'm not double posting but my first reply isn't showing up. The duct work was cleaned and I hope, but don't know, that it was done well. My sister has not reported any evidence of soot anywhere else in the house. The black lines are just on the grout in the two bathrooms.

the picture is blurry so I can't be sure it's not mold, but I would find it surprising that mold or mildew would take hold so quickly in a new bathroom. Maybe a bad batch of grout? I think she should insist the installer come back and check. Usually the mildew occurs when things stay wet or damp and there is not a lot of sunlight. I doubt that is the case here, it's too new and has only been used a few times.

Thanks, divotdiva. We're not getting any support from the contractor, so it will be difficult (maybe impossible) to get in touch with the installer.

Here is a different photo, from the master bath this time. Is it more clear?

If it is bad grout, can it be cleaned or corrected in any way?
I will appreciate your advice because I'm not sure what direction to go to solve this issue---and am concerned that it will get worse.

Did she use the contractor recomended by her insurance company (or did she find/pick out her own contractor)?

I obviously don't know the details, but I do know that "mildew" (pretty much any black fungus) can rear it's ugly little pointed head anywhere and at any time. Unless there's great negligence like missing waterproofing or no supplied ventilation, it's a maintenance problem.

What have you done other than blame the contractor? Have you tried to clean it? Has ALL the grout in the ENTIRE restoration been sealed? Doesn't the fact that it only appears in the two baths mean anything? Here is the most important question: What did the black line do when you sprayed bleach on it?

Have you seen this grout in person? Your second picture almost looks like it is full of holes instead of a substance within the grout line.

I'm with enduring. That second picture appears to be holey grout, not mildew/mold. She needs to take some very good pictures, with dates, and send them to the insurance company and contractor.

If it scrubs off, it might be mildew. But, I suspect it is actually failed/improperly mixed/applied grout.

I will add that the caulking job in the corner doesn't look very well done either (right side of pic).

She used the contractor hired by the insurance company for the cleanup.

As far as I know. the grout wasn't sealed. However, I'll ask her.

She's not tried bleach yet as she wanted the contractor to see it before she tried to remove it. He's not been there to see it and blames maintenance, not installation.

I'm in a different state so I've not seen it. Enduring & Kirkhall I also thought the spots looked like holes in the grout, too, but she says they are black spots, not holes.

JMO - based on my personal experince and that of friends...

(the bad news) some contractors the insurance companies hire will do whatever they can to keep costs down - for the insurance company;

(the good news) she can complain to her agent and the insurance company adjuster and request they intervene. The insurance co picked the contractor; thus, the insurance company bears some responsibility to rectify the situation.

Good luck.

Ask her how they constructed the walls behind the tile. Did they put a waterproofing membrane such as Hydroban, or Redguard on top of the cement board before tiling? If they did not do that, did they put a poly membrane behind the cement board with the overlaps facing down (like house siding laps down). With current tiling tech you need one or the other of these techniques to prevent water from getting into the wall structure. If there is no protection than that will lead to a failed wall and tile system.

If it was me, I would take a Q-tip and dip it in bleach and try one of the areas. Just some remote spot. If it fads then I would suspect mold.

mdln, the contract for repair was between the contractor & the homeowner, so the insurer says it is not its problem. I wish the insurer would be involved because the contractor has done a very poor job in other areas and isn't interested in correcting the problems.

Here is the grout that was used, if that helps in the evaluation of the problem.

I think you need to be really, really persistent with the insurance company (do they want to keep your business?) - as they were the ones who selected and recomended the contractor.

The insurance co can put far more pressure on the contractor, than the homeowner can.

In my situation, when my agent & adjuster were not being helpful, I sent a certified letter to the CEO of my insurance co to get what I needed. The CEO's executive assistant then called me and was very helpful.

mdln, thanks for the advice and encouragement. I'll contact the insurance adjuster and, if that is not is successful, pursue it up the chain.

Does anyone have an idea if this is a bad installation so I can be specific in my complaint to the contractor, the installer & the insurer? .

More details:

No membrane was applied before the tile was installed. Durarock was used. Unknown whether sealer was used.

Do these details suggest an answer to the tile experts?

Was there poly underneath the Durarock? Because that is a legitimate moisture barrier too.

No, enduring, nothing was installed between the studs and the Durarock or between the Durarock and the tile (except the bonding agent).

Then that does not meet standards for tile installation in a shower. There needs to be a barrier behind the CBU or on top of it as far as I am aware. There are several ways and product to do this. Because of their lack of interest in solving this problem I doubt that they are very up on the most modern techniques. But putting poly or tar paper behind the CBU has been done for a long time I think.

Bill V. post some information on this topic mid way down the link I posted.

http://www.tcnatile.com is another site that might provide standards. I couldn't find them. But on the John Bridge Forum they have all sorts of information about proper tile installation.

I wish Mongoct would post on this topic, he is an expert.

Here is a link that might be useful: link about waterproofing shower

If that's the case, you have NO waterproofing in your shower...it was done incorrectly and should be re-done properly, EITHER with poly attached to the studs or the face of the cement board treated with Hydroban, Redgard, AquaDefense, or a similar material. This shower does NOT meet "code." They may try to argue that Durock is waterproof...It's NOT! True, water will not dissolve it, but it's porous, and WILL allow moisture to penetrate it an eventually rot out the wall studs.

With this level of "competency," I have serious doubts if they bothered with a "preslope" under the pan liner, either...but that's just a guess...

If your area requires Building Inspection Approval, you might contact them for advice and your concerns. Certainly more ammunition for you if you need to deal with the Insurance Company. If THEY sent/provided the installer to you, a good case can be made that they DO bear responsibility for a properly built, code compliant shower.

I'm quite sure that they don't want to get into a fight with the local Building Code Authorities.

Enduring and StoneTech, the village in which she lives did a number of inspections and various other aspects of the work had to be redone to pass inspection. I'll ask my sister to talk with the inspector to see if he examined the bathrooms and waterproofing before the tile was installed. This sounds like the black spots are just the beginning of a major water issue.
I've been posting on the John Bridge site but haven't received an answer yet. I'll read mongoct's link.
Thanks for your help.

Did you post it on the "Tile Forum/Advice Board?" I don't see your post or your name there. You might try again, if not.

I think the advice there will pretty much reflect the responses here.....

Thanks StoneTech for commenting. Great to hear from a professional on this topic.

BTW that's not mongct's link, it is someone else's but it includes several comments by Bill V. who is a tile professional.

StoneTech, I was over on JB earlier this morning to try and find a specific link or direction to a code for shower water management. I couldn't find anything to back me up regarding "standards". So I went to the Tile Council of North America, and couldn't find a specific directive. I wanted to include the resource in the comment I made this morning.

If you could point me to that I would be so appreciative.

StoneTech, I've been posting to the John Bridge Ceramic Tile Advice Forum where CX is the moderator-at-large. Isn't that the right place? The title of the thread is "Recent tile install now has black in grout - help" under nancyaustin.

enduring, I'll look at the thread now. I agree that StoneTech, bill-vincent and mongoct are the tile gurus! .

From reading the link, I'm concluding that either a plastic covering should have been installed over the studs before the Durarock (Durock?) was installed OR after the Durarock was installed, a membrane should have been installed over the Durarock or some sort of waterproof product should have been painted all over the Durarock.

Is my understanding correct?

Yes. Except, as far as I know, I think tar paper could also be used instead of plastic over the studs, (ie on outside walls).

Basically you are trying to prevent water from coming in contact with the studs, and or studs/insulation. There are two places you can place the waterproof barrier, you should not place both, just one or the other. Either underneath the durarock or over it. The Durarock itself is NOT waterproof!

Nancy...found your post in the "Cleaning" section. They may move it to the advice section as there is more in play here.

Anyway, I looked for a reprint of ANSI 118.10 but didn't immediately see one, so I posted this on your thread. Keep checking it...

Enduring~Good link on the subject. You keep up with the thread along with Nancy....someone should have a link to the ANSI code......

Stone Tech, thank you very much for moving my thread to the right area of John Bridge. The contractor hired the tile installer, not the insurer. I got the name of the contractor because the insurer hired the company that did the immediate repair after the fire. The insurer didn' hire the company for the restoration work. The homeowner did---the insurer paid the homeowner for the repairs. The contractor says the tile was properly installed but that my sister wasn't properly maintaining the tile. The contractor has not looked at the tile to check out the black line issue. I'm explaining this so that you'll understand why the insurer is likely to say that the insurer will not be involved. The insurer has made it clear that it is not a party to the contract between the homeowner & the contractor. But, I'll call the insurer tomorrow to see if it will decide to get involved. My sister will contact the village inspectors tomorrow to see if they will get involved.

Thanks again, Stone Tech, for putting the right question to the John Bridge people.

I appreciate your help and yours, too, enduring!

Right now you are just focused on the repair but......
In my state there is a Contractors State Licensing Board. See if your state has one too and file a complaint. For my state there is a web page to do it.

Thanks, emmarene. I'll see if there is one in Illinois.

While I agree that there are installation problems if there's no plastic liner behind the Durock or membrane painted over top of it....

...that would cause mold/mildew to grow behind the Durock, not on top of the tile, no? Especially as it's only been 6 weeks. Hardly enough time for enough water to seep through the Durock onto the studs, rotting the studs, and then working its way back through the tile.

I think it points more towards insufficient drying out after showers. I'd look more closely into the CFM of the vent fans and how long they're being left on.

That could very well be....but the incompetence of the installer leads to many other critical issues...."long term" would be foremost in my mind. A short-term fix is just fine, but what about three years "down the road?"

(Glad you got some advice at the JB Forums...)

Am also in IL, this is another resource (IL Dept of Insurance) you can use to try to get your insurance company to step up and assist you.

Since the insurance company selected the contractor, they have a responsibility to refer you to qualified contractors. That includes qualified to select/use appropriate subcontractors.

https://insurance.illinois.gov/Complaints/hard_copy_PC_Complaint.pdf

Here is a link that might be useful: IL Dept of Insurance - Property/Casualty Consumer Complaints

Thanks, mdln, but there is a misunderstanding. The homeowner hired the contractor. The insurer hired the contractor only to do the original board up after the fire. That's how we came across the contractor. The contract for the restoration is between the homeowner and the contractor. The insurer did not select the contractor to do the restoration, I doubt the insurer can be held responsible.

Thank for the clarification.

Did the insurance co offer any different restoration contractors? As you know, some clean-up services also offer restoration. Perhaps, that was the intent of the insurance co (that the insured would use the same co)?

Insurance co usually refer the insured to one or more restoration contractors. Were these not used?

The insurer suggested another company, one that the adjuster said was "next up on the list for referral." Apparently, contractors pay to be on a referral list. The insurer would only suggest one company and not several to select from.
We went with the company that was hired by the insurer to do the clean up because we thought this company (it is a large one) would have less of a tie to the insurer and would more likely listen to the homeowner. We tried to do a due diligence for the company, talking with 3-4 previous fire damage customers and my sister looked at one or two homes of these customers. The referrals were all quite positive and the homes looked great.
However, the work done in those home and for those customers was not by the same project manager who was assigned to this project. The project manager for my sister's house has not done a good job and several of his subs have been bad. In addition to this tile problem, there are other problems. The shingles on the roof are bubbling up and new flashing was only put around part of the chimney. The backsplash in the master bathroom has a 1 inch gap between the backsplash and the wall that he proposes to cover with quarter round. The casings of three doorways in a hallway are all of different heights. I think you get the picture.

I should clarify that the company that was hired is a restoration company and a clean up company and it appears to be a large company. In other words, we didn't hire a company that did only clean up to do the restoration work.

This sounds like a very big problem all around. I have no experience with any of this kind of thing. Doesn't the company even want to take a look? Are there pictures of all these poor jobs to share with them?

I hope we gave some decent advice at JB Forums...

Enduring, Stone Tech & mdln, thank you very much for your help and concern. My sister checked with the village today and learned that it does not require waterproofing---they seem to think that Durarock is sufficient without waterproofing. I talked with the insurance adjuster and, although he was sympathetic to this and the many other problems with this contractor, he said that he doubted that the contractor would listen to him.
Given some of the responses on the JB forum, I'm not sure that I can tell the contractor, if not waterproofing was installed, that it was a substandard installation. There seems to be a division of opinion on the JB forum----if i'm misinterpreting the thread of conversation, though, please tell me. The contractor has been told that the showers were squeegeed after use and that the exhaust fans used also, so he needs to investigate. He made no response to day so I don't know what he'll do. He's done very little to correct other problems, so I am not hopeful.

Squegeed or not, Durock is NOT waterproof! Water can and WILL get behind it and rot the studs. Just because Durock doesn't "fall apart" in the presence of water means NOTHING!

A properly built shower MUST have either plastic liner attached to the studs OR a "Surface Applied Membrane" attached in the face of the Durock!

These membranes meet ANSI code 118.10.

Examples are "Redgard, Hydroban (from Laticrete) or Kerdi (from Schluter.).....as well as others.

If the Inspectors don't realize this, they are ignorant and you should go to see the Head Inspector and voice your concerns. This IS "code" and should NOT be ignored.