Ceramic Tile Advice Forums - John Bridge Ceramic Tile

Welcome to John Bridge / Tile Your World, the friendliest DIY Forum on the Internet


Advertiser Directory
JohnBridge.com Home
Buy John Bridge's Books

Go Back   Ceramic Tile Advice Forums - John Bridge Ceramic Tile > Tile & Stone Forums > Cleaning, Restoration and Sealing

Sponsors


Reply
 
Thread Tools Search this Thread
Old 01-19-2018, 11:04 AM   #1
wopachop
Registered User
 
Join Date: Feb 2007
Posts: 280
Why is this grout black along the corners only?

Hello everyone learned a ton from this forum over the years. Im stumped on what is causing grout to turn black. At first i thought the weep holes were plugged, and water under the tiles is darkening the grout.

Then i thought its just mildew and needs to be cleaned.

I cleaned with Miracle Heavy Duty acid cleaner. Not a single spec of black color comes off. The scrub pad i used did not pick up any black color either.

When i get the grout wet, it does not change color.

Why is the black color just along the corner edge? Shower is located in southern california where hot mop shower pans are popular. Can it be tar related? Black magic maybe? Mildew under a layer of grout sealer?

Thanks for any advice on the cause and the correct repair.
Attached Images
    
__________________
Tony
wopachop is offline   Reply With Quote
Sponsored Links
Old 01-19-2018, 11:08 AM   #2
Houston Remodeler
Pondering retirement daily

STAR Senior Contributor

 
Houston Remodeler's Avatar
 
Join Date: Oct 2009
Location: Houston Texas
Posts: 27,622
Tony,

Your shower pan is holding more water than it should, not letting it dry as normal.

1- Do you have any idea if the hot mop was sloped towards the drain?

2- Do you have any idea if there is pea gravel (or similar) around the drain?

3- I'd be looking at removing the shower floor and having it properly re-set with the right drypack mixture, gravel around the drain, and caulking at the changes of plane.

4- Is the curb showing any signs of puffing? expansion? cracked joints & tiles not aligned?
__________________
Paul1

For when DIY isn't such a good idea...
Houston TX area Kitchen & Bath Remodeling


http://CabotAndRowe.com
Houston Remodeler is offline   Reply With Quote
Old 01-19-2018, 11:29 AM   #3
wopachop
Registered User
 
Join Date: Feb 2007
Posts: 280
Unfortunately we know nothing about the construction of the shower. Can i pop off the shower drain cover and possibly get some clues?

I can look closer at the curb next time over there. While trying to clean i did not discover any cracks in the grout, or any tiles that appear to be coming loose.

If its water under the tiles then why is the black color only along the edges? Wouldnt the entire floor show signs of dark grout or mildew?
__________________
Tony
wopachop is offline   Reply With Quote
Old 01-19-2018, 12:05 PM   #4
Houston Remodeler
Pondering retirement daily

STAR Senior Contributor

 
Houston Remodeler's Avatar
 
Join Date: Oct 2009
Location: Houston Texas
Posts: 27,622
Yes there is water under the tiles, sammiched between the tiles and the vinyl liner is a 2 inch thick layer of drypack. (cement)
__________________
Paul1

For when DIY isn't such a good idea...
Houston TX area Kitchen & Bath Remodeling


http://CabotAndRowe.com
Houston Remodeler is offline   Reply With Quote
Old 02-16-2018, 10:30 AM   #5
nesc39
Registered User
 
Join Date: Apr 2014
Posts: 4
So your saying he has 2.5 of pan water that is only affecting the highest part of his floor?
__________________
Repid
nesc39 is offline   Reply With Quote
Old 02-16-2018, 07:21 PM   #6
lati_cz
michal
 
Join Date: Nov 2008
Location: sunnyvale, ca
Posts: 1,886
isn't is tar?
__________________
Michal
lati_cz is offline   Reply With Quote
Old 02-18-2018, 11:28 AM   #7
Davy
Moderator -- Mud Man
 
Davy's Avatar
 
Join Date: Jan 2003
Location: Princeton,Tx.- Dallas area
Posts: 28,956
It's hard to say, without knowing more about the installation, all we can do is guess. Mold is what we usually see but I don't think it's mold this time. If it were mold, the cleaners you used would have at least removed some of the black. I believe it's the oils in the tar soaking into the grout. I've worked around hot mop pans before and have never seen this happen, maybe someone else has.

If the studs aren't notched to allow the pan to be recessed back, the pan will stick out almost as much as the cement board. I have tore out showers where the installer stuck the tiles right to the pan liner along the bottom. My guess is that's what he did, stuck the tiles to the hot mop along the bottom.

If that's the case, the grout would need to be cut out and replaced in the black areas. Care would have to be taken not to cut too deep and cut into the pan.
__________________
Davy

www.davystephenstile.com
Davy is offline   Reply With Quote
Old Yesterday, 11:16 AM   #8
John Bridge
Mudmeister
 
Join Date: Mar 2001
Location: Houston, Texas
Posts: 66,780
Send a message via AIM to John Bridge
As to the water affecting only the highest part of the floor, that happens to be the last place to dry out in any shower no matter how it's built. . . unless the shower is towel dried after use.
John Bridge is offline   Reply With Quote
Reply

Stonetooling.com   Tile-Assn.com   National Gypsum Permabase


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
just installed black granite tiles and black grout is white in some areas. Jmarie Cleaning, Restoration and Sealing 6 07-19-2011 06:03 PM
30 yr old black slate with dirty black grout cbell50 Cleaning, Restoration and Sealing 4 11-22-2009 07:25 PM
Black grout is grey, not black.... Duane903 Tile Forum/Advice Board 24 04-28-2008 08:53 PM
Black Slate and Black Grout question Chloe B Cleaning, Restoration and Sealing 3 02-25-2006 07:18 AM
Grout Question-unglazed white 1" hexagon tile w/black grout jburrows500 Tile Forum/Advice Board 6 12-05-2005 09:32 PM


All times are GMT -6. The time now is 03:20 AM.


Sponsors

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2014 John Bridge & Associates, LLC