DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Flooring (
-   -   moldy grout (

jimmy21 09-06-2008 08:51 PM

moldy grout
39 Attachment(s)
i have a customer that wants me to re-grout their tile shower because the grout is moldy, no matter how many times they clean it. Is there any chance that regrouting it will do anything? or would the problem have to be behind the tile? They said the grout hasn't been sealed in like 13 years

Bud Cline 09-06-2008 10:41 PM

Re-grouting isn't likely to change anything. Tell them to clean it properly then do whatever is necessary to rid themselves of the conditions that promote the mold growth. The mold isn't the grouts fault, it is the fault of the homeowner.:)

If the shower was cleaned regularly there wouldn't be anything for the mold to feed on.

If the shower was dried routinely there wouldn't be any moisture to support mold growth.

If the room air was exchanged on a regular basis there wouldn't be anyway to grow mold.:)

jimmy21 09-06-2008 10:45 PM

39 Attachment(s)
so you don't think it likely has damage behind the tile?????

Bud Cline 09-06-2008 10:47 PM

Don't know. Re-grouting isn't going to fix "damage behind the tile". What kind of damage could there be hehind the tile and where would this damage come from? What kind of damage?:)

Nestor_Kelebay 09-06-2008 10:53 PM


Is this mold or mildew?

Scratch that "mold" with something hard. If the grout behind the black mold is clean and white, then it's not coming through the grout so there's nothing to indicate a problem behind the tiling.

I live in the real world and know that most of my tenants don't bother to even wipe down the ceramic tiling after a shower. They don't even bother to turn on the bathroom ceiling fan.

Tell the customer that their best options are to clean the grout properly and then seal it. Take a look at my post in the thread in this forum entitled:
What works and what doesn't to clean grout?

Also, depending on the tile size, you get more bang for the buck by replacing the tiling than replacing only the grout.

Bud Cline 09-06-2008 11:01 PM


It's more work to replace the grout on a bathroom wall than it is to take the existing tiling off and install new ceramic tiling.
Are ya kiddin' me Kelebay? IT IS NOT!:eek:

jimmy21 09-07-2008 01:05 AM

39 Attachment(s)
ya, im gonna tell the homeowner what you guys told me, that it probably just needs to be cleaned thoroughly and sealed

id love to spend all day scraping grout out since we agreed on T&M but i wanna take care of my people

ccarlisle 09-07-2008 06:59 AM

To give you an idea of the scope of the problem, we normally quote $500 minimum for a job like that, with the stipulation that the final bill may end up in the $3-5K range and the only thing we can promise the homeowner is a starting time, not a finishing time - nor a cost.

Those jobs are cans of worms and a case of the appearance being only a fraction of what the job might entail. Can go from a clean and seal to complete removal of three walls and new plumbing...

What we have found that makes us quote those numbers are that mouldy grout is a symptom of a sick shower; mould is growing from the back through the grout and will continue to grow even after the cleaning. How many times have we started what seems to be an easy job and ended up with the first tile we cleaned in our hands or smashed to pieces in the tub...just fell off. What we often see is bulging walls, the bulging due to mould growth.

In many instances regrouting won't work but if the customer insists we do it, and even using a Fein grout tool, the job is lengthy and carries no warranty. If the tiles are smaller than 4"x4", then we turn it down. If that's the case, replacememt is a better option and carries with it a warranty. Most go for it. If the tiles are large, then loose tiles becomes a concern then it is better to redo the shower.

We regout in only some situations, mostly on floors coming to think of it but where there's evidence of mould on walls, we try not to. When you bring out the full arsenal-and-slideshow of making a waterproof shower in 3 days, with something like 30-40 years of no problems, then 3-5K all of a sudden becomes viable, especially in situations like this one where the grout is black. Educating the customer usually brings us work done the right way...


clasact 09-07-2008 07:24 AM

ccarlisle you say this is a symptom of a sick shower? would that be that it was not properly water sealed or poor tiling ? Please explain more I have been building my own showers in my home and would like to make sure I avoid this problem.Thanks

ccarlisle 09-07-2008 08:00 AM

'Sick' showers are a plague up here; I'd say that 80% of the existing showers are not 'waterproof' and the state of their health just a dot on a long road down to demolition. But the fact is that, as homes become tighter, we see it more and more. I don't know about places further south than us, but up here it's almost a given that showers built anywhere between 1975 and today are either sick or terminal.

Sick showers come from excess humidity and less than perfect cleaning and drying regimens. I don't expect everyone to wipe down the tiled walls and I don't expect everyone to have huge exhaust fans so in time, given the practices of shower building of old, mould will set in. Up here, they used to use drywall, now cbu, to support the tile, and mastic of course. So even with our "dry" winters indoors, the showers would never fully dry out. Plus the fact that we use lots of electric heating and comparatively little air movement...

So the problem becomes poor construction, not poor tiling. The grout isn't at fault, it may contribute, but not 'the' problem per se. Same for sealing...for at least the past 15yrs, there have been waterproofing membranes that prevent the problem from even starting, some better than others, so why not adopt them? Building codes have not kept up with the industry. And of course, people want everything "like, yesterday" - even complete shower reconstruction which is at minimum, 3 days.

Even on your West coast, there are still people who put up showers using roofing technology, complete with hot tar mopped onto the pan. Then there are the mud guys...look, I have nothing against the tar or the mud people, but it just seems to me that technology and evolution have gone beyond that. Used to be that water in a shower would go through the grout, dribble through 1-2" of packed mortar to finally trickle down to a drain that really could only be waterproofed by pure professionals. No waterproofing on the walls...but dry weather helped out alot too. The shower never had a chance to dry out. A smorgasbord for mould...:yes:

Anyway, I just see what I am surrounded with up here; and here we favour showers drying out between uses, and design systems that enable that to happen. So, yes we use waterproofing membranes, yes we use powerful exhaust fans on timers, and yes we grout, then seal a few days later. So mould has nowhere to set in. No food, little moisture, good air movement.

That's a healthy shower in my book.:wink:

clasact 09-07-2008 08:10 AM

Thanks for the reply from what you wrote I have done my homework and built my showers correctly.I used sandtopping for the base covered with the Sulster (sp) membrain,tiled and sealed ,I also put a 130cfm in the shower stall and another 70cfm out side it about 4ft away both come on durring a shower

ccarlisle 09-07-2008 11:49 AM

Sounds good to me...what do you mean by 'sandtopping for the base'? some terms I'm not familiar with. Great fans!

clasact 09-07-2008 12:21 PM

sand topping cement mix

jimmy21 09-07-2008 12:23 PM

39 Attachment(s)
since we are on the topic of tiled showers and im planning on building one in my own home, are there any membranes cheaper than kerdi?

and ccarlisle, i was pretty much on the same page with you when i talked to them. I told them i doubt redoing the grout is gonna do anything and i think the problem is either behind the shower or on top of the shower, but redoing the grout isn't the solution. I think im gonna clean the crap out of it, and then seal it up real good, and having them know it might not work

clasact 09-07-2008 12:29 PM

to be honest Jimmy the kerdi was much cheeper then the rubberized stuff both the box stores were selling as membrains.I also dont think this is the area to skimp on since it is really the protection for the whole thing

All times are GMT -5. The time now is 04:18 AM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1