# Grout-less tiling with Kerdi?



## bob_cntrctr (Jan 30, 2008)

Gentlemen,

Been a while. On a recent job I came across a shower where about two inches of caulking in an inside corner had not sealed well. But, owner shows me pictures of the build - the substrate is Hardi board with Kerdi overtop. Nice work. So that got me thinking - Kerdi over Hardi - this sucker is a bathtub - watertight and impervious. So, isn't it true that, in fact, the grout and caulking are, in functional terms, completely superfluous? Really, they're just for show, 'cause the substrate can get wet all days and just keep smiling. I mean, literally, you could just tile and forget grout and caulking...which creates thoughts of some very interesting tiling ideas.....


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## angus242 (Oct 20, 2007)

Yes but that tile would eventually become a maintenace nightmare. Can you imagine the crap that would get into the grout(less) joints (dirty soap, body oils, etc) that would be difficult to impossible to clean? :shutup:


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## Donewright (Dec 25, 2010)

angus242 said:


> Yes but that tile would eventually become a maintenace nightmare. Can you imagine the crap that would get into the grout(less) joints (dirty soap, body oils, etc) that would be difficult to impossible to clean? :shutup:


Not to mention the mold that would end up under and behind the tiles.


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## PrecisionFloors (Jan 24, 2006)

angus242 said:


> Yes but that tile would eventually become a maintenace nightmare. Can you imagine the crap that would get into the grout(less) joints (dirty soap, body oils, etc) that would be difficult to impossible to clean? :shutup:


:no:

Thanks for _that_ mental image.


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## angus242 (Oct 20, 2007)

PrecisionFloors said:


> :no:
> 
> Thanks for _that_ mental image.


Did I mention all the curlies that could get stuck back there too? :laughing: :blink:


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## Donewright (Dec 25, 2010)

angus242 said:


> Did I mention all the curlies that could get stuck back there too? :laughing: :blink:


TMI brotha. TMI. Lol


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## Bonzai (Dec 23, 2009)

angus242 said:


> Did I mention all the curlies that could get stuck back there too? :laughing: :blink:


Eek


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## tazmanian (Jul 22, 2010)

you can do butt joints of smooth edge tile and no grout. just seal the joints for measure and it will look beautiful... good for marble...and other natural stones that are smooth edged


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## ChrWright (Jul 17, 2007)

As the rest have said--in concept you're correct. We don't rely on grout and caulk by themselves to hold back the water but they do serve more than just an aesthetic purpose.

You have no idea the nasties that can hide in even a well built shower. 

http://aem.asm.org/cgi/content/full/70/7/4187



> Households provide environments that encourage the formation of microbial communities, often as biofilms. Such biofilms constitute potential reservoirs for pathogens, particularly for immune-compromised individuals. One household environment that potentially accumulates microbial biofilms is that provided by vinyl shower curtains. Over time, vinyl shower curtains accumulate films, commonly referred to as "soap scum," which microscopy reveals are constituted of lush microbial biofilms.


http://www.mobio.com/blog/2009/09/26/it’s-raining-bacteria…-from-the-showerhead/



> *Opportunistic pathogens enriched in showerhead biofilms*... the showerhead is a wonderfully warm, moist, and dark niche perfect for growth of microbial communities.
> 
> Why is this a problem?
> 
> Besides the fact that it’s raining bacteria on our heads, the authors explain that increasing incidence of pulmonary infections by nontuberculosis mycobacteria (NTM) and other opportunistic pathogens has been linked to the use of showers instead of baths. Identification of the microbial communities living in the showerhead as biofilms as well as the water moving through the shower (and causing aerosolization of the bacteria present) is an area that needs further review.


I've seen a few mosaic accent bands that are mounted without any allowance for grout. Despite the fact that we know any water beating the grout won't penetrate past the substrate to do damage, I've still not allowed those materials to be installed in wet locations on our projects.

Without grout, those biofilms will penetrate past the surface of the tile where it is difficult/impossible to sanitize and clean. 

(and thanks Angus... "curlies"... I just threw up in my mouth. :sad: :laughing


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## GO Remodeling (Apr 5, 2005)

Taz, are grouting with caulk? Or do I misunderstand the butt the marble and seal for measure comment?


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## tazmanian (Jul 22, 2010)

if the tiles are smooth edged butt them and seal. have done it and seen it done many times....although i am sure i will get flack for it.
if the base is good you should have no problems with any stickies or curlies...................


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## tazmanian (Jul 22, 2010)

might i add unsanded grout can be used to go over the tiles to make sure there are no larger gaps.........................................but everyone will do it there own way


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## bob_cntrctr (Jan 30, 2008)

OK - so - yes, purely in terms of water-tightness, it's do-able. So, now, design ideas.

For example - something instead of grout - random ideas - wax, for example. Oh - candle wax! I'm just throwing out brainstorming ideas here....

ABS glue. Tree resin. Leave a few really large gaps and fill them with tree resin and stick in a spider or two. Jurassic shower.

Epoxy or other clear goop that hardens - leave a few 1-inch tiles out of the floor - fill with epoxy with a tadpole in it - ok, more PETA-friendly, it could be leaves.

Automotive paint - wait - marine paint - pour it on, sweep into the cracks - wild colours.


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## GO Remodeling (Apr 5, 2005)

dead fish, socks,garlic, cigarette butts


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## GO Remodeling (Apr 5, 2005)

seashells, starfish, coins


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## Bill_Vincent (Apr 6, 2005)

bob_cntrctr said:


> Gentlemen,
> 
> Been a while. On a recent job I came across a shower where about two inches of caulking in an inside corner had not sealed well. But, owner shows me pictures of the build - the substrate is Hardi board with Kerdi overtop. Nice work. So that got me thinking - Kerdi over Hardi - this sucker is a bathtub - watertight and impervious. So, isn't it true that, in fact, the grout and caulking are, in functional terms, completely superfluous? Really, they're just for show, 'cause the substrate can get wet all days and just keep smiling. I mean, literally, you could just tile and forget grout and caulking...which creates thoughts of some very interesting tiling ideas.....


Grout is never meant to make tile waterproof. It DOES help SHED water, and for that it would still be a big help. But without Kerdi, water can still get through a grout joint. I think everyone else has run through other reasons why this is a really BAD idea!!


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## bob_cntrctr (Jan 30, 2008)

olzo55 said:


> seashells, starfish, coins


Ya - that's the thing - very interesting possibilities when you're not overly worried about sealing.


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## bob_cntrctr (Jan 30, 2008)

Bill_Vincent said:


> Grout is never meant to make tile waterproof. It DOES help SHED water, and for that it would still be a big help. But without Kerdi, water can still get through a grout joint. I think everyone else has run through other reasons why this is a really BAD idea!!


 
Well, ya - without Kerdi, it's been an endless quest for the perfect substrate that won't disintegrate when - not if - water starts to get behind the tiles through the grout. Then there's the joints at corners etc etc. So it was important that the grout - although we know it was never going to seal perfectly forever - that it at least seal as well as possible.

But with Kerdi, who cares if the grout leaks like a seive? Whic means you can put something else in there that maybe doesn't seal so well that you would never have used before.

Like leave few tiles out and fill the hole with acrylic resin with interesting stuff in it. A seashell. Coins. OR weird stuff for the adventurous. Baseball cards. Mirrors!


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