Myths and Misunderstandings: Testing the water resistance of grout

[Dan]

No legs are fine. I only ever messed a hook turn up once, I hit the ground horizontal (that's how bad I got that wrong) and bounced - only injury was that I bit right through my lower lip so really, really lucky.

Don't know if you ever tried this but if you grab a mates leg grips when they deploy you can get an amazing flip off it. One day we decided it would be a good idea to do this but with a 3rd person hanging on to my legs.The thought was the 3rd guy at the end would get an even more impressive result. That's not what happens though. My top half got wrenched upwards but my lower half stayed where it was and I felt a pop in my abdomen followed by such a bad pain I couldn't even arch. I had to deploy on my back and soon after landing noticed that my ball sac was the size of a grapefruit 😱
So it's a hernia repair I'm having done next week. Almost 20 years to the day when it happened. It already got fixed at the time but now it's back (I blame all the tiling I've been doing)

Sounds painful!

 

[macten]

So what have we learnt from this? That in a normal environment if a shower gets used a couple of times a day, after a couple of days water will actually get through...?

And if it's a more course grout with any amount more than one grout joint, a lot is going to get through?

I agree if we were talking about standing water on a wetroom floor. I'm thinking more of a situation involving the walls of a shower cubicle or the shower end walls above a bath.
I've not long had a shower and 30 mins later all the jasmine coloured grout is no longer dark. I appreciate in winter that would take longer to dry out. That's a far cry from my walls being submerged underwater for 6 or 7 hours. Dean's test suggests, to me anyway, that in a normal shower environment with a shower being used 2 or 3 times a day - there's very little risk of water ingress. I'm betting the same test using a primer and a modified grout would last a lot longer.

I also think if Dean had used mosaics then the time to failure would have been the same. Yes more water would get through which would mean more real world damage in a faster time but can't think why it would initially soak through to the cardboard any quicker.

I AM a fan of tanking. It is imperative in some situations and in all the others - well if you can eliminate a risk, no matter how small, then it's worth doing in my opinion.
Just can't accept that a proper install is doomed due to the absence of tanking. I know for a fact this isn't the case because I've ripped loads out and they were fine.

 

[Dan]

I'm taking from it the fact that grout isn't waterpoof. Which was the point I was making in the thread deano linked to. Not sure a 5 day course or a 6 hour fish tank would prove otherwise.

 

[The D]

So what have we learnt from this? That in a normal environment if a shower gets used a couple of times a day, after a couple of days water will actually get through...?

And if it's a more course grout with any amount more than one grout joint, a lot is going to get through?

what i have learned from this is that it takes 6.5 hours for water to fully penetrate standard unmodified wall grout when it is fully submerged (the grout used is not anything special it is actually the bottom of the range of grouts as for corser grout you only use in kitchens and non wet areas why would you need to test them for water ingress unless you intend to use them incorrectly?)


from my test i can say with confidence i can run my shower at home for a good four hours

and that is ample time for all of the people in my house to have a shower without water ever getting as far as the background. The shower will then be off for a good eight hours which is ample time for the water in the grout to dissipate before the shower is used again.

I have a tanking system in place as a backup to protect my background should the shower ever get used for longer than the grout will withstand the water.


i say what i have learned when actually what i mean is what i have proven with my test, as i have been saying this all along. (apart from the 6.5 hours) Dan if you wish to prove me wrong you will need to do your own test but i think that will not happen as the thing i have learned from these last two threads is that you actually know far less about tiling than i previously gave you credit for.

 

[The D]

I'm taking from it the fact that grout isn't waterpoof. Which was the point I was making in the thread deano linked to. Not sure a 5 day course or a 6 hour fish tank would prove otherwise.

who ever said grout was waterpoof.

 

[White Room]

I got that right 1-12 hours🙂

 

[Dan]

who ever said grout was waterpoof.

Nobody Deano. Nobody mate.

 

[widler]

I thought it would be quicker, i didnt vote though, i forgot 🙁
I think it proves that tanking a wall is not esential , to be honest and i hope the rest of the folk on here don't bull#### , tanking domestic showers did not occur until recently(im sure 1or2 will have 🙂 ) , ive never seen it being done in the 80/90/2000s , possibly only the last few years since wetrooms became the rage .
Yes ive seen failures , but its usually a really crap job to begin with .
Cheers dean for taking the time to do it

 

[Dan]

WP1 by BAL was about in 2002 for sure. Sold it at topps back then. Whether I was used or not is another thing.

 

[Old Mod]

I thought it would be quicker, i didnt vote though, i forgot 🙁
I think it proves that tanking a wall is not esential , to be honest and i hope the rest of the folk on here don't bull#### , tanking domestic showers did not occur until recently(im sure 1or2 will have 🙂 ) , ive never seen it being done in the 80/90/2000s , possibly only the last few years since wetrooms became the rage .
Yes ive seen failures , but its usually a really crap job to begin with .
Cheers dean for taking the time to do it

Well Craig to be honest mate I've been tanking showers since 2006, not every one I'll grant you, but that's when it was first spec'd for me!
So certainly with some of the architects I've encountered tanking has been something they've believed in.
Just because something is 'new' doesn't mean it's not a good idea.
If the client asks for it, I'm certainly not gonna say "nah s'alright missus u don't need it!"
And I will always suggest it because I do think it's a good idea!
It certainly can't hurt, and it can only increase the longevity of a finished project, so why shouldn't I encourage it?
And I'm certainly not saying this experiment has had no merit, because it has, it's proved very interesting actually!
But u seem dead set against tanking Craig, is there a reason mate?