Myths and Misunderstandings: Testing the water resistance of grout

[WetSaw]

It's fun in The Arms isn't it!

 

[Dan]

Yeah don't mention dot and dab in here. Christ, heavens open and all sorts.

 

[WetSaw]

Dot 'n Dab are my best mates

 

[Spare Tool]

Great this pub...speaking of dot n dab followed a van the other day
Might be doing the guy an injustice but 'jack of all' fffssaake 🙂 look closely and tilings on there

 

[Rizzle from the Portizzle]

ok time to bring this to the real world uk over 100 million bath and shower rooms 99% grouted with love water grouts refurb rate evey 7 to 9 years main reason for refurb out dated .one day fat will kill you next its good for you .to many vested intrest to many without the courage to question .so the king is in the all tougher all tougher as naked as the day he was born .respect those who question for you. while all you know you are told the three wise monkeys of tiling.dean you did not know the answers but were willing to look for them if only 1 in 1000 tiler did the same we would be telling them not them telling us

 

[widler]

I beleive in aliens

 

[SJPurdy]

Is tanking BS in domestic showers?
I mean in wetrooms , its obvious , but in a domestic shower ?

BS are recommendations only ( but could be used as evidence - so if not followed and something goes wrong!). As I said before I think a professional tiler should inform a customer of the BS recommendations so that it is the customers informed choice as to wether to pay for it - although ideally in the future it should become a "building regulation equivalent" so that anyone buying the property in the future will know the standard that it has been constructed to.
Application of tanking is recommended for all showers where the substrate would potentially be damaged by the ingress of water through the tiling layer. The tanking is to protect the substrate.
This is from memory as I no longer have a home copy of BS to refer to.
You do not therefore have to apply tanking over the top of eg. a waterproof tile-backer board (assuming joints are all appropriately sealed - and I would even recommend a secondary elastic tanking tape seal over corners in wet rooms as these are the obvious weak points).

Personally for new build showers I think tile backer boards should be used as tanking the tiled surface of eg plasterboard is often pointless as the leaks are often from the plumbing joints which are on the un-tanked side of the board.

I wonder how many different manufacturer's tubed D1 adhesive instructions still state that they can be used in domestic showers?

 

[The D]

This will be my last post just to clarify my point.

to start with i am not and never have said that tanking is a waste of time. i do however think that tanking is a very important back up to tiling, should the tiling fail the tanking is there to protect the back ground.


On the subject of grout we all know that grout is not water “proof” but that does not automatically mean it will not offer any resistance to the water. my test in this thread showed that a bog standard grout will resist FULL submersion in water for over 6 hours.

I have no doubt that in a domestic shower as long as the grout has no defects it will resist indefinitely.


There has been a misunderstanding somewhere along the line and pics posted of failed tiling and damage to backgrounds but none of that is due to water ingress through a well grouted joint. This sort of damage is more often caused by bad workmanship. I am certain that if you call any grout manufacturer and ask how many failed domestic installations had been caused purely by water ingress through a well grouted joint they would tell you none.


As for water passing through the grout and sitting behind the tiles and the tiling just being decorative this is just stupid if that was true why would we bother having tiles. I asked a BAL rep about it as this is the first time in 30 years of tiling i have come across someone with this misconception and i was told in no uncertain terms that this was not the norm and if there was water behind the tiles this would be a H&S issue. it had nothing to do with the tanking being a H&S issue that is just another example of someone being given information and totally misunderstanding it.

 

[widler]

It's what I've been trying to get across deano, bad workmanship will cause failure, it just doesn't seem to sink in some folks heeds
They can or can't in this case ,qoute BS about it defo without question being needed in every domestic shower in the whole wide world cos it will fail without doubt and we will be smited down by the hand of God and cast into hell
Personally , in some cases hell looks the better option

 

[WetSaw]

I've only recently been seeing these new fangled tanking kits in the plumbers merchants over here.