Why do you need to tank/waterproof - Tile Advice

[Jamorgan90]

Hi all,

Just a quick question. Why do you need to tank/waterproof a bathroom behind tiles when tiles,adhesive and grout are all water proof? If water gets behind the adhesive surly it will break it down over time anyway?

 

[CJ]

The old assumption that the cement & grout is "Waterproof" when it's not.....its water resistant.

Tanking waterproofs the substrate.........and then water cannot damage that substrate. If the tiling and grouting is done properly, that substrate should not get damaged.

 

[Matt Bott]

ive been to a few jobs that because no tanking the boards have absorbed moisture then expanded and forced tiles of the wall

 

[Qwerty]

Hi all,

Just a quick question. Why do you need to tank/waterproof a bathroom behind tiles when tiles,adhesive and grout are all water proof? If water gets behind the adhesive surly it will break it down over time anyway?

Water will not break down cement based tile adhesive, ready mixer dispersion adhesive yes but not bagged addy. I give it another 5-10 years before its standard practice here as it is in some other countries. I have seen far too many failed shower areas to not tank. I can't remember the last shower I tiled without tanking first.

 

[Jamorgan90]

Yes but surly water shouldn't be getting behind the tile in the first place?

 

[Flintstone]

Doesn't take much of a gap for water to get though and when most showers are used a few times per day, that's a lot of water. It will penetrate through grout as well.

 

[Flintstone]

When you have seen as many rotten soaked walls as most of us have, you will be advising tanking to everyone

 

[Qwerty]

Yes but surly water shouldn't be getting behind the tile in the first place?

You just said it....... 'shouldn't' . There always is that chance of it happening and I've seen it plenty of times on countless jobs I've ripped out.

 

[silver]

Hand on heart I have tanked every bathroom shower / bath area ....since day one.
Over the years I have "lost" work to the others that talk customers out of it / say I am stacking the price.
The added price doesn't suite everyone ....those who don't understand or accept the reasons why.
But when you are looking at an "untanked" situation that needs to come out when you quote ..and its knackered ...and less than 2 years since installation...the 10 year product guarantee against the same happening again seems a small cost all of a sudden.