To Tank or not to Tank? bathroom advice required

[TryC]

Hey All,

 

Any plumbers or bathfitters in this group?

 

I just wanted to ask if it true that when fitting a bathtub you don't need to tank it? That you only need to tank of you're going for a shower or a wet room? I spoke to a builder today and when I mentioned waterproof membranes and tanked, he said no need for tanked (it adds to the cost),and only needed if you're having a shower only or wet room. Any advice would be appreciated

[Conor]

Classi seal around the bath, tape up the corners and tanking paste in all splash zones. Realistically it's about £40 of material and an hour's work. I wouldn't not do it.

[TryC]

hmm...curious why they said it was expensive to do it then. Should I insist they Tank?

[Temp]

Never seen the floor and wall under a bath tanked. Lots of rotten chipboard flooring though.

 

The life of the seal between bath and tiles depends on how rigid the bath is. If it moves up and down even a tiny bit when you get in and out the life of the seal can be affected. I would ensure the floor is solid, perhaps by fitting 18mm WBP to the floor and make a frame from 2x2 or similar to support the lip of the bath. Get it as rigid as possible.

 

You could also use Hardibacker board or similar on the walls instead of regular plasterboard.

 

[Nickfromwales]

7 minutes ago, Temp said:

The life of the seal between bath and tiles depends on how rigid the bath is. If it moves up and down even a tiny bit when you get in and out the life of the seal can be affected.

This entire thread summarised in one sentence.

If the bath moves, it leaks. I always fit ( fitted ) battens to the rear wall, often with additional support where deemed necessary, and I've never had an issue.

 

@TryC

Check out suitable products here;

 

https://www.thewetroomstore.co.uk/wet-room-tanking-kit/

 

Cheaper than shoplifting.  

[Temp]

Many youtube vids on installing a bath don't show battens or a frame supporting the lip. This is what I would do..  

 

https://youtu.be/7Rqysh9NHts

[Jenki]

I think the word "Tanking" can be confusing. There are products that can "tank" wet rooms and are more expensive, and there is paint on waterproofing membranes that, as @Conor mentioned will cost around £40.  It makes sense to use this product around a bath especially shower over bath situations, but I wouldn't class this as tanked.

[dpmiller]

I treated our bath exactly the same as our shower trays. Batten underneath the edge of the bath, flexible upstand bonded to the edge of the bath, fleece over that and up the corner,then liquid tanking painted onto the whole wall area which was in the wet zone of the attached shower head.

[PeterW]

I replaced a bath last week where the last installer had basically used 2 brackets and 2 screws to hold the bath in place and just a bead of sealant on the edge - took minutes to remove..! Customer said it always felt unsteady when they used it !!

 

New install was batten with centre reinforcing screwed and bonded to the wall, then Fixall rapid in a full thick bead on the edge and then brackets in place too. Final seal was a sacrificial quality silicone bead.

 

If there is a shower over the bath and it’s tiles not wall panels then will use the Mapei tanking kit from floor to ceiling too.

[Nickfromwales]

14 hours ago, Jenki said:

There are products that can "tank" wet rooms and are more expensive,

Not accurate. Tanking can be done, very effectively, with the cheap liquid ( paint on ) solution, with excellent, long term reliability. Other systems like Impey utilise a very expensive self-adhesive membrane. Not necessary, just an option that is out there.

15 hours ago, Jenki said:

It makes sense to use this product around a bath especially shower over bath situations, but I wouldn't class this as tanked.

Further disagree, massively.

Tanking solution applied correctly means that you are "tanked", end of. This is dependant on it being applied according to the manufacturers instructions. I did a wetroom in a house, over timber floors, on the 2nd floor. This was for two ( careless ) teenage daughters of a wealthy couple. Clothes and water everywhere. I spoke to the client about 3 years after installing 2 full bathrooms, the aforementioned included, and he said to me, "I wish I had you do the others, Nick" as they let him down. 'Mine' are still in and being used, hassle-free, some 9 years later.

[Jenki]

15 hours ago, Nickfromwales said:

Not accurate. Tanking can be done, very effectively, with the cheap liquid ( paint on ) solution, with excellent, long term reliability. Other systems like Impey utilise a very expensive self-adhesive membrane. Not necessary, just an option that is out there.

Further disagree, massively.

Tanking solution applied correctly means that you are "tanked", end of. This is dependant on it being applied according to the manufacturers instructions. I did a wetroom in a house, over timber floors, on the 2nd floor. This was for two ( careless ) teenage daughters of a wealthy couple. Clothes and water everywhere. I spoke to the client about 3 years after installing 2 full bathrooms, the aforementioned included, and he said to me, "I wish I had you do the others, Nick" as they let him down. 'Mine' are still in and being used, hassle-free, some 9 years later.

Hi @Nickfromwales, This may be semantics but the point I was trying to make was if you apply a waterproof paint to a bath / shower then I still wouldn't class that as tanked, waterproof yes, but without the shower tray or bath the area is  not waterproof, thus in my terminology not "tanked"

 

Where as if you "Tank" a room with either a liquid and tape, or full membrane, the room/ area would be waterproof before tiling. 

The later won't be achieved for £40. (As the drain would cost more than £40.) 

I think we agree it should be done, just terminology, and there's no way you tanked a wet room cheaply (£40) I which is what the OP was questioning. 

 

 

[Nickfromwales]

£40 is the cost of a tub / kit. You buy multiples to complete the area. 

I've posted over the years in huge depth regarding this.

They don't call it "tanking solution" for nothing !!  Tanking is via a liquid or a membrane, but almost always a combined effort using both is the 'norm'.

 

4 hours ago, Jenki said:

if you apply a waterproof paint to a bath / shower

Eh?

[Jenki]

On 18/02/2023 at 20:34, Nickfromwales said:

£40 is the cost of a tub / kit. You buy multiples to complete the area. 

I've posted over the years in huge depth regarding this.

They don't call it "tanking solution" for nothing !!  Tanking is via a liquid or a membrane, but almost always a combined effort using both is the 'norm'.

 

Eh?

It's weird, but I've used liquid tanking around bath and shower for 20 years, and although it's called tanking solution, I always viewed it as waterproofing. And reserved the phrase tanking for a wet room, with shower tray former.. I've looked up the word tanking and it's clear I'm wrong in my thinking. That's how I got stuck in this wormhole.

 

So to confirm my enlightened ways.

It's very good practice, nay essential to "tank"  showers, baths and wet rooms. And it's not that expensive ☺️

[Nickfromwales]

8 minutes ago, Jenki said:

That's how I got stuck in this wormhole

Yup, lol, let me show you to the exits  

[Thorfun]

On 18/02/2023 at 00:13, Nickfromwales said:

Not accurate. Tanking can be done, very effectively, with the cheap liquid ( paint on ) solution, with excellent, long term reliability. Other systems like Impey utilise a very expensive self-adhesive membrane. Not necessary, just an option that is out there.

hi @Nickfromwales. I'm researching tanking for our shower areas at the moment. we are going with impey aqua-dec formers. I know from reading other threads that @ProDave used the same trays with the aforementioned Impey membrane kit. I'm curious as to know if you think the Impey solution is still expensive when you consider it is also a decoupling mat for the tiles when compared to a paint on solution with a separate decoupling mat?

 

Also if we're going to use the Impey UFH mat on the former (which I believe is possible) it says that their tanking solutions works perfectly well with their electric UFH and that their UFH mat is thin enough to not affect the level of the tiles to maintain a level floor throughout.

 

what say you?

[Thorfun]

further to the above I've re-read this thread and your post 

 

where you extol the virtues of the Impey system albeit a bit of a pain to install! 

[Thorfun]

actually, thinking about it some more and (completely monopolising this thread now) is it possible to do a hybrid solution with the Impey membrane on the floor and a liquid membrane on the walls? that way you get the benefits of the decoupling mat but also not the expense of using the expensive membrane on the walls.