Another newbie building a wetroom

[igro49]

Hi Everyone

It would be great if you guys could comment on how I am going to build my wetroom.

It is on the first floor of a new extension, no floorboards, just 2x8 joists now; two stud partition walls, one wall of aerated concrete blocks (new build) and one solid brick wall that used to be the external wall of the house.

My list of jobs:

1. Noggins.
2. Tuff2 former tray 1400x900. (Chosen after detailed advice on this forum; many thanks for your explanation, Wetdec.)
3. 22mm marine plywood for the rest of the floor.
4. Plasterboard for walls, nailed to stud partitions, adhesive to concrete/brick walls.
5. Dura-CI membrane on the floor using flex adhesive.
6. Dura-WP membrane on the walls using flex adhesive.
7. UFH on the floor, loose-wire because of the funny shape of the room.
8. Flex screed on the top of UFH.
9. Porcelain tiles on the floor, ceramic tiles on the walls, using flex adhesive.

Now, my questions:

First, of course, what did I miss in my list? Is it correct? Are there any better options?

Which membrane is it better to use over the tray itself, Dura-CI or Dura-WP? If it is Dura-WP, is it enough to use 18mm plywood for the rest of the floor?

What else can I do from the point of belt-and-braces approach, mostly regarding waterproofing? I am making the wetroom for myself, and I am happy to go with some extras even if it is overkill, provided the extras make sense. For example, I have read somewhere about a layer of liquid tanking on the top of the membrane – does it make any sense? If I use tile backerboards on the plywood and/or walls in addition to the membrane, probably it will make no harm. (Apart from some pounds from my wallet of course!) Or is it just crazy?

Finally, I would appreciate any advice on minor details of the job (like sanding the tray surface for better adhesion, of which I read on this forum). I am going to do most of the job myself, with casual involvement of a plumber friend.

Thanks all in advance for your patience.

Igro

 

[brian c]

you seem to be on the ball.Flexible grout i would use.also SCREW plywood to noggings dont nail them,put extra noggings in to reduce bounce on floor.Might be a better idea using hardie backer rather than plasterboard around shower area.

 

[DHTiling]

Some things missing..

Primer..

Corner tape..for all internal corners. before main tanking.

Deffo sand the tray to obtain a good key and i use the wp on the trays..

Here is a video on the tanking walls etc..

[ame=http://www.youtube.com/watch?v=pigKorqimGk]YouTube - Durabase wp wet room tanking membrane dura-wp[/ame]

 

[igro49]

Hi

Great advice!

> Flexible grout i would use.

Yes, sure, both flexible adhesive and grout.

> also SCREW plywood to noggings

did I say nail?

> a better idea using hardie backer rather than plasterboard around shower area

12mm presumably. Does it make sense to also use it on the top of plywood, or is it complete overkill?

> Primer..

Sure, thank you for reminding.

> Corner tape..for all internal corners

Definitely, it is just a part of tanking.

> Deffo sand the tray to obtain a good key

Any other tips?

Thanks a lot guys.

Igro

 

[ryan_0405]

Hi Igro,

It looks like you've got the list covered, only thing i would change is the 22mm Marine Ply for 25mm WBP Ply as your tanking the floor. Marine Ply costs a fortune where as 25mm Exterior ply will be about £40 - £55 a sheet

 

[dock]

it would be a good idea to put the ufh under the tanking membrane as some don't like getting wet

 

[Gazebo]

never put ufh under membrane.?

is that ok to do with impey tilesafe.?

 

[wetdec]

never put ufh under membrane.?

is that ok to do with impey tilesafe.?

100w/m2 max over tilesafe................



.

 

[Gazebo]

but can u put 100w under tilesafe.??

 

[wetdec]

but can u put 100w under tilesafe.??

I would get impey themselves to email you the answer to that tilesafe is a little temprimental..............

..

 

[Diamond Pool Finishers]

just a question wetdec , lets say over the years water migrates through the grout of the floor of the wet rooms it cant go through the membrane of the tanking, so what happens to that water ,+ the continual wetting over and over,does it stagnate and start to smell???or blow the tiles off or what!!??

 

[wetdec]

Well in theory tiled walls work like walls in old houses they made them 18/24 inch thick they got wet in winter but never so wet it penitrated to the inside then in spring summer they dried out again. Because they were not totally submersed they didnt get soddern.

Grout in domestic situations works in the same way if there is any - and there will be moisture ingress it dries out in the dry period.

The tanking is there to prevent water damage from the installation, eg into the walls or through into downstairs. This can happen when there is a surface or joint failure allowing water to get in which as we all know happens over time.

Water from this type of water ingress would stay there but be prevented from damaging other areas by the membrane. In the case of our membranes smell doesnt become an issue really as there are few or no proteins between the tile and the membrane.

As for blowing the tiles cement based adhesives are pretty much bomb proof these days when it comes to water and with most cases of blowing with powdered adhesives its the substrate which fails.


..

 

[diamondtiling]

When we fit out a shower room in say a leisure center the tanking is applied to the walls as normal, it carries on across the floor following the falls to the stainless steel pot that we have already fitted. The tanking then carries on into the pot which is connected to the waste water pipe. When the tray gulley is fitted to the pot it just slides in leaving a small 2 mm gap around it, it sits on lugs inside the pot to keep it level as it has falls built into it. This gulley is then supported by a screed and then the floor is installed with falls to suit. The 2mm gap is there to catch any water which may penetrate the tiles over the years, I have often wondered why this system is not incorporated into a preformed tray as it is there to stop water from just sitting beneath the floor tiles.

:20:

 

[Diamond Pool Finishers]

if water stays there then, and tile adhesive being only water resistant,in effect sponges the water up, then all this is behind the the tiles,it cant be good,! so would it not be better to have a fully waterproof covering in the first place instead of tiles + tanking like plastic??? and thats without UFH complicating it further

 

[wetdec]

Sorry Gooner


Sorry was thinking walls - on floors as mentioned by diamond tiling the membranes we use clamp into or are factory fixed into the gulley. Any standing water that could drain would run towards the gulley and be taken away.


..

 

[wetdec]

would it not be better to have a fully waterproof covering in the first place instead of tiles + tanking like plastic??? and thats without UFH complicating it further

Well now that is a question and for 20 years there have been companies in the market place trying to sell Upvc, waterproof laminates and waterproof spray coates. All of these work in their own ways - Now all you need to do now is convince the purchaser that its what they need. (that is the surface will match their suite, not be held together with silicone, work discreatley and not look like a public toilet)

 

[White Room]

Do know that there is alot of vinyl laid onto a tray and welded joints

 

[wetdec]

Well ye but this arises from safety / hygene rather than looks and is a less able / public area instalation practice


..