wetroom falls forming

[ds1980]

Have had some great help especially from wetdecs but saw a wetroom today that simply slopes down t then levels out with just a circular drain at the bottom.

I was 90% sure i was going to get the tilux former but realise now that it is 40mm deep and i might not have that amount to play with so just looking at other options this seems to work and doesnt involve the complicated slope forming of that the formers provide. Just a fairly simple slope from what will be our shower door to the wall where the shower will project out from.

We're downstairs on concrete floor. If it is possible is that type drain ok as the formers or rooms that look like that have the linear drain? will i just need a primer or would tanking now be needed. We will be using the aquapanel type boards in the wet tiled area.

have attached a rough diagram of what i mean sorry!!

 

[paul flight]

have a look at trays on tilefix direct . i use them . easy to install only 20mm thick

 

[ds1980]

don't want to use the "flimsy ones" if possible? sorry should have said. Assume those are the ones you're referring to

 

[The Legend; Phil Hobson RIP]

Have you thought about forming the fall with a sand and cement screed? I might have missed something, And then tanking. Our colonial cousins still do it this way US tilers. See Rob Z in members list

 

[ds1980]

yes that's what i'm talking about!!! will look him up ta

 

[The Legend; Phil Hobson RIP]

yes that's what i'm talking about!!! will look him up ta

If you can't get hold of Rob, PM me I will talk you through it,

 

[Rob Z]

Hi DS, I got your PM....

We do this kind of thing a lot, and when going over a concrete slab we install a bonded mortar bed and shape it with the required fall to the drian. My buddy Phil is bilingual because he's done a lot of work in the US, so he'll have to helps with the translations on the terminology.

Depending on the thickness of the bed at the drain, we use either regular drypack with concrete sand, or it if has to taper out to a thin area around a drain (less than ~1/2" or so), we downsize the sand to mason's sand. We bond the mudbed to the slab with a wet mix of thinset with latex additive. We sometimes use a latex additive in the mud, and with your situation I definately would because the mud is going to get pretty thin around the drain.

This is the additive we use: Laticrete 3701. This will make even a very thin layer of mud extremely strong and will perform where other mixes will fail. The 3701 makes this mud very stickly and harder to work than regular mud that is mixed with water only.

For tapering around the drain to a thin point, we will goose the mix with portland and go richer than the typical 4/1 mix, and might go down to 3/1 or even a shade richer than that. Normally we might worry about cracking because that's such a hot mix, but with the full latex treatment and the thin cross section it works just fine. We mist it with water once we're finished floating the mudbed and then cover it and leave it for a day or two. This mix will cure out and be extremely strong and work well.

If you can't get Laticrete there I'm sure Mapei makes something that is the equal to the Lat 3701.

http://www.laticrete.com/Portals/0/datasheets/lds2310.pdf

I hope this is what you were asking about and I didn't misunderstand your question. If you have any more questions please ask.

 

[ds1980]

excellent thanks rob,

couple of things. Is a circular drain ok at the end? If so can someone point to to a good cheap one?

Have attached a pic again sorry to what basically we want to do. See the tiles slope down to drain.

Tiles we are using are travertine 20x20 so was hoping to leave 200 mm at the end that flattens out?

We don't have to necessarily go down to 0mm. I think we have 40 mm max to play with but we shall see.

THe outside area of the pic is raised about 10-20mm so there is a lip should i do this or can i have level flooring throughout. We will have a door mind rather than a fixed panel so there will be a gap underneath i suppose?

Finally do i need to waterproof this now also? we are using the tile backer boards on the wall. we are also doing under floor heating would i still put down the backer board on the concrete slope? sorry for all the questions

thanks,

ps is isolastic the mapei product?

 

[Rob Z]

Hi DS,

Mapelastic is the waterproofing product that I know.I haven't heard of "isolastic", although it's possible that it has another name outside of the north american market?

broken link removed

The dimensions you are listing can work I think. I'm converting to inches and it seems doable. We try for a slope of 1/4" per foot, which I convert to ~6 mm per 30 cm. How does this compare to the standards for shower floor slope in the UK? Sometimes, I'll cheat that slope down flatter if need be and if the tiles are smooth enough such that I know I'll get good drainage. This might need to be done to get the elevations to work out for your installation. The flat area of ~200 mm (4") should work. I would try to cant that last row just slightly from the wall. We use square drains rather than round ones. It seems to work better when getting the cuts and the tiles oriented around the drain when trying to do one of these floors.

You asked about backer board on the floor? I would shape this floor with drypack. And waterproofing? Yes, all of it, and tie it into the drain. One thing I don't know anything about is the drains that you have available there. We have drains here that can be used so that waterproofing can be tied into them and the entire floor can be waterproofed. How is it done there with the type of drain I see in the photo?

I don't know what to say about heat in the floor of the shower. I don't know if that is allowed here where I live, and I've never tried it or even seen it.

 

[ds1980]

Seems this is the stuff

broken link removed

Backer board is for the UFH as it takes longer to heat on just concrete.

Think the drains come with the flange membrane hopefully so that should be fine.

Great though thanks im sure ill be back at some point.

ta

 

[wetdec]

don't want to use the "flimsy ones" if possible? sorry should have said. Assume those are the ones you're referring to

At last someone without industry connection has made a perfectly honest comment...........................


,,

 

[ds1980]

Just spoke to mapei technical and their advice is not to bother with the latex??? isolastic is not the alternative either.

 

[Rob Z]

DS, Mapei said not to use latex in the drypack? I'm not very familiar with Mapei's product line, so I don't know if they have latex made for drypack. You could check and see if Mapei has a product equal to Laticrete 3701. I'd be interested to hear why they recommend against using latex in the mud in this kind of application.

Have you worked out a solution for your installation?

 

[ds1980]

perhaps i didnt explain it too well but ill wait and see what the old man has to say he's been doing this 50 years but he is very old school! Thinking i will perhaps just add some tile primer? Ill let you know. not sure when he can fit me in he's booked up for about 4 years!! Hopefully he can squeeze son in law in soon though.

Mapei Tile Adhesive Primer 1kg - NoLinksToThis, Where the Trade Buys

As for underfloor heating not going to take into wet room part just outside. so i can just use correct height backer boards there and apply the wire as necessary where i need it without complicating things.

One thing i'm still contemplating is tanking though. As im using aquapanel on the walls and a concrete base do i really need to??????? We are downstairs and as such don't envisage any problems. Believe me the works will be done very thoroughly! I do think for an extra days "hassle" i should, but not convinced i need to? Think i just need to use a certain tile adhesive and grout?????

Thanks for all the input so far guys....

 

[ds1980]

ok wetroom started yesterday. ceiling going in then onto drains and the wetroom floor! Have now had the idea that we fill form the slope from the wall in which the shower goes. Ie the other way to the drawing. The drain would now be near to the front of the shower. I see this as a better solution as then there will actually be a small step now into the shower as we are having ufh outside. Will let you know how i get on but can anyone see any probs with this? Lastly is it worth tanking the bare brick aswell as when weve got the aqua panel up?? just to be on the safe side. I didnt think so as its a concrete floor downstairs room?

ta