Creating a wet room on a concrete ground floor - Tile Advice

[Grumpie]

I am converting a garage into a bedroom with ensuite facilities. There will be wc, wash basin and a wet room style shower area. I realise it is necessary to tank the walls (dry lined) but as the floor is concrete is it necessary to tank that as well.?

The whole area will be about 2.8m x 1.7m. I've read plenty about wet room floor systems and trays to acheive a fall to a drain. Is it cocher just to screed a fall onto the existing concrete floor and then tile it? I'd prefer to us a corner drains if possible to reduce the amount of excavation work for the drain - good idea or bad idea?

 

[Defy]

Re: Creating a wet room on a concrete grnd floor

The impey system is nearly as expensive as their base is and the shallow bases arnt brilliant on concrete as the vibration in the base is a pain. Have a look here just been nosing at it in the wetroom forum. This base looks good for new screeds

 

[Daz]

Re: Creating a wet room on a concrete grnd floor

I completed a wetroom for a customer last week. I, initially, laid underfloor heating and then chucked a self levelling compound down working the self leveller to create a fall to the corner drain.

I then tanked the walls with Ardex WPC and the floor with Tilesafe (tile-safe.co.uk).

Stuck large format tiles on floor and walls (would have preferred to use a smaller format for the floor but customer refused to allow me to cut tapers in the tiles etc. etc.) It actually worked out well and the water drains away without pooling so "happy days"!

 

[wetdec]

Re: Creating a wet room on a concrete grnd floor

Concrete floor in wet room does not really need tanking unless it is a new install or has in screed heating.

To create falls in wet room is quite difficult and for the cost of say a Tilux wetroom former with gulley it isn't really worth it.

You can find answers and solutions to your how to wet room questions aail myself.


tiler

 

[Alberta Stone]

Re: Creating a wet room on a concrete grnd floor

Concrete is very porous and will offer a place for mold to grow, if any water actually gets into it.
I would use redguard or mapei HPG, just to be on the safe-side.

 

[sWe]

Re: Creating a wet room on a concrete grnd floor

I'd tank the floor. As for creating a fall: it's actually not as difficult as one may think. If you intend to use a screed, it's a bit difficult, especially over a large area, but it's not so hard with self leveling compound.

You seal of the gully using foam tape strip, which you wrap around the edge of the gully, creating a barrier. Then you pour slc around the borders, begining fursthest away from the door. As the SLC floats out, you'll get a fall automatically. You can use a trowel to adjust the SLC as you go. When you've poured the entire room, you want wait until the slc doesn't stick to your finger when you touch it, before you go into the room, to the drain, and scrape away excess SLC around it and remove the foam strip. You can also adjust the fall in the rest of the room, if it's not good enough. Keep in mind that the SLC where you started dries first, so you may have to walk on the SLC close to the door before it's stopped sicking. A tip then is to put a piece of ply on the slc as a stepstone.

That's how we do it over here, and we treat every single bathroom as a wetroom.

It may sound complicated, but it's not. The first time I did it on my own, the result was quite good, and even if you screw up slightly, you can make minor adjustments with rapid set, or simply pour another coat.

I recommed Ardex K75 for pouring wetroom floors. And appropriate fall, by the way, is 1cm/m in the entire room, except in the 1m radious around the drain, where you want about 2cm/m. Also, I recommend that you don't use floor tiles larger than 20x20cm, as you'll have to cut larger tiles to avoid lippage and preserve the fall.

 

[cornish_crofter]

Re: Creating a wet room on a concrete grnd floor

Wetdecs has mentioned the Tilux former.

IMO it is GREAT!

I have fitted one recently and have tiled it without a problem.

Read about it here:

It's a bit of a toung and cheek account. It was actually very easy to do. My problem was that I tried to do too much at once.

Ideally you should get the former level, but I didn't quite manage this in one corner, so I compensated with a bit more spf in that area to make sure the sides all had the same fall.

Don't be put off by the material the former is made of. It's actually as hard as concrete when it is installed!

 

[Deleted member 1779]

Re: Creating a wet room on a concrete grnd floor

Our wetroom was downstairs and fitted into the existing concrete slab which is / was the standard wet pour concrete (uneven) over rebar mesh inished with a cement screed to make it level. The room was pretanked with a tar based with a 6 inch "lip" because the room was semi below ground level. In the photo below you can see the tanking lip as a white skirt. Once we got in there to fit the new wet room the whole floor was tanked with bal tanking to prevent and mould / damp / mildew. The room is now double tanked.

And dont anyone dare say in which order is the before and after piccie.... !!!

PS: I was worried that cold tiles on a cold concrete pour would lead to cold feet. And I was right. It does. In hindsight UFH would have been the choice. But it was five years ago when project money was tight. But the tanking of the room was still in my opinion money well spent.

 

[dumbrill]

Re: Creating a wet room on a concrete grnd floor

Also, I recommend that you don't use floor tiles larger than 20x20cm, as you'll have to cut larger tiles to avoid lippage and preserve the fall.

I've read this comment in a couple of places and I don't understand why this is the case. If tiling on on to a flat surface at a 1:100 gradient why will lippage be a risk on larger tiles? Is it because after laying the tile will try to float back to level? If so can it be corrected by using the right adhesive?

 

[doug boardley]

Re: Creating a wet room on a concrete grnd floor

I've read this comment in a couple of places and I don't understand why this is the case. If tiling on on to a flat surface at a 1:100 gradient why will lippage be a risk on larger tiles? Is it because after laying the tile will try to float back to level? If so can it be corrected by using the right adhesive?

because usually in a wetroom (unless you're having a linear drain) you've got "fall" coming from 4 directions to marry up at the gulley.
Hope this makes sense

 

[The D]

Re: Creating a wet room on a concrete grnd floor

it makes perfect sense to me.