Help preparing for Travertine Tiling

[purereason]

Hi All, I’m about to start tiling my bathroom and would really appreciate some help. I’ve spent some time looking through the site, which has been very useful, but I’d be grateful for advice on the following issues.

Using -
20cm by 20cm tumbled travertine on the floor.
10cm by 10cm tumbled travertine on the walls.
Mapei Keraflex
Mapei Ultracolour plus Jasmine

The present flooring is chipboard and I intend to use 10mm Marmox as a foundation for the UFHeating mats.

Would it be advisable to use a SLC over the UFH or could I use a weaker mix of the Mapei Keraflex to cover the mat prior to tiling?

Half the wall is currently painted plasterboard with no skim and just a layer of white undercoat, then a standard bathroom paint over the top. I’ve tested the adhesion of the paint using some tape and found it came away easily exposing the undercoat and the paper of the board in some places.

I intend to sand away the existing paint but what primer would be best in this situation?

The other half of the wall is currently tiled as we are replacing a small shower cubicle with a bath and tiling along the entire back wall. I presume the original tiling was done at the time the house was built (about 12 years ago) and I think they have tiled directly onto the plasterboard.

Would removal of these tiles be the best approach, if so, what primer would I need to use over the area afterwards?

If removing appears too difficult without damaging the plasterboard then what would my next option be?

Thanks for your help

Simon

 

[White Room]

Hi and welcome....Slc for the ufh but use some thin strips of tape to hold the cables down otherwise they may lift up when the slc is poured..

 

[purereason]

Thanks Whitebeam for the advice re: SLC. As I've never used an SLC before is there a specific type/brand that would be appropriate for this? What would be the best method to contain the SLC on the open bath side of the Marmox boards?

 

[White Room]

I just use some timber pushed against the open edge of the marmox boards to stop an overflow....slc, depends what suppliers are in your area, tile giant supply mapei, I use ultra 2 part.

 

[Mike Mike]

Simon,

This is my advice.

1. Take the old tiles off the half wall and overlay the plasterboard with some thin cement based tile backer boards on that wall, and tape the joints. Now it's water resistent (if not water proof) and stronger than the plasterboard, and you haven't got to worry about getting that flakey paint off, or whether the primer you need to put on is strong enough for the tiles etc.

2. You do realise that if you use SLC on the floor then you will need to tank it afterwards, especially if it's an anhydrite SLC? Don't just tile direct onto SLC on a bathroom floor because water will get through the grout / tiles to the SLC underneath, even if you've primed it, and that stuff falls apart when wet, so your tiles could come loose over time.

3. To stop SLC getting places you don't want it use an avstängningslist (don't know what they're called in English?? 2m x 3cm x 3cm foam with self adhesive strip on the bottom. Cut to size and stick on the floor. I always use acryl fög just to be extra safe along the edge and where it joins a wall, but they work even without)
Avstängningslist - 30x30mm, 2m, blå - BYGGmax

Best of luck!

 

[swanman]

Hi welcome to the forum

I cant really add to any thing brilliant advise from every one

Good Luck

 

[purereason]

Thanks everyone for the advice and encouragement.

Re: Tanking over SLC - what product would be appropriate for this?

Re: Walls and old tiling. Can I just clarify a few things.

I should remove the old wall tiles and as much adhesive as I can. Are there any issues if removing the tiles damages the plasterboard underneath - if these areas will be covered by the new boarding overlay?
Then board over the painted and old tile section. Would 6mm Marmox or Hardie board be the most appropriate method to cover the walls before tiling?
I then fix these boards to the existing plasterboard - can I just screw the boards to the plasterboard behind?
Then I can tile directly on to the new boards without them needing to be treated first?

Thanks again

Simon

 

[White Room]

How many m2 are there on the floor...

 

[purereason]

Hi Whitebeam, it's a small area approx 3m2.

 

[White Room]

I would use ditra on the slc, prime first, I always do and a mix single part flex adhesive to stick the ditra down with and that will waterproof the floor.

As your fixing travertine which can be quite soft and with the expansion of the ufh may crack your trav, well worth going the extra for your tiles..