Tiling concrete floor and UF heating

[Steve01]

Hi all

I am new to the forums and looking to get my kitchen diner floor tiled which is approx 30sqm

The tiler is proposing following
1. Self level floor as old tiles were taken up and some of the adhesive is still present and not flat floor - Is this needed or can insulation boards just be applied with adhesive which will cover imperfections
2. Apply XPS insulation boards with keraquick adhesive - does he need to prime the concrete subfloor first after self levelling before putting down insulation boards if so which primer ?
3. Lay electric underfloor heating mat on insulation board - again do you just apply the primer that comes with the mat to the insulation boards and electric mat before tiling
4. Use keraquick to fix tiles to mat and insulation board - at this stage is self levelling latex recommended on top of the mat before laying down the tiles ?
5. Grout and polish tiles

Any other advice appreciated to ensure he is doing the right thing - large area and big investment so want to ensure it is right

Thanks

 

[hmtiling]

Prime, slc, prime, thermal boards, prime, ufh, slc, prime and tile. Use a primer same brand as adhesive

 

[Steve01]

Thanks

I am using keraquick do assume I need mapei primer g

Also do I need to self level after putting down ufh as dont have much height to work with or can good layer of adhesive covering cables work ?

 

[Flintstone]

Steve, why are you questioning his methods? Do you have confidence in him and have you checked out his credentials ?

 

[Steve01]

Yes he is qualified but never used him before - just when I am spending £5000 I want to ensure job done properly so like to do my research

 

[Ajax123]

Is this another "wow that's more expensive than I thought" posts. If the tiler has recommended that works be done they probably need doing and in turn paying for. You should be pleased his methods are robust. I would be more concerned if he were asking some of the questions you have asked. Let's say for instance someone here says the floor does not need priming. You tell the tiler, the tiler either walks away or doesn't prime. That becomes your spec and morally your responsibility of it goes wrong. If you don't trust his recommendations don't use him. If you do trust his recommendations don't question them.... grrr! I must be in a bad mood... grrr!

 

[Dumbo]

@Localtiler @Ajax123 i thought that as soon as i read it yesterday .

 

[Flintstone]

I'm a bit confused here steve, your first post is about a tiler and your second is about yourself doing the job...

 

[GoneGuy]

I'm a bit confused here steve, your first post is about a tiler and your second is about yourself doing the job...

Same here?

 

[Steve01]

Hi Thanks for the replies

Firstly I am definitely not doing this myself its too big a project - I have done a smaller area myself before though and did all the research hence wanting to ensure the tiler takes the right approach

When I say 'I' it refers to getting the work done on my property

@Ajax123 the cost does not worry me - I am the one that has insisted we do everything- insulation boards prime at every stage slc etc and so money is not an issue but want the job done properly

I asked 4 quotes from checkatrade which were similar and went with the one that seemed like he would take his time and do a good job

it was interesting to see what different tilers said and hence the confusion also not many tilers were comfortable with the UF heating or had a consistent view on what needed doing

some said SL on top of old tiles. some said no insulation boards needed and some said that don't need to self level on top of the UF heating hence the initial post to all you experienced tilers out there for some help - sorry but I thought that what this forum was for - for tilers but also homeowners like me to ensure we get the right people for the job and some independent QA on what they are doing

Anyway really appreciate the advice and as @hmtiling says the right approach is as he has outlined from what research has told me

so the work has started and the following has been done by the tiler:
1. old tiles taken up - approx 30sqm this left lots of lit bits of glue and tile so it wasn't a perfect surface
2. the floor was primed
3. the tiler was happy to put the 6mm XPS board down on there using the adhesive to level as he went rather than slc first
4. once the board was down he primed on top again using the UF thermal primer - I noticed some of the insulation board not completely stuck down in the evening and so asked him to go over where it was not done properly - yes that did ring alarm bells
5. after that he self levelled using mapei ultra plan - he ran out of that and used another universal SLC (which says it is suitable for UFH according to the package which I ensure I checked ) to top up the non UFH mat areas and some of that was probably used on the mat to finish off as far as I can see
6. THE SLC has been drying for 3 days and still not 100% dry but hard in most places and still drying - I am told that due to the large area and cold weather this could take a bit longer

As it dries I have been checking over the area with the SLC and some areas seem hollow although not cracking - when I knock with my hand then some areas are solid and some are hollow like there are air pockets under the insulation board where it has not perhaps stuck to the concrete or there was not enough adhesive

is this something to worry about - i.e tiling on top of the hollow areas OR will I need to get those areas smashed up and corrected - no doubt the mat would be damaged and would require almost restarting ?

I did my research and hired someone who seemed to have the right credentials but am now a bit worried - I do pay attention to detail and have been checking work at every stage - its who I am - if I wasn't on site or left him to it I am sure all the tiles would be down now and I wouldn't know any different until perhaps I had issues in future

I am sure I will get lots of advice on the type of tradesmen I should or shouldnt have got but would really appreciate some advice on what to do next primarily the concern is around the hollow sounds on the floor - it is hard and solid to walk on but as I said just hollow in some areas which I don't want to cause issues in future

I will be getting 600 x 600 porcelain tiles fitted

Many thanks in advance for your any advice

 

[Boggs]

6. THE SLC has been drying for 3 days and still not 100% dry but hard in most places and still drying - I am told that due to the large area and cold weather this could take a bit longer

3 days?!

How thick was it?
Is it open to the elements?

I would think it should dry overnight.

 

[The Tiler]

was the underside of the XPS boards primed?
used to have to prime all faces of the blue XPS boards and let it dry before fixing

 

[Steve01]

hi yes it was open to the elements for 2 nights as there was a door partly boarded and letting cold air in - also it was 10mm thick as it was quite an uneven floor

 

[Simon Dale]

hi yes it was open to the elements for 2 nights as there was a door partly boarded and letting cold air in - also it was 10mm thick as it was quite an uneven floor

You can put 50mm down in one hit and it will dry by next day or even the same most SLC is rapid. Think to much water used.

 

[Boggs]

The last slc I used was fast track and we were walking in it within the hour.