Water UFH 800 X 800 Porcelain Tiles On Large 270sqm Room To Room Plan - Tile Advice

[bwel]

Hi,

I am in planning stage to tile must of my downstairs area. It has wet UFH and currently has Amtico laid from when the property was built 15 years ago.

I'm not sure of the stability of the screed underneath the Amtico, but I do have some areas of lifting of the Amtico, that could be heat related. The original layers of the Amtico said that the builders had some cracks in the screed, but I can see where some of the Amtico has lifted, there were no cracks, but I'm unsure if either the floor has run too hot for the Amtico Adhesive or if the High Temp Adhesive has been used everywhere.

Any recommendations on planning such a job or advise on 800x800 tile usage ?

Lastly, I want the Tiles under the skirting and door frames, how is this best achieved.

I wont be doing the works myself, but am just planning for the specification at this stage.

Thx Bob

 

[Old Mod]

Do u have any other reasons to think that the screed is unstable apart from the Amtico lifting?
Are there any areas of floor that sound different when walked on or tapped with your knuckles? (Hollows in screed)

In essence u'd be looking at removing existing floor covering, removing or at very least neutralising the old adhesive.

Assessing condition of existing screed.

Making repairs if required.

Probably levelling area to take new floor, tile formats of that size require an excellent substrate, with soft flooring this is not so important.

Installation of a decoupling matting, especially if screed condition is acceptable but not perfect.
Others will probably disagree with this, but for me, with an investment this large, the added protection from future problems far outweighs the cost.

On a floor area that size, insertion of expansion joints in strategic places if not already in place.
Preferably through screed, or at least cause weak spots to try force it to crack where u want it to. It is possible, even with UFH.

Good setting out, this will be crucial to make the most use of your material and to prevent unnecessary waste. It can mount up fast with such a large format.

Tile and grout.

As far as skirtings and door frames go, skirtings are best removed or if that's not possible they can be undercut, however this is time consuming and would incur a much higher cost than just removing them.
U'd have to do a costing exercise between undercutting up against removal, replacement and redecoration.
Bearing in mind there is likely to be some skirting damage, depending on how they're fixed etc.

Door frames, decent fitters undercut door frames and architraves as a matter of course.

Other things to consider are, protection to upper floors, (dust control walls, furniture, kitchen units if not being removed and any other existing fixed features. Bifolds, patio doors for example.
Access in and out of building, water and electricity supplies.
Large work space, preferably covered and in close proximity to work area.
Storage area for all tiles and relevant materials, there'll be quite a bit!
If u or your Tilers need to keep moving it all, it'll become very tiresome, very quickly.
Scheduling other trades in correct order, as to not cause a break in continuity.
Waste removal, not everyone will be licensed for this, and there will be a substantial amount.

Whilst the items listed directly above may seem not so important, in total it can mean the difference between a smooth running job where everyone is happy, and a project that everyone dreads turning up to.
Have fun.

 

[One Day]

Hi. Amtico up - TileMaster Prime+Grip on the adhesive residues (please check with TileMaster technical though)
Flexible smoothing compound if/as required. Ditra uncoupling membrane (deals with the possible cracks and movement). Tile with S1 adhesive. No runs longer than 8m without fixed expansion joints and probably a good idea to fit them between rooms too.

 

[Lee@emctiles]

great advice from above two tbh.

just try and find out what the type of screed that you had laid Bob. i would assume with a floor area of 270m2 this would have been pumped in, so you may be looking at an anhydrite floor.

 

[Time's Ran Out]

15 years ago the screed was laid!
So it's an early one if anhydride.

 

[jimthetiler]

If the floor is cement screed the joints will probably be at the door openings but not always.

 

[White Room]

If you cut all the way through the bottom of the door frames the screed is what holds them there other than the odd screw in the frame and depending what the door weights (fire doors etc) you have.

 

[bwel]

Hi All,

Thanks so much for all the rapid feedback and advise. I'll try and clarify a few questions below:

"Do u have any other reasons to think that the screed is unstable apart from the Amtico lifting?
Are there any areas of floor that sound different when walked on or tapped with your knuckles? (Hollows in screed)"

- There are some areas where I think there has been movement, eg where gaps between laid Amtico have occurred or the Amitico has stretched. Also there are some points where there is a hollowness under the Amtico. Ultimately, until its up I wont fully know.

"On a floor area that size, insertion of expansion joints in strategic places if not already in place.
Preferably through screed, or at least cause weak spots to try force it to crack where u want it to. It is possible, even with UFH."

- I'm not sure if there are any expansion joints. The area to be tiled includes multiple flowing rooms, some with Double width Door ways, that are always left open. eg Hallway to Sitting Room, Dining Room, Kitchen, Study, Cinema. Again guess until Amtico is lifted, I wont know what if any expansion gaps were incorporated.

However, if Expansion Gaps were set, it would be hard to make the 800x800 tiles edge at the right point eg a doorway. Also would it look odd if in a long run Titles were cut to align with a double doorway, where that doorway is allways open flowing between rooms ?


'Other things to consider are.....'

We have lots of storage and prep area, though its sounds like we will be living in a building site for a few weeks. We can however fits Dust Sheet doorways between work areas to try and protect dust air flow between floors and different areas of the house.

Thanks so much: 3_fall, impish, Lee@TileTown, timeless john, jimthetiler

Cheers Bob

 

[peteablard]

It's going to be hard to find if there are expansion joints in the screed as as there will already be a layer of latex over the screed before the Amtico was laid

 

[bwel]

It's going to be hard to find if there are expansion joints in the screed as as there will already be a layer of latex over the screed before the Amtico was laid

Any suggestions of methods to find expansion joints ? I'm not familiar with the latex layer,, is it soft as in rubber ? Could a thermal camera possibly find expansion joints followed by probing with a screwdriver or something like that ?

Any other ideas out there how to find and plan out expansion joints for the tiles ?

Many thanks