Expansion Joints Advise Please

[KL Tiling]

Morning people!

In a few weeks time I have a new build house to tile.
The total area is about 220sqm.
The downstairs floor is about 120sqm and will be tiled using Limestone in free length.
The screed is completely dry (sand/cement) and the surface is like a snooker table which I'll prime first of course.
There is wet ufh under the screed and I will be installing Schluter Ditra on the whole area.
Although the entire area is about 120sqm there is no single area greater than 21sqm. All rooms are therefore connected by an entrance hallway.

My dilema is therefore should I install expansion joints?

The customer would prefer not to but would of course if advised to do so.
If necessary I'd probably put them in doorways but personally (and because of the Ditra) I don't think they are absolutely necessary.

What do you guy think?

Thanks, Karl

 

[nybor62]

i would put expansion in the door ways , and also a perimeter expansion of about 3-5mm

 

[Brian the Tile]

yes definatley expantion joints in all the doorways with a Silicon joint

 

[Ajax123]

Expansion joints required by British standards. Also based on common sense. Here should also be joints in the screed. Snooker tabl flat I struggle t accept. If there are no joints or cracks are you retain it is sand cement screed?

 

[Pebbs]

Actually he doesn't have to legally put expansion joints in because the largest area is 21m2. But this is a new build and for sure theres going to be some movement, I would go with what someone else has said and soft joint it, if they are dead set against these expansion joints. But make sure you get a disclaimer signed, just to cover yourself.

Pebbs

 

[Dan]

Just the fact there are different rooms with different heat-loss values means different expansion/retraction rates in them all means they have to be used in doorways though, right? Or does that not apply if the rooms are still 21m2 or less?

 

[KL Tiling]

Thanks guys.

There are joints in the screed where it has been laid in sections. These are in doorways.
The screed has been extremely professionally laid and is very flat and even

Even with the Ditra I'd be tempted to have expansion in the doorways as, like you guys have said, although the largest area is only 21sqm the total is still about 120sqm. All the areas are connected via doorways so doesn't that make it one large area strictly speaking?

A perimeter expansion isn't a problem as the floor is being laid before any carpentry is installed so a 5mm gap will easily be covered by skirting etc.

Over such a large expanse I realise of course that it should have expansion joints but to a degree we do what the customer wants (provided you get that all important disclaimer).

 

[Ajax123]

Sorry but a disclaimer is not worth the paper it's printed on in a domestic client vs professional tiler relationship. If it goes wrong and you have failed to follow what is considered industry best practice you will be found liable, disclaimer or no disclaimer.

You cannot and should not seek to shirk your responsibility to do the job correctly and you cannot legally shift your responsibility to do so. If you do it wrong knowingly you cannot enforce a disclaimer.

That Said I agree that the client often does not want what is correc so you have to make a balanced judgement based on the levels risk and if the risk is worth taking or not.

All joints in the screed should reflect through the tiled surface. Ditra matting is not designed to mitigate the risk to the tile face of bridging joints in the substrate. The ditra should stop either side ofthe joint and the joint should run up through the tile face. That is what the industry considers to be best practice.

 

[KL Tiling]

As a professional I would never in any way try to shirk my responsibilities or look for an easy way out. That's why I asked the opinion of everyone on here. Isn't that what this forum is for?

If most of my fellow professionals believe that expansion joints are a must then that is what I'll suggest to my client (we have already had this discussion and I said I'd find out for sure).

Also, I am fully aware that one industry pro will have a different opinion to the next and the pro's will even disagree with the manufacturers etc etc. That's why it's good to have these discussions isn't it?

 

[Ajax123]

I agree. However the codes of practice which are a distillation of the opinions of "experts" and as such in the event of a problem they tend to over ride the singular opinion of one pro tiler. Unfortunately I find that different standards are in conflict with each other much of the time. Bloomin nightmare.

I would not seek to suggest that you would shirk your responsibilities. I just wants to make the point about disclaimers.

 

[CptPugWash]

would put em in if they are in the screed :ninja: