Dural - Expansion joints ? - Tile Advice

[tomo13]

Hi, have I dreamt this or does using Dural / Ditra eliminate the need for expansion joints ? Customer looking at limestone but doesn't want any expansion strips. Is a concrete floor with UFH. Thanks.

 

[On one]

Wouldn't have said so.If the concrete slab has expansion joints in you need to follow that through the tiles

 

[AliGage]

Any expansion joints in the substrate still need to be replicated in the tiled surface.

If none then when areas exceed 40sqm they are required, and no area to exceed 8m in length without installing one.

 

[m3fitter]

This is correct.. but you'll find difference of opinions, i work for chartered architects and they all say different, i'm doing a church in newbury in September, and the architect states following expansion strips in line with the ones in the screed, with an 8mm expansion abutment at the perimeters, and then i'm working for an chartered architect in Kingston on a new build, and he states that ditra alleviates the need for expansion joints, note: they are both chartered ( which should mean the same standard )
rule of thumb: If there are expansion joints in the screed, follow then on the tile surface. full stop, if not, expansion on the tile surface only, will do nothing, or play safe and use expansion every 5m linear or through doorways with ditra. in a domestic instance, expansion joints look unsightly, in a commercial instance, it is a grey purchase, ie: its what has to be because the architect spec'd it.

 

[Diamond Pool Finishers]

M3 would i be correct in thinking that if an architect designs the expansion joint layout then they take responsibility for it ?

 

[tomo13]

So does the membrane have to have a join where the joints are or go over then a joint in the tiles where the joint was ?

 

[m3fitter]

M3 would i be correct in thinking that if an architect designs the expansion joint layout then they take responsibility for it ?

correct, in theory, but in practice, you follow, what has physically been laid in the screed, photo it

 

[m3fitter]

So does the membrane have to have a join where the joints are or go over then a joint in the tiles where the joint was ?

No because you are creating a floating floor, in lateral movement, therefore the screed takes care of itself, and your floating floor moves independently, it decouples

 

[tomo13]

Are we talking expansion trims or a silicone joint or something else ? Its going to be brick bond, so would run through the tile top to bottom not along a joint, not going to look nice really. looking at the screed today, all there is are lines in the screed about a disc blade width, surely it should of been bigger than that and with something in it if it was going to do any good ? Any photos of your previous would be nice to see.

 

[Mr Tiler]

This is correct.. but you'll find difference of opinions, i work for chartered architects and they all say different, i'm doing a church in newbury in September, and the architect states following expansion strips in line with the ones in the screed, with an 8mm expansion abutment at the perimeters, and then i'm working for an chartered architect in Kingston on a new build, and he states that ditra alleviates the need for expansion joints, note: they are both chartered ( which should mean the same standard )
rule of thumb: If there are expansion joints in the screed, follow then on the tile surface. full stop, if not, expansion on the tile surface only, will do nothing, or play safe and use expansion every 5m linear or through doorways with ditra. in a domestic instance, expansion joints look unsightly, in a commercial instance, it is a grey purchase, ie: its what has to be because the architect spec'd it.

I watched a programme online about the stone masons who built the churches in this country... they basically used the same principle as ditra matting but with sand that is how they were able to make such floors. they didn't need the expansion joints for there floors so why would we need them on ditra? real question not being sarcastic if t seems that way sorry

 

[SJPurdy]

So does the membrane have to have a join where the joints are or go over then a joint in the tiles where the joint was ?

Quoting from Dural Special advise leaflet; "The matting MUST be split at the movement joint"

 

[On one]

Do you mean the concrete has been laid,cured and someone has Stihl sawed a line/cut in the screed?
Is it possible for the expansion joint to placed under a door? ie to less intrusive

 

[tomo13]

Do you mean the concrete has been laid,cured and someone has Stihl sawed a line/cut in the screed?
Is it possible for the expansion joint to placed under a door? ie to less intrusive

Yeah looks just like that, is that normal ? I'm trying to find a way to get a copy of the plans on here so I could get some opinions of where to put them ?

 

[tomo13]

Thinking about it they would of had to go pretty steady to avoid the UHF !

 

[The D]

Ditra / Dura is NOT a replacement for an expansion joint it is a crack isolation mat and allows only 3mm of lateral movement. If there is an expansion joint in the sub- floor you must follow with an expansion joint in the tile.