Wide grout gaps / Limestone - Tile Advice

[Shwancapstan]

Hi there,

This is my first post.

I've just finished laying approx 80m2 of Tudor white limestone with 6mm gaps. No major drama, but it has taken 6 months over evenings and weekends. I'm having a few issues with grouting. We want the grout to be flat, level with the face of the tile.

I some areas that the grout has sunk and cracked - I've obviously not pushed it in deep enough, and now swapped from Al-Murad's own make to some Mapei ultra colour, as apparently its more sandy. Now ive done one section that looks perfect, and the last 3 sections ive finished, can't seem to get the grout to stay flush with the tile face! I can't get the timing of the grouting / sponge off / smoothing over, and always leaves a dip perfect for catching dog hair and general detritus.

question 1 - what's the routine for grouting wide deep gaps?
question 2 - if there's a decent size dip, can I just grout over the top until its level?
question 3 - Lithofin / ltp matstone - safe to cover the grout? Solvent based, so could it damage it?
Question 4 - LTP iron wax satin as a final seal - anyone used it? Any good??

any help really appreciated. Pics...1st is what we are trying to achieve. 2nd is what we seem to be getting, 3+4 needs starting again, bit seems to have shrunk a lot (Hence changing to the Mapei.)

thanks
Sc.

 

[hmtiling]

Should have used a wide joint grout.
Is that a timber floor?
From the last picture looks like you have more to worry about than the grout

 

[Shwancapstan]

Hi, thanks for the reply, this is using wide floor grout, for gaps upto 20mm, and it’s only a 6-7mm gap. It is over a suspended floor, 18mm board, then boarded again the opposite way, and 20mm Ufh panels on top. I also replaced all of the joists, at 350mm centres. There is zero flex in the floor. Why do you say I have more to worry about?

 

[hmtiling]

Hi, thanks for the reply, this is using wide floor grout, for gaps upto 20mm, and it’s only a 6-7mm gap. It is over a suspended floor, 18mm board, then boarded again the opposite way, and 20mm Ufh panels on top. I also replaced all of the joists, at 350mm centres. There is zero flex in the floor. Why do you say I have more to worry about?

Although mapei ucp are suitable for that size joint a specific wide joint grout, like bal wide flex, would have been much easier.
The last picture looked like a crack from movement. Hopefully I'm wrong and it's shrinkage
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So it's a floating floor with ufh panels, what system is it? Are the panels fixed?

 

[Shwancapstan]

Although mapei ucp are suitable for that size joint a specific wide joint grout, like bal wide flex, would have been much easier.
The last picture looked like a crack from movement. Hopefully I'm wrong and it's shrinkage
[automerge]1587371623[/automerge]
So it's a floating floor with ufh panels, what system is it? Are the panels fixed?

[automerge]1587372627[/automerge]
Hi, I went round loads of tile places and nobody mentioned that! Just kept pointing at the mapei. So, I screwed the 2 boards together perpendicular, then it’s primed using Weber primer, the Ufh panels in the photo are then bonded to this. Pipes ran in and connected to manifold, Primed again then decoupling membrane, and tiled on top. There are no cracks, you can jump on it and zero movement. I think it’s just rubbish grout. I only used this in 1 area, and can get a lot out and the rest I’m going to try increase the gap with multitool and then use the mapei. However I still want to know a decent grout method for gaps this size / depth?? And I want to know if the lithofin is suitable over the grout (which is not cement based). Thanks again.
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[hmtiling]

[automerge]1587372627[/automerge]
Hi, I went round loads of tile places and nobody mentioned that! Just kept pointing at the mapei. So, I screwed the 2 boards together perpendicular, then it’s primed using Weber primer, the Ufh panels in the photo are then bonded to this. Pipes ran in and connected to manifold, Primed again then decoupling membrane, and tiled on top. There are no cracks, you can jump on it and zero movement. I think it’s just rubbish grout. I only used this in 1 area, and can get a lot out and the rest I’m going to try increase the gap with multitool and then use the mapei. However I still want to know a decent grout method for gaps this size / depth?? And I want to know if the lithofin is suitable over the grout (which is not cement based). Thanks again.
[automerge]1587372661[/automerge]
View attachment 112432

Bal superflex wide joint would be my choice for a 6mm joint.
Which grout isn't cement based?

 

[Shwancapstan]

Mapei ultracolour plus
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Mapei ultracolour plus

Sorry, not entirely true - it’s not Portland cement based!

 

[Perfect Tiling]

You'll always get a certain degree of shrinkage as the grout cures so not always possible to get the grout totally flush with the tile face with a 6mm gap....but in my opinion with this style of tile it looks better with a slight hollow to the grout as more natural. Make sure to seal the face of the tiles before you grout to avoid staining...then seal the whole floor once grouted. I'd also go with the BAP superflex wide joint...used it loads on limestone on joints up to 20mm and no issues.

 

[Shwancapstan]

Thanks - much appreciated. Perhaps we should keep the slight hollow. With almost 80m2 I just want it to be fairly
Maintenance free and find a way of keeping the grout clean and white?? And for any hiolllw that’s too deep, can I just
Put more in later?

 

[Perfect Tiling]

You should get a fairly even finish if you were to use the BAL grout. If you were to fill any hollows your'e not happy with....damp the cured grout first to stop the new grout drying out too fast. If your'e worried about the hollows holding dirt etc don't be....they shouldn't be that deep. When sponging the grout go across the joint rather than along its length and don't wipe too hard.....if the tiles are sealed before grouting any residue should clean off once the grout joints are dry....good luck