Quarry Tiles on Concrete

[thebadger7]

Hi all

We've got a 3m x 4m new kitchen - extension on Victorian property with new concrete sub floor (including 100mm insulation). We've salvaged some original chunky quarry tiles from the project, 30-40mm deep that we intend to lay back on the subfloor. Mainly for the aesthetics rather than breathability.

Unsure what to do with grouting - as previously they were laid together. Any thoughts? Also not sure what to lay them on - they're different thicknesses so was considering a bed of NHL to allow for height differences.

Also considering whether to install UFH or not - mainly whether it's worth the cost (£3k). I know quarry tiles can be cold underfoot - presumably this would be better given the insulation?

Any thoughts gratefully recieved.

Thanks

Luke

 

[Cubist]

I would be concerned with the quality of the bond between the concrete subfloor and a lime based cement. Typically they don't work well together and, while others may have a different view, I suspect you may experience problems with some tiles becoming detached over time and that can become a major headache. Clearly you would not consider excavating the concrete so I would suggest that you should use a cementation adhesive on which to bed the quarries and use the same material as a grout for the final finish.

As to UFH, my thinking is that the heat differential induced between the quarry bedding material may, if a lime based product were used, contribute to failures of the bond to the concrete slab. Frankly, I would err on the side of caution and want to do more research and talk with someone with direct experience.

 

[thebadger7]

Thanks Cubist makes sense - yes we didn't go with a limecrete floor as all adjacent walls are newly built cavity walls with DPC.

 

[stuart45]

I've laid different thickness tiles on very uneven floors using a sand/cement mix with no issues.
Wall tiles used to be put on with sand/cement until more recent years.
If you ever have to remove tiles out on with a sand/cement mix, you can tell the difference.

 

[malcolm]

My woodburner is arriving next week so I'm urgently planning to get around to doing a hearth of quarry tiles on a cement base. Pamments are reclaimed and I don't want to do anything to stop them from being reclaimed again. Any of the modern cement based stuff will be very difficult to clean off the tiles so I'm planning to use a lime mortar.

 

[thebadger7]

Thanks all. Be interested in how you get on Malcolm, what grout size are you using?

 

[malcolm]

Thanks all. Be interested in how you get on Malcolm, what grout size are you using?

I'll lay them out and see how uneven they are before figuring out spacing. The existing pamments in the living room are spaced about 10mm apart.

 

[thebadger7]

Makes sense. Mine are different thicknesses so going to be a challenge to lay. What you going to use for the tile cutting?

 

[Cubist]

Diamond tile saw in a chop saw or angle grinder would be best - the former is the safest. Get ready for a dusty, noisy time and plan to make as few cuts as possible.

With tiles of different depths the final grout bed depth will rely on the thickest tile you need to lay. Disaster awaits the person who leaves the thickest to last. Best start with that one and lay the grout for the others based on the level from that tile. Also, its wise to check that level with any door openings and other obstructions to avoid other gotchas.

 

[stuart45]

The most important tile you lay is the first one.

 

[thebadger7]

Great, I was planning on doing a diamond pattern which would mean tile cuts at the edges, but maybe I'll stick to square pattern to minimise cuts. I've got an angle grinder.

 

[stuart45]

Think about what you really want. You'll be looking at it for a.long time, so the extra work might be worth it in the long run.

 

[Cubist]

Great, I was planning on doing a diamond pattern which would mean tile cuts at the edges, but maybe I'll stick to square pattern to minimise cuts. I've got an angle grinder.

Make sure you can firmly clamp the tile to avoid the blade skating. Oh, and keep your fingers out of the way and count them afterwards.