Tiling over concrete patio slabs

[demotedreally]

We are just having a summer house built with a patio out front. The patio is boring concrete slabs. I want to tile over them with something fun.
Seems totally simple - few tiles, bit of grout that will be ok outside.

Am I right?

You're supposed to pull them up rather than tile over, not sure how it would sit if you don't do that.

So what base would you need to tile on? There is only compacted earth underneath - that won't work

@demotedreally we are doing the same - garden room and concrete patio. Yes we will be laying tiles on top of the concrete base.

You'd need to be sure each slab was totally level... Not sure how likely that would be. Otherwise you'd need to remove and pour a concrete base.

By tile, presume you mean porcelain. You can't overlay them on your existing slabs.

You need to take them up, dig out that compacted earth and compact a new sub base from lime crush or MOT1. Then you can prime and bed your tiles on an even bed of strong mortar.

If you had a suitable existing concrete patio or path you could tile over that.

Hmmmm, as I say we won't be taking the slabs up, they were laid yesterday. They are very cleanly flat.

I'm wondering what the issues are - breakages over the joins presumably? Perhaps I can get tiles that are the size of the slabs and that will mitigate it

Why didn't you just get tiles put down instead of the slabs?

You will need to take them off, dig, base down and then tile.

What about painting them rather than tiling over the new slabs?

We had them laid for a huge summerhouse with a patio bit on the front. I'm not going to be destroying all the work for a bit of pretty. I'm still not too sure of the problem people are raising

I'd stencil and paint the concrete slabs rather than put tiles on top of them.

The problem is simple, over time the slabs will move slightly as they aren’t on a concrete base. When the slabs move any tiles laid on top will crack.

They'll crack. No chance they won't. My dad used to have a landscaping company, they need to have a 100% flat base, no covering over joins etc. It's no good saying they look flat, they need to be smooth and flat.

So I have measures the slabs and they are 30 cm. Presumably then I can stick one 30 cm tile on top of each

Garden Rescue lay tiles over existing slabs all the time! If it's good for the Rich brothers, it should be ok!

They don't show you how it looks after a few months.

No, the bottom ones will move. You'll have to take them up. Otherwise I'm a few months they'll crack.

In theory yes if your tiles are the same size as your slabs then the tiles shouldn’t crack due to the slabs moving.

you may however have a problem with different expansion/contraction rates in hot or cold weather. Everything shrinks/expands in hot and cold and if your tiles shrink/expand more slowly or quickly than your slabs, and you’ve cemented one to the other, there’s going to be a problem. You might be able to solve this by laying Ditra matting down over the slabs first.

you will also find that gaps open up between the tiles, and they end up a bit wonky, due to movement of the slabs. This tends to look ok with garden slabs as they aren’t expected to be fully flat and smooth forever but could look a bit rubbish with tiles especially if they are not a rustic design.

Stencilling/painting the slabs is IMO a much safer and better option…

Paint and stencil over them , as a PP said. Tiling is a bad idea.

Can’t you just put a temporary frame around the slabs and pour a tub of that self levelling concrete over, then tile on top and remove the frame?

Er thanks for this. Have you seen our garden or is this a more general comment?

So this stencilling business. Does it looks good? I want something nice and bright. Any pictures or suggestions how to do it?

We had a similar challenge. We built decking over the concrete to cover it and make it interesting. The frame didn't need additional concrete blocks below.

Yes! I have just realised that interlocking tiles is the answer!!

OP I have to laugh because you have come in and asked a question, everyone has given you advice and explained the problems, including people experienced at landscaping, and you insist that you are right and they are wrong...so why did you ask? 😂

Interlocking tiles on top would be like building a jigsaw puzzle on an uneven surface. Stencilling and painting is your best bet. Or just lift the concrete slabs and put nicer ones down.