Replacing cracked ceramic floor tiles

Hello
I have a couple of ceramic floor tiles (approx 12"sq) that I need to replace in an upstairs bathroom due to hair-line cracks.
I wondered if anyone could offer any useful tips for replacing the tiles without damaging their neigbours? I'm fortunate to some extent in that the two tiles are adjacent to each other and are at the edge of the tiled area next to the bath panel. My initial thoughts are to drill the centres and try to work out from there.
With hindsight I'm regretting tiling an upstairs floor, but all reasonable precautions were taken - the floor was fully-reboarded with thick-ply (with lots of screws). I'm hoping that any movement has stopped now, but obviously I'll be taking a close look under the tiles.
Thanks Thomas

Thomas wrote:
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Done it a few times.
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Scrape out the grout with a stanley knife or grout remover all around the neighbouring edges. Then do as you say above. Work from the centre out & take things carefully & you won't crack the adjacent tiles.
Good sharp scraper to remove the old adhesive. Fix the new tiles with No Nails or similar & you can grout more or less straight away.
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Personally I think tiling on a wooden floor is a very bad idea no matter how well you try to do it. Asking for trouble.

On 26 June, 00:10, "The Medway Handyman"
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The guy who laid my tiled floor had to come back to replace a cracked one and just broke it with a hammer and removed the bits.
On one hand I agree with TMH, though I don't agree that it is a "very bad idea" I think the error lies in laying tiles that are large. I really like my tiled bathroom floor and I would do it again, but I might look for a smaller tile so that there is less stress on each tile.
Rob

Rob G wrote:
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Good point Rob. I shall ammend my comment to "Personally I think large tiles on a wooden floor are a very bad idea no matter how well you try to do it. Asking for trouble."

The Medway Handyman wrote:
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The secret is three fold.
1/. stiffen the floor a LOT.
2/. use a very THICK bed of flexible cement.
3/. Don't dab and dot it. Use a proper bed and take time.
By doing this on two upstairs bathrooms, the original cracked tiles were replaced, and no further problems.

On Thu, 25 Jun 2009 23:10:12 GMT, "The Medway Handyman"
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Since we're on the subject, can anyone offer some advice on this one:
When I connected my washing machine (three years ago now) I made a boo-boo. I didn't check a day or two later that the hose connections were absolutely leak-free. Many MONTHS later I discovered that one had a drip, but one so minor that it could have amounted to no more than a drip a day. Absolutely minimal. No trace of water on the tiled annexe floor where the washing machine is located.
And then I began to notice a musty smell in the adjacent downstairs loo. Didn't connect that to any leak, just thought, oh, well, I don't use the annexe much anyway. Probably need to open the window more often and let the air circulate a bit.
And then a floor tile developed a hairline crack. Bugger! I thought. Still didn't think anything about the w/m though.
Finally, I just happened to be cleaning the tiled floor and noticed that the grout in the vicinity of the w/m was wet even though I hadn't got that far with my mop! I pushed down on the tiles and water squeezed out through hairline cracks in the grout! Omigod! What's happening?
So I removed the kickboard from beneath the annexe sink unit into which the w/m is mounted. Underneath just concrete, and the concrete was sopping wet.
I had finally, months after installing the w/m, discovered a leak!
Well, after fixing the leak, the underfloor dried out pretty quickly. Matter of days only. BUT....
...The tiles, even though downstairs, are mounted on some kind of chipboard base, with the chipboard laid on top of the concrete. Perhaps this is the way modern houses are built - or just the ones on this estate. There is a layer of black plastic, then the chipboard, then the tiles.
The chipboard got damp, swelled, and the tiles cracked (two of them) and lifted. Before I sell the house I'm going to have to do something about it, but what? Could I remove the tiles closest to the w/m, fix the swollen, now dried out chipboard, then replace/renew the tiles? Or will the entire annexe tiles have to come up and the chipboard replaced across the entire floor area? The annexe is tiny. About enough room to swing a small cat in. So we're not talking about a major job.
MM

MM wrote:
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Ok. I had a similar experience. Swelled chipboard and cracked up tiles.
This is what worked for me.
First, fix the leak.
Then remove anything that is loose. In my case I went for a room re-tile anyway.
Then LEAVE it for a LONG time till its all properly dried out.
If the chip dries flakey, seal with dollops of PVA. It will replace the original bonding and make the thing good,
Leave to dry agfain
Then re-tile.

On Mon, 29 Jun 2009 15:09:10 +0100, The Natural Philosopher
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Thanks. It doesn't seem quite so bad when one gets a second opinion!
What is the purpose of the chipboard (ground floor)? Insulation? Otherwise I thought floor tiles were laid directly onto concrete or screed.
MM

MM wrote:
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No idea. Possibly to get the levels right.
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Many thanks for the helpful replies. I'm hoping to have a shot at replacing the tiles this w/e - I'll report back.
Regards Thomas

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Scrape grout out using grout scraper, drill hole in centre of tile and use hammer and tineist cold chisel possinle remove tile working from drilled hole outwards.
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wrote:
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Scrape out grout. Drill it a few times before then use gently a small cold chisel.

Hello all.
Well I managed to get this job done today and it was a lot easier than I anticipated.
I began by scaping out the grout between and around the 3 cracked tiles which were all adjacent. Rather than drill through the centre of a tile I used a screwdriver in the gap between two cracked tiles to lever one up. The tile I chose was split in two by a crack and fortunately one half came up cleanly. After that I just worked my way around with a scraper and had all three up in a few minutes leaving behind almost all of the adhesive. I noticed there were quite a few hollows in the adhesive - not quite dabs and spots but certainly not a continuous bed! I also noticed that the contractor had placed ashort wooden noggin at the edge of one of the cracked tiles which was taking some load from the bath. I couldn't see the need for this and I strongly suspect it had caused the cracking so I removed it.
The old adhesive looked in pretty good nick so rather than try to chisel it out I decided to fill in the cavities with more flexible adhesive and skim a very thin layer over the top. Then I just popped some fresh tiles back in place, grouted and re-siliconed the bath panel back. All feels nice and firm, but only time will tell!
Thanks Thomas