Cracked Tiles

snipped-for-privacy@aol.com ( snipped-for-privacy@aol.com) wibbled on Monday 14 February 2011 17:09:

Hmm. I don't think tiling T+G is a good idea - ideally it would have been oversheeted with suitable ply.

That's not really a retro fit option here, so I would get some of the best "flexible" adhesive you can find (eg a Mapei or BAL product) - look for "suitable for wood" and/or "Class S2".

Ditto grout - needs to be a flexible type.

Sometimes these are ready to mix powders, sometimes powder + liquid additive

- eg Mapei Keraquick + Isolastic and Keracolour grout + Fugolastic additive (Mapei again) - those are what I used when tiling onto non rigid substrates.

Of course, washing mashines do present a high dynamic load - have they cracked under the feet in its normal operating position, or just somewhere away from it where you dragged it over to pull it out?

Cheers

Tim

Yes - whoever did your tiling should have done it properly.

Personally I'd take up the floorboards and put down 3/4" WBP plywood and tile to that.

Actually - I wouldn't tile on a wooden floor at all, and certainly not upstairs, but that wasn't what you asked!

very good question - if it's just around the feet, it might be possible to sit the appliances on something more sturdy that can spread the load, along with some form of flexible layer between that and the tiles to even things out. Cheap to do and worth a try, I think.

The alternative would be to tear things up and start again with a suitable backing layer - if this was done by a commercial firm maybe there's potential to seek compensation through the courts.

cheers

Jules

You will probably always have problems with it. Tiles don't bend whilst T&G boards do. When you do replace them make sure you get an even layer of adhesive under the tiles so as to support the tile evenly. Cracking in high load areas is not uncommon even on solid sub floors when the adhesive is not evenly supporting the tile.

Mike

you are most likely screwed.

Only way to work this is a very stiff floor, thick flexible cement and hope the grout is a bit flexible too.

If the floor is bouncy, nothing will work.

Its no worse than ply: the secret is the joist size/spacing and herringboned noggins..

thin ply sheet and 25-50mm floor grade extruded styrene sheet.

yep

I would, and did, but only after some serious structural stiffening.

Neither would I. Bad idea in general. Agin nature.

Years ago a friend covered a bedroom floor with cork tiles. Within weeks he had to lift a chunk to get at some wiring beneath.

That and T+G that's in good condition - free of wear and warping (I've seen some right banana-shaped stuff in places that can be subjected to high levels of moisture - such as kitchens. Screwing down ply (or cement [1] board) just compensates for some of the slight imperfections. Like you say, if the joist spans or spacings are too big and they're allowed to flex too much then it's game over no matter what you do.

cheers

Jules

Would ply be prone to wear over time? I'm really not sure - OK for a static fridge, but I don't know if it'd come apart with a washing machine rumbling away on top of it. I was thinking something along the lines of some 1/4" steel running left-right or front-back between feet, and sitting those on some thick rubber sheet. Maybe the OP can experiment for a few months before fixing their current tiles.

cheers

Jules

Brother has just had a bathroom floor laid on 'Plastic Ply' a sort of plastic mesh by Nicobond. Tiler claims its the puppy's plums. I remain to be convinced. They have a website at

It does have a massive disclaimer though

"IMPORTANT NOTES: Existing wooden floors must be rigid, stable and capable of supporting additional load without flexing and have sufficient ventilation beneath them. Any loose boards should be secured prior to applying N&C Nicobond Plastic Ply. If there is excessive flexing or movement within the floor the addition of extra noggins may be required".