On 04/02/2019 13:01, www.GymRatZ.co.uk wrote:
On 04/02/2019 12:10, Jim K.. wrote:
Apparently something of a no no, but has anyone tiled onto MDF
successfully?

It's a window reveal in a kitchen. Old tiles detached, hardly any
old adhesive stuck to the MDF underneath.

Wondering what to use to stick them back?

Not MDF but I've had a problem with the floor tiles I laid onto green
chipboard.

Originally we were simply going to extend the wood flooring into the new
extension then, like they do, the good lady changed her mind and wanted
tiles.
To cut a long story short I'm still waiting for any remaining tiles to
loosen. The ones that parted company so far have all been over the end
joins of the chip board.

Needless to say my favourite anything-to-anything building adhesive has
been used to re-attach the tiles to the floor.
Gun Grade expanding foam!

Where possible I left securely fixed tile adhesive on parts of the tile
to give correct height alignment with adjacent tiles. Sanded top surface
of chipboard to remove any waxes etc., mist chipboard and tile underside
with water, apply foam to back of tile and position. Add a few weighty
weights that overlap to surrounding tiles to ensure the foam doesn't
have chance to expand and lift tile and leave long enough for foam to
fully cure.

Still haven't grouted the tiled floor yet but the tiles that have been
re-fixed with foam are very solid and the one I did try and re-lift
wasn't coming up without breaking so I left it alone.
#

This is all about flexure.

I had similar and retiled using a thick (5mm) bed of FLEXIBLE adhesive.
No more issues.






--
"What do you think about Gay Marriage?"
"I don't."
"Don't what?"
"Think about Gay Marriage."