Cash coughed up some electrons that declared:


I had this problem on wall tiles in a shower quite some time ago [1], and
simply put more tile cement on the back of the tiles [2], but rather than
tap them in with a hammer, I simply 'wriggled' the tiles whilst pressing
down on them with hand pressure and then cleared the over-spill away - and
the things are still there 10 years later!


Thanks Cash.

I use the wiggle method on marmox as it's very difficult to press it down
evenly (large sheets). Wiggling it seems to give a better feel.

It's laying the marmox that seems to induce the lumpiness though. It'll be
worth it overall (for the warmer feet and damp resisting properties) but
it's bloody difficult getting a 1.2m sheet down without getting 1-2mm out
of true somewhere, even with using a 4' and 6' level as I go.

I might try laying the next batch cut in half (600x600 - more like a big
floor tile).

[1] There were some rather large indentations in one wall which meant
that these had to be filled with IIRC, finishing plaster (it could even
have been carlite) mixed with sand - and adding bigger lumps of cement to
the tiles really wasn't an option.

Luckily nothing that bad. The surface is generally true - just a couple of
mm here and there.

[2] Making sure that the cement was of a sufficiently 'soft' mix out of
[a
new, unopened pot - rather than using stuff that may have had the odd lump
or two in it.

Good point

Cheers

Tim