On 2006-07-30 22:03:51 +0100, DJC said:

Andy Hall wrote:
On 2006-07-30 16:06:47 +0100, John Rumm said:

Andy Hall wrote:

For a wall mount pan, I am wondering whether to go for ply or
plasterboard (ply seems to make more sense as less risk of crushing)

You may get a slightly higher point load at the base of the pan due to
its leverage effect, but I can't see it being much of an issue as long
as the substrate is absolutely rigid and the tiles are fully bedded on.

I was thinking of 18mm ply, but perhaps something thicker should be used?

Were you not intending to use a Grohe frame? If so the load should be
taken by the frame, in which case 18mm ply would surely be sufficient
to ensure the layer of tiles remain flat and rigid.

Yes I am going to use a Grohe frame. My natural thought was that
18mm ply ought to be fine - I was just floating this one in case
somebody suggested that something more substantial would be needed and
had a reason for it.