terracotta tiling onto chipboard

[jso]

We're fitting a new roof to 1970s sunroom, and incorporating an orangery roof lantern.
We want to tile the floor which is currently chipboard and carpeted.
Going to use small black and red, Victorian style, tiles.

I'm guessing we'll need to put something over the chipboard.
The no-ply stuff will be expensive - floor area is 25 square metres.
However, having just removed the suspended ceiling, I can see that the felted roof, which is going to be replaced, is plywood.

I'm wondering if I could recycle the ply to cover the floor and then tile on top of it. Thus reducing costs.

Obviously ply was the traditional approach, until the no-ply stuff came along, but is ply still OK to use for this purpose, or are there drawbacks to it which would make the no-ply panels a better option?

 

[foxhole]

Likely ply will be too badly damaged to re use also Likely to be warped and delaminating if of an age.

 

[jso]

Likely ply will be too badly damaged to re use also Likely to be warped and delaminating if of an age.

Yes, they are all possibilities. Guess I wopn't know until roof comes off. Also no idea what thickness - although assuming thick since it's a roof.

In principle, though, is ply just as good as no-ply? What are the supposed merits of the latter?

 

[foxhole]

Cement based board is unaffected by moisture and is far more rigid than ply .