In article ,
Pete C writes:
On 30 May 2005 00:36:42 GMT, (Andrew
Gabriel) wrote:
The water resistant chipboard for bathrooms survives wet for ages,
much to my surprise. Things like the carpet grippers had all rotted
away, but the chipboard was still rock solid, in spite of being wet
possibly for a year or more, and supporting an internal thermal
block wall (also wet right through).

Sounds good, did it warp or expand much?

Not at all. I was worried about the wall built on it dropping,
but it hadn't. I don't know if there are different qualities
of waterproof chipboard. I think the whole upstairs floor of
this house (about 15 years old) is built with it.

I suppose a good test for flooring chipboard is to boil a sample or
give it a cycle in an old dishwasher.

That sort of heat might have other effects.
Just leave a piece outdoors and see what happens.

--
Andrew Gabriel