Thanks for the Sanity check on my plans to extend my trailer.

It occurs to me that it might be good to use the same material for
building up the sides of the box as is used for the base - Phenolic
ply.

However, the only place i've so far found it for sale (only looked on
the web so far) is at Indespension and they want £80ish a * x 4 sheet!

Does anyone know if this stuff is available cheaper elsewhere?

Failing that, I think WBP is prolly my next best option, anyone got a
guide price for an 8 x 4 sheet of this (16mm??)