A little bit of advice please, regarding a suitable rendering substrate (see the Eurocell uPVC cladding in the photo below). Will be rendering over the pebble-dash (after removing and filling the areas that have blown) - though also want to smooth render the Eurocell PVC area, so the rendered finish is consistent. The PVC is set-back about 5cm from the pebble dash, hence the requirement to build-up the area in advance. Was thinking battens and boarding over the top of the UPVC, and then a mesh / primer / etc. build-up on top. However, not sure what boarding to use (hardwood ply, with a weatherproof seal on the edges?). So throwing it out there, what would anyone suggest? Doesn't need to look pretty - but does need to be functional.