Been to look at a job the other day and im not sure how to go about it. The job is rendering a dorma on the roof of a house, the dorma is constructed of wood and lined on the outside with plywood. Any suggestions on rendering it? Is krend the way to go?
Dean. You need to know what you are doing. When this was done on our loft conversion, the plasterer first stapled a sheet of Tyvek (synthetic roofing felt) over the ply. Then he stapled - securely - SS mesh over the surface, and rendered on to this (make sure you fit the mesh the right way up - one way will 'catch' the render, the other way will allow it to slop off!) I must say I was surprised by this method - the render does not bond to the actual ply, but is practically a floating surface. Applied in two layers, like 'normal' rendering (scratch and top).
Thanks for the replys sammy toaster and devil's advocate, Will give it a go with the mesh, I was thinking of using the self adehsive rendering mesh instead of the wire mesh, any thoughts on this?
Hi Dean. I have to say I've never heard of self adhesive rendering mesh. Although the render will be effectively 'self-supporting', the staples clearly play and important part in how sturdy the whole thing is. I don;t think I'd be happy with self-adhesive stuff - but I know nothing about it! Also, it would mean you wouldn't be applying a layer of Tyvek first? (Ask on the Builders' Forum!)
I've seen this stuff in action and it is superb http://www.wethertex.co.uk/html/grc_renderinformation.html
Rendered plywood, it will come back to haunt you. Ideally it would be better to cover ply with Knauf Aquapanel Exterior Cement board, render can then be applied directly to it.
Many LAs now want riblath over 25 thick battens to provide an airgap rather than just eml. I would use screws with big washers to fix eml if you can use it, over breather membrane as above, all the weight of the render is going to hang off them