how to attach roughcast to mesh (no bricks behind)

[HOUSEMARTIN]

Hi. We have a house built in 1932 and need to replace blown roughcast between the ground floor and 1st floor bay windows. Trouble is, the base render is fixed to steel mesh, with nothing behind it. The section above the ground floor window is okay as we removed the plaster inside and insulated last year, so it's solid. But the room above is not on our schedule to do for ages (can't afford to) so this section is going to remain uninsulated, and therefore not solid, for a while. How on earth am I going to get the render to stick? (And how on earth did they get it to stick in the first place - they must have mixed it with horsehair). I thought of putting a layer of hessian, or perhaps muslin as hessian might be too thick, on top of the mesh and the render will stick to that. What do you think?

[dougalhouse]

The render is mixed slightly stiffer than normal and applied to mesh. Not much sticks first time but whatever does is left to cure - 24 hrs or so. This usually provides a good enough key for a scratch coat.

Hope this puts your mind at rest!