Replacing plaster on 107 year old Dormer window

[WLF85]

Hi All,

I'm currently restoring a Dormer on my old Edwardian property and the roughcast (or pebbledash?) render on the sides is completely blown and crumbling in my hands, and the lathes behind rotten.

The property is very high (3 stories) so I'd like to take a stab at replacing the plaster myself as I can get away with some cosmetic imperfections (you can hardly see it from the ground).

Note that I can see all the timbers from the inside and they are in good enough condition, it's just the lathes that need replacing.

I'm a newbie to plastering so could use your advice.

What would you do after removing the old plaster?

- Replace the lathes and plaster in lime?
- Use modern plaster?
- Some other solution?

Thanks a lot for your help and guidance.

 

[roy c]

I would knock all the plaster off check the studs and give them a good spraying with wood preservative, then put some building paper over the out side area (double it up if you like). Then cover it with stainless mesh (2 pieces ) fixed to the studs. Then you can spread a coat of sand and cement (5-1 with w/proofer in the mix) over the mesh it might take a couple of coats to get it flat. Then when you are happy with it scratch it with wavy lines. Let it go off for a day or two then mix up a (5-1-1 mix) sand, cement, and lime. and get it to a nice consistance and lay it on, get a piece of timber and flatten it out, add more muck to get it flatter if you have to. Then leave it for an hour and gently float it up then when your happy sponge it up. Hope this helps...Also you might find some lead soakers going up the edge of the tiles. If so you might have to reset them in with your render work...

 

[vinn]

As the detailed reply above.
Except that for a DIY'er it might be better for him to fix a piece of ply to the studs as backing for the felt and mesh?

However OP, you might find that there's more rot than meets the eye once the render is stripped?
You will have to lift the tiles close to the dormer cheeks - discard any too stained or stuck with mortar.
The upstands on the soakers should be about 50mm min - or pin a strip of cover flashing to come down over the soaker upstands.
Dont bring the render right down on to the tiles leave a gap of about 35mm to prevent capillary creep.

Sort the gutter(s) by dropping and clipping a length of down pipe to discharge beyond the dormer face - into the main gutter would be best.
OP, you will have to think seriously about safety arrangements when working on the roof - 2 people, & roof ladders are a must. Consider traffic on the street below?