We bought a Victorian terrace and hoping to DIY a large part of the renovation (I am self-employed with a lot of time on my hand and some experience in DIYing so it seems like a good option). My question is concerning plastering: I have decided on hard plastering, straight onto the brick. The question is as follows: I have read many guides and they say I need a first layer of about 10-12mm and a finishing coat of about 2-5mm. However, the backbox of power sockets and light switches is 25mm. What would you recommend I do? I was thinking two coats of 10-12 each, then finishing with 3mm, bringing the total to 25? Or should I go with one think render on the brick (20mm) and a finishing coat of 5mm? Also, do you recommend I do a thinner coat on walls with no sockets/switches? PS: I would be incredibly grateful for product recommendations for each step.
Why not insulating board stuck then hammer twist fixings? Just asking. Charlie diy on youtube done one but I'd add mechanical fixing. I tight with heating cost. Ha.
Yeah it is more solid but not as good for insulating. Also cracks will start to appear as the property moves. People do like the old style building methods but truth is its not always that good vs modern methods of making things air tight with insulation. Gypsum can pull moisture in old properties creating damp so make sure it's all dry with cavity walls. When I do those I dot and dab strips of plasterboard as guides for the hardwall or bonding. Drag straight edge to level across the stuck strips
The plasterboard as guide idea is amazing! Thank you so much! I'm aware that gypsum can crack and considering lime plaster as I believe that's better for houses built pre 1850.
I also have 100m x 1m plastering mesh for spider web cracked old walls.. Its good stuff and I buy from one stop plastering shop. You lay in multi finish
Use insulated plasterboard on externals, ideally on battens. As long as internals are ‘problem free’ then use hardwall plaster as your float coat. Set up dots which are basically small squares of Pb or wood stuck on and levelled up with a straight edge/level and string line. Use these to keep the wall flat/straight as you use your feather edge. You need to put on a scratch coat first, then build up the layers to required thickness. Too much and it could slump.
I'm surprised that none of the answers mentioned this, but usual practice is to chisel out some of the brick so that the back boxes are partially sunk, leaving them proud ~15mm or so (whatever the final depth of plaster is planned to be).