Hi
I'm (self)-building a garage /workshop and living room extension, and the next stage is rendering the outside blockwork of the garage. It's built of dense 7N concrete blocks, 100mm, cavity wall.
I'm fairly confident at internal plastering with gypsum plasters, but never rendered a big area outside before. I have an electric mixer.
Looking for advice:
Wall preparation - do I need a dilute PVA coat?
Wet the wall before applying scratch coat?
Render mix - I'm thinking scratch coat 4:1 sand:cement with render plasticizer - yes? What kind of sand? About 5-7mm (walls are pretty straight!)
How wet to mix the s&c?
Scratch the base coat but not right through to blockwork.
Next day
Top coat 1:1:7 cement:lime:sand - what sand? About 3mm?
Finish with sponge or float?
Thanks
I'm (self)-building a garage /workshop and living room extension, and the next stage is rendering the outside blockwork of the garage. It's built of dense 7N concrete blocks, 100mm, cavity wall.
I'm fairly confident at internal plastering with gypsum plasters, but never rendered a big area outside before. I have an electric mixer.
Looking for advice:
Wall preparation - do I need a dilute PVA coat?
Wet the wall before applying scratch coat?
Render mix - I'm thinking scratch coat 4:1 sand:cement with render plasticizer - yes? What kind of sand? About 5-7mm (walls are pretty straight!)
How wet to mix the s&c?
Scratch the base coat but not right through to blockwork.
Next day
Top coat 1:1:7 cement:lime:sand - what sand? About 3mm?
Finish with sponge or float?
Thanks