Hi all, I have been a member of this site for a number of years and have greatly benefitted from the advice and information gained, many thanks. I have successfully tackled internal plastering finishing whole rooms from top to bottom on bare blockwork and plasterboard.
However, I have come unstuck on my first attempt at the external rendering of a blockwork boundary wall (7n2). The first coat stuck well 4 to 1 TP plastering sand/Mastercrete cement plus 3in1 additive, applied approx 5-8mm scratched up and keep moist for a week.
The second coat 5-1 plus 3in 1 additive was applied to a slightly damped up surface at about 8-10mm, ruled off level with a feather edge left to partially set floated then sponge to finish. Again kept damp for 3 days. After about 5 days hairline cracks appeared and the render started to blow, the first coat still seems solid.
Where did I go wrong?, was the 2nd coat too thick? I know I added too much 3 in 1 additive to the first coat, I didn't use any lime or fibers ( locally not available).
Any help is greatly appreciated, I know I will have to completely strip the second coat and maybe do an SBR job?.
However, I have come unstuck on my first attempt at the external rendering of a blockwork boundary wall (7n2). The first coat stuck well 4 to 1 TP plastering sand/Mastercrete cement plus 3in1 additive, applied approx 5-8mm scratched up and keep moist for a week.
The second coat 5-1 plus 3in 1 additive was applied to a slightly damped up surface at about 8-10mm, ruled off level with a feather edge left to partially set floated then sponge to finish. Again kept damp for 3 days. After about 5 days hairline cracks appeared and the render started to blow, the first coat still seems solid.
Where did I go wrong?, was the 2nd coat too thick? I know I added too much 3 in 1 additive to the first coat, I didn't use any lime or fibers ( locally not available).
Any help is greatly appreciated, I know I will have to completely strip the second coat and maybe do an SBR job?.