Render coming off

kelbal

Hi. I built a new pillar out the front of my house (I'm no builder, but throw my hand pretty well to most DIY tasks). Brickwork and angle beads all went up no bother, quite pleased with myself. I did a 4 to 1 sand\cement mix, and used Evoplast plasticiser\waterproofer in my water. I made the mix fairly workable, not too dry. I troweled it onto the faces of the pillar and did a fairly good job of making it smooth, working nicely to the beads. Was delighted with the job, all set to paint it to match the wall. Roll on a few days of drying later, and its cracking and coming away from the pillar :mad::mad:
Just wondering what I did wrong?
Thanks in advance

the_pen_turner

what kind of scud did you do ,
what mix for fist coat
how much lime in finish coat
what did you use to fix on the beads

kelbal

the_pen_turner wrote: »

what kind of scud did you do ,
what mix for fist coat
how much lime in finish coat
what did you use to fix on the beads

Think my inexperience is gonna come through now :eek:...
Scud? Whats that?
No first coat - threw it all up at once, about 10\15mm thick
No Lime
Beads were nailed into rawl plugs (roofing nails). They're on solid, no movement

the_pen_turner

kelbal wrote: »

Think my inexperience is gonna come through now :eek:...
Scud? Whats that?
No first coat - threw it all up at once, about 10\15mm thick
No Lime
Beads were nailed into rawl plugs (roofing nails). They're on solid, no movement

scud is watery cement sand mix and maybe sbr , it makes a key and helps everthing stick .

1st coat has no lime and is more for straightening everything out

you should have lime in top coat

kelbal

Thanks, I'll follow those steps on my 2nd try

tabby aspreme

Also wet the blockwork if it's very dry

Bonzo Delaney

All in the wetting in dry weather
Wet, scud, leave for a day or 2 to harden , wet , scratch coat, harden for a day, wet, finish coat leave for 2 weeks then paint if fully dry

Thespoofer

I think scud has also a small stone aggregate added (grit) that acts as a key/grip when plastering.