Why has my Polyfilla cracked ??

[BeerBoy]

I had to repair a section of my plastered wall after removing some tiles. The area in question was about 100cm by 50 cm and about 1cm deep - it, goes down to the brickwork. Anyway, I bought some plaster repair powder, mixed it up and repaired the hole. Only problem is, as it dried it started to crack and now looks like some sort of African river bed where it hasn't rained for about 10 years. What did I do wrong ? Did I choose the wrong product ? Was the hole too deep ? was the consistancy too dry or too wet ? Also, what should I do to fix it ? Remove it all and start again ? Add normal polyfilla to fill the cracks ?

[The Natural Philosopher]

Hole too deep.

Reskim with poly skim etc.

Always use bonding plaster for big holes - its loaded with non shrinking filler.

[stuart noble]

Yes

[Dave Liquorice]

"Plaster repair powder" sounds like the right stuff what do the instructions say it's suitable for?

1cm is quick thick to do in one pass.

Possibly to wet, I think this is mistake many people make, if it slumps at all it's too wet.

Is the surface now flush or proud? If so you'll need to take it back a bit then open out the cracks and skim. I'd use the same stuff as you have it...

[BeerBoy]

Do you mean I don't have to rip out what I've already done ?