DIY Render on block

Members online

Status
Not open for further replies.

Robstephens

New Member
I've got a sound scratch coat up on my garden shed, it's hardened off nicely (10 days) Yesterday I started on the top coat and hit a problem, in places along the bell it's slumped and is really soft.
I have used bondit 3-1 and tried to use only just enough water to get a stiff mix but it's still slumping.

What are the problems using 3-1, have I over mixed or got too much 3-1 in the mix? It's strange that its only appearing on sections of the wall not along the whole.

I have been careful and gauged everything into the mixer 4-1 scratch, 5-1 finish and more waterproofer in the finish than in the scratch

Any ideas?
Rob
 

goody

Private Member
As above, same thickness needed all over so bell needs dubbing first if you're gonna put one on.
 

Rhys

Well-Known Member
Sounds like too much waterproofer. If there's waterproofer in the scratch coat and the top coat there's nowhere for the water to go except down. Surprised it hasn't slid off tbh. That and what's already been said.
 

Fatarm

Trainee mod
I've got a sound scratch coat up on my garden shed, it's hardened off nicely (10 days) Yesterday I started on the top coat and hit a problem, in places along the bell it's slumped and is really soft.
I
have used bondit 3-1
and tried to use only just enough water to get a stiff mix but it's still slumping.

What are the problems using 3-1, have I over mixed or got too much 3-1 in the mix? It's strange that its only appearing on sections of the wall not along the whole.

I have been careful and gauged everything into the mixer 4-1 scratch, 5-1 finish and more waterproofer in the finish than in the scratch

Any ideas?
Rob

What's bond it 3-1?
 

Fatarm

Trainee mod
Cheers nisus, Never heard of that make of waterproofer, you know what I was thinkin tho?? Thistle bond it! Oops:RpS_thumbup:
 

Robstephens

New Member
Cheers for the comments guys, Makes sense about the waterproofer, got reasonable suction most everywhere except the troublesome areas.
I scrapped off about 1/2 sq m and reapplied a much drier mix, still struggling and it looks like its going to stay put.
Yes I dubbed out the bell on scratch but with zero suction the inevitable happened.

There will be no repeat, next time I'm going to leave it to you guys who no what they are doing. 18sq m, a Ton of sand, 2 lost weekends, a sore arm and a result that may / may not be what I was hoping for!
You live and learn.
 

beddy

Well-Known Member
no need for waterrpoofer in topcoat. only scratch. just put the some lime in the topcoat to the same ratio of cement.
 

pwi

Member
Fair play for having a go , but as you say you live and learn , get the guys in that know what they are doing .
 
Status
Not open for further replies.
Top