New render crazing/cracking

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PS I know you've already answered but thought I'd take pics just incase any further comment. It doesnt sound hollow when you knock it (yet !!!!)

the dodgy light coloured bits were when i wet it after it started cracking and tried to re-float to cover the cracks - bad idea!!!!

Cheers
Sam

View media item 34689 View media item 34688
looks like you would have made a nice job of it if it hadent of cracked, because its only a small area i would take it off and start again
 
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sammoseley

thanks yes will do, sorry for one more question, I just used a splash of the waterproofer per spadefull of cement on the scratch, found it hard to work out the amount to use, maybe I didnt use enough. anyone got a simple rule, i'm gonna get a mixer for the next lot, mixing even that amount by hand in the barrow was a 'mare
and finally how much do you water down the SBR if your using it to kill suction on the blocks, if the answers read what it says on the bottle then fine :D
 
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thanks yes will do, sorry for one more question, I just used a splash of the waterproofer per spadefull of cement on the scratch, found it hard to work out the amount to use, maybe I didnt use enough. anyone got a simple rule, i'm gonna get a mixer for the next lot, mixing even that amount by hand in the barrow was a 'mare
and finally how much do you water down the SBR if your using it to kill suction on the blocks, if the answers read what it says on the bottle then fine :D

Measuring waterproofer accurately is crucial, because if you add too little, the job wont work out, and if you add too much, it affects the strength of the mortar,, (makes it go powdery).
The waterproofer i use all the time is "Evo-Plast Waterproofer". The measurement is simple,, 1 part Evo- plast, to 30 parts water,, as simple as that.
I have a plastic bucket with a line gouged into the plastic, which is my measure line for 30 parts/jugs water. I then use the jug to put in 1 part evo-plast waterproofer per bucketful. I can then fill up any water container/barrel accurately with the correct ratio, using my marked measuring bucket.
 
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Probably,, the wrong amount/too little waterproofer in the scratch coat, would have played a big part in the quick drying out of the top coat. Even though you gave the wall a good soak Sam, if you haven't put enough w/proofer in the scratch, the wall suction will soon dry out your top coat,,, plus the weather didn't help as the other guys have said.
Apart from it drying out too quick, you did a pretty good job of the render going by the looks of the pics, a nice even colour,, but as Micilin said the other week, if you go back over it and touch it up here and there, you change the colour,,, and you're right with what you said earlier,, useing a cement mixer gives the best results of all, and saves a lot of back breaking graft.

Here's another tip now you've got the w/proofer ratio sorted. :)
After you've scratch coated the wall (a day or two earlier) and it's now dried out and cured, ready for the top coat,, give it a soak down, then "let it drain off" for 5 to 10 minutes or so before you start putting on the top coat,, it's "not good", coating straight onto "soaking wet" scratch coat/lines.
 
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For the guys that render for a living.... does the weather ever get so hot/cold/windy etc that you wouldn't do a job, until it improved?

Sorry to hijack slightly OP
 
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For the guys that render for a living.... does the weather ever get so hot/cold/windy etc that you wouldn't do a job, until it improved?

Sorry to hijack slightly OP

If it was too hot, and a fair sized area, i wouldn't go for it. Most times, we'd wait for the sun to move off of the wall, then give it a wet down, then start, or do the walls out of the sun. It's what you get used too. It's not good if cement, plaster, concrete etc dries out too quick. I don't know how they get on in really hot countries. :confused:
Cold weather's not too bad, as long as it's dry, but freezing weather is a definite no. It's rare that the wind would stop you doing the job, unless it was on a safety issue, but it's worth remembering it can also dry out render etc quickly too. We used to roughcast with a crushed cockle shell, (Barra Shell). It was very light to use, and on a windy day, we had to spray/flick water on each wheelbarrow full before we cast/threw them onto the wall, because a strong wind would blow some of it away before it hit the wall, especially on an exposed gable end. Making it wet made it a little heavier. :)
 
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We used to roughcast with a crushed cockle shell, (Barra Shell). It was very light to use, and on a windy day, we had to spray/flick water on each wheelbarrow full before we cast/threw them onto the wall, because a strong wind would blow some of it away before it hit the wall :)

:D Barra shell!! Used it once on an extension.. on a windy day .. :eek: around 10 yrs ago, if i remember right we had a problem sourcing it.

Like you say rc....very light , and had to hit between gusts of wind :unsure:
 
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i used it once many years ago when the scaffold came down the scaffolder lost his footin and went face first down the wall luckily he got his balance again but his face was ripped to shreads he had about 40 stitches in one side of his face
 

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