cracks in new render

[tiger]

Just had an exterior wall rendered with 4-1-1 scratchcoat with waterproofer and
5-1-1 topcoat one day on and i`ve noticed some small hairline cracks and some other very slight spider webb type cracking. Any suggestions on the possible cause and remedy please.:-0

 

[nickelarse]

whats it on?

 

[tiger]

rendered onto exterior brick wall

 

[nickelarse]

possibly didnt leave the scratch long enough. drying too quick can cause it

 

[tiger]

the scratch coat was left on for 3 days

 

[hollybank]

Did you wet the wall down first???

 

[tiger]

Did you wet the wall down first???

Yes they did wet the wall down well, it did seem to suck up the lime in the mix they said and more water was added as they went along no added plasticiser was used though. I was also wondering if it was likely more cracks would appear as time goes on and could they get bigger?

 

[craigw]

don't put lime in your 1st coat,it will cause the top to suck like ****.
why oh why are people putting lime in their 1st coat. i have rendered/dashed hundreds of houses in 26y's of doing this great job :-0:RpS_lol:,never had a crack appear,also 4x1 seems a tad weak,and with lime would make it weaker,i always got taught to scratch 3x1,on stone or brick or block,at collage and by my old boss,who had been plastering 40ys + when i was 16.

also what sort of sand did they use,if its a soft river or building,hairline cracks would appear,it don't bind well enough.:RpS_thumbup:

 

[tiger]

only the top coat had lime, the sand was plastering sand from wicks, seems to be a good grade, but what do I know.

 

[craigw]

only the top coat had lime, the sand was plastering sand from wicks, seems to be a good grade, but what do I know.

bugger:RpS_drool:,i read it as 4-1-1,meaning 4 sand 1 cement 1 lime:RpS_blushing:

i shall not rant again:RpS_biggrin:

 

[lctanner]

bugger:RpS_drool:,i read it as 4-1-1,meaning 4 sand 1 cement 1 lime:

so did I.......whatis it ten?

 

[stevebell]

would the cracks appear from over rubbing with a sponge

 

[Blade]

a lot of the time the very fine hairline cracks will be lost when painted , if there bigger than hairlline i could be all sorts of reasons . not keen on wickes sand personally . Its harsh to blame the plasterer when there is fine cracks .

 

[superspread]

are you sure it was brickwork and not thermalite blocks.

 

[Dirtybill]

I had this problem with Jewsons sand with snowcrete through it

 

[lucius]

Have you ever put stabiliser on a rendered wall before painting that shows all the hairline cracks you couldnt see before