PLASTER CRACKING -MORE THAN A HAIRLINE?

[sexyswampthing]

I HAVE HAD MY WHOLE HOUSE(1940) REPLATERED OVER 8 WEEKS AGO.BACK TO THE BRICK-SAND/CEMENT-SKIM-WATERED DOWN SUPERMATT 70/30-50/50-PURE SUPERMATX2 COATS. THE HOUSE IS A SHELL (NO SKIRING BOARDS,RADIATORS,CENTRAL HEATING,NOTHING TO INTERFERE)WE ALLOWED THE PLASTER 4 WEEKS TO DRY OUT AND HAVENT EVEN STARTED ON SOME OF THE ROOMS YET.WE LEFT A WINDOW OR TWO OPEN OVER NIGHT AND HAVE NOT USED ANYTHING ELSE TO DRY THE PLATER.SMALL HAIRLINE CRACKS HAVE APPEARED EVERYWHERE THEY SEEM TO BRANCH OFF IN NO PARTICULAR ORDER BUT ARE ALL OVER THE WALLS.THE CRACKS ARE GETTING SLIGHTLY BIGGER.I HAVE REMOVED THE SKIM AND THE CRACK IS ALSO IN THE ROUGH COAT.I HAVE SPOKEN TO MY PLATERER WHO SEEMS HELPFUL BUT HAS SUGGESTED IT MAY HAVE HAPPENED AS WE LEFT ONE WINDOW OPEN(THIS IS DONT BELIEVE). WHEN THE PLASTER WAS FIRST PUT ON IT DRIED VERY QUICKLY AND MY FATHER SUGGESTED THE PALSTER HAS 'PUT IT ON TOO TIGHT'.I WOULD LIKE TO KNOW HOW TO REPAIR THIS-TAKE IT ALL OFF BACK TO THE BRICK AND START AGAIN-OR FILL THE HUNDREDS OFF CRACKS?(IS THIS NOT JUST HIDING THE PROBLEM AS WE PAID A FEW QUID TO GET THE WHOLE HOUSE DONE-THANKS

 

[joe-90]

WE PAID A FEW QUID TO GET THE WHOLE HOUSE DONE-THANKS

Well if it was only a few quid then take it all off and start again.

 

[PrenticeBoyofDerry]

Sounds like there has been either lot of suction or the mixes have been too dry, these could lead to both your base coat and top coats dry too fast and at different rates.
This will force the coats to shrink and crack.
What condition were the bare brick walls in?
Were they dry and dusty?
It would be ridiculous to blame it on one window being open, or many windows being left open or them all being shut!
Sounds like either bad prep or bad mixes.
Get the man back to sort it out.
If lots of cracks but surface still solid and sound, might be worth a total re-skim.
If just odd crack here and there, easi-fill and sand down.

 

[sexyswampthing]

thanks for your reply PrenticeBoyofDerry. I believe the bricks were dry and dusty-I have kept a few walls bear brick as a feautre and cleaned them up fine.I dont think theres a problem with the bricks but im no expert.He is coming out today I just wanted a heads up. If he deos skim over the old cracks(as there are too many to fill) is that not just hiding the problem-if the rough coat is cracking will it fall off in time?

 

[NickB_99]

If he deos skim over the old cracks(as there are too many to fill) is that not just hiding the problem-if the rough coat is cracking will it fall off in time?

If lots of cracks but surface still solid and sound, might be worth a total re-skim.

As PBOD says, so long as the base render is ok and the wall is basically sound, then a reskim will be fine. (think you said it was render, not plaster underneath).
Try testing the walls by tapping in different places with a knuckle. If you get a hollow sound in some areas and some more solid sounding bits, then the base render is probably suspect too. If this is the case then you are right, it would be hiding the problem with only a reskim.
If it all sounds solid, then the re-skim should be fine.

 

[Richard C]

If the cracks are also through the render base, possible causes;
• He’s come a cropper with suction & the didn’t damp the brick/block down enough
• Render coats were too strong or only one applied too thickly; there should be two adding up to roughly 10-12mm thickness, the second coat should be slightly weaker than the first.
• How long did he leave the base before skimming? If he let it dry out did he damp down again?

If the skim is blown (sounds hollow & comes away from the render easily) it will all have to come off as will the render base if that’s suspect. If the render base is sound, the cracks will still have to be tapped or they will almost certainly show through the re-skim again. If the bricks/blocks were cracked & he just rendered over the top, no amount of tape will hold it together, cracks like that need much more radical remedial work.

He’s talking crap about leaving the window open which makes me wonder if he actually knows what he’s doing or is just trying to “snow” you to get out of it.

 

[sexyswampthing]

he did apply two rough coats and let it dry but i dont think he damped down.The platerer has been round today and had make all the cracks bigger and filled them.He is going to leave it a week and see if any more cracks appear.If no cracks appear then he will skim-if cracks appear then its all coming off.Hes accepting responsability so hopefully we can resolve
thanks for your help

 

[PrenticeBoyofDerry]

Sounds like a fair resolution, a bit inconvenient but at least he's put his hand up.
Glad to hear you got it sorted in a dignified way.

 

[stevethespreader]

he used sand and cement as a base coat and never watered the walls down? and the whole house was done like that? and now its cracked because its dried out to quickly thats not good news i would be tempted take the whole lot off and start again room by room while the house is just a shell before any fixings go in, the whole house though blimey i wouldent let him back in if i were you

 

[Richard C]

As PBD, at least he’s held his hands up & taken responsibility but I’ve got to say I’m thinking along the lines of Steve. If he’s got the render mix too strong or not damped down enough (like using a hose spray!) before laying up the render that’s a very basic mistake to make & I would be concerned about the render being stable enough to hold the skim in the long term. He seems to be doing it right & he may have been caught out (as we all have at some time) but I would be asking some questions about how much experience he has!

 

[joe-90]

I can't see him taking the lot off and paying for new materials.

 

[sexyswampthing]

TO BE FAIR HE MAY HAVE DAMPED DOWN AS I LEFT HIM TO IT-I ONLY POPPED IN AN OUT AS WAS IN THE GARDEN MOST OF THE TIME. MYSELF AND FRIENDS HAVE HAD WORK DONE BY HIM BEOFRE AND IT HAS BEEN SPOT ON-THATS OVER THE PAST 5 YEARS.WHEN HE CAME YESTERDAY HE WAS GUTTED AND ASSURED ME THE WALLS WILL BE PERFECT AS HES A MAN OF HIS WORD.FINGERS CROSSED FILLING AND SKIMMING WORKS-IF NOT LOOKS LIKE ITS ALL COMING OFF

 

[joe-90]

Switch your caps lock off ffs.

Just tap it. If it sounds hollow it has to come off.

 

[headworx]

Switch your caps lock off ffs.

Just tap it. If it sounds hollow it has to come off.

I've just tapped my caps lock key too and that sounds hollow...Looks like its gotta come off too

 

[sexyswampthing]

Plaster has cracked even more after filling and leaving for a week. The plasterer has offered to take it all off and dot an dab it.Im not happy with this as this as I have been lead t believe this is the 'cheap and nasty way(thats why i paid for a proper job). Plaster will render if we wish but then cant guarentee it wont crack(Now he tells me!)We have limited options as cash in hand job. Advise please form you professionals. Tell me if im old school
Thanks