Hairline Cracks

[bobbybilly]

Good evening Gentlemen

Got a bit of a problem which you may help me with.
Ok I'm not a plasterer but I'm not bad. Slow as sh-t but all the stuff I have done is flat as a Kippers di-k.

Dot and Dabbed my living room (6x 4 Metres) before Xmas and skimmed it in January

Had a nightmare skimming as all the boards sucked like Monica Lewinski. I had give them a pva at 5to1 just to help me.

Used Extratime because as I said I'm slow and 64 with a effed wrist..

All eventually came out fine even with my OCD.

Had one joint crack but that was my fault because I didn't put enough on the joint.

All the wall were misted with Dulux Supermatt

Anyway today I have looked at the walls and have several hairline cracks that weren't there yesterday

Some are on joints but a couple are on the middle of boards. House is 1930's.

Any ideas or have I just effed up. Never had this before

 

[bobbybilly]

Afternoon All

Been thinking about the cracking and after reading a thousand posts about skim cracking I'm none the wiser..

The walls were dot and dabbed with Siniat 12.5mm boards using GTEC adhesive.
All joints taped with Gyproc Extreme
Boards 2 coated with Multi Finish
Flattened both coats with a Speedskim
The first coat may have been a little dryer than I'd like before 2nd coat was applied.
The cracks are mainly on joints even where there is a dab
There is also a few cracks in the middle of boards
Skim has been on for about 3 months.
There were no cracks before I mist coated it.

The only reason I can think of is the skim has finally dried out and has shrunk causing the cracks.
I'll vee out one of the cracks and fill with Toupret or Easifill and see if it cracks again.

Any ideas? The wife wants Little Greene painted and at £110 for 5 Litres I don't want to chance it cracking

I'm going back to float and set for the Hall stairs and landing

 

[Stewie03]

How generous was you with the dabbing

 

[FreeD]

Afternoon All

Been thinking about the cracking and after reading a thousand posts about skim cracking I'm none the wiser..

The walls were dot and dabbed with Siniat 12.5mm boards using GTEC adhesive.
All joints taped with Gyproc Extreme
Boards 2 coated with Multi Finish
Flattened both coats with a Speedskim
The first coat may have been a little dryer than I'd like before 2nd coat was applied.
The cracks are mainly on joints even where there is a dab
There is also a few cracks in the middle of boards
Skim has been on for about 3 months.
There were no cracks before I mist coated it.

The only reason I can think of is the skim has finally dried out and has shrunk causing the cracks.
I'll vee out one of the cracks and fill with Toupret or Easifill and see if it cracks again.

Any ideas? The wife wants Little Greene painted and at £110 for 5 Litres I don't want to chance it cracking

I'm going back to float and set for the Hall stairs and landing

Can you make a feature out of the cracks? Like a giant cobweb mural?

 

[Cockney]

Afternoon All

Been thinking about the cracking and after reading a thousand posts about skim cracking I'm none the wiser..

The walls were dot and dabbed with Siniat 12.5mm boards using GTEC adhesive.
All joints taped with Gyproc Extreme
Boards 2 coated with Multi Finish
Flattened both coats with a Speedskim
The first coat may have been a little dryer than I'd like before 2nd coat was applied.
The cracks are mainly on joints even where there is a dab
There is also a few cracks in the middle of boards
Skim has been on for about 3 months.
There were no cracks before I mist coated it.

The only reason I can think of is the skim has finally dried out and has shrunk causing the cracks.
I'll vee out one of the cracks and fill with Toupret or Easifill and see if it cracks again.

Any ideas? The wife wants Little Greene painted and at £110 for 5 Litres I don't want to chance it cracking

I'm going back to float and set for the Hall stairs and landing

How long was the first coat of multi on before second was applied?
Was the second coat fresh gear?
How much adhesive was used per board?

I’ve never seen cracking mid board on d&d before.

 

[bobbybilly]

How long was the first coat of multi on before second was applied?
Was the second coat fresh gear?
How much adhesive was used per board?

I’ve never seen cracking mid board on d&d before.

Second coat was applied about 45 minutes after the first. It had Extratime in the 1st coat so was wet.

Yes the 2nd coat was fresh mix

The Multi was well in date

4 columns of dab per board about 12 inches apart vertically solid bed around the perimeter of the walls

"

I’ve never seen cracking mid board d&d before.

Neither have I!!!!

Thinking of taping the cracks and reskimming the 2 affected walls.
what's best over dulux Trade Supermatt. PVA, SBR or I have a tub of Cementone Plastering Stabilser(Green grit).
Probably drill a few holes and squirt a bit of Adhesive foam in the bits which have cracked.
The wife will kill me as she wants it painting this week but i'm not blowing 250 quid on paint for it to crack again.

 

[SpeedskimSF]

Sounds like old plaster boards to me even with PVA if the moisture is gone from the boards , as in they have been slabbed for a while and heating has been on etc etc .
If they sucked in when you were coating they will have sucked in the wall adhesive too so maybe that didn't get a 100% hold so when your troweling up your moving the boards even just 1mm will eventually become 2-3 with shrinkage.
Drill and plug the wall with stainless mushrooms SBR the wall and go again .

 

[bobbybilly]

Sounds like old plaster boards to me even with PVA if the moisture is gone from the boards , as in they have been slabbed for a while and heating has been on etc etc .
If they sucked in when you were coating they will have sucked in the wall adhesive too so maybe that didn't get a 100% hold so when your troweling up your moving the boards even just 1mm will eventually become 2-3 with shrinkage.
Drill and plug the wall with stainless mushrooms SBR the wall and go again .

Hi Mate
That's what has probably happened. Just had a look at some pictures and the boards where delivered on the 22nd of November and dabbed up on the 14 December. Then as Xmas was coming i tidied up the room and there was a fan heater on as there was not Rads on the walls. I didn't skim it until 14th of Jan. I pva'ed the boards because I thought they may be a bit dry, should have put a coat of SBR on before I skimmed.
All the smaller walls are fine it's just the 2 big walls that I struggled with that have cracks. All the cracks are where there is no adhesive underneath. that's why I wondered if squirting some foam in would help to stabilize the boards.
Do you think I should give the boards a thinned coat of SBR then a neat coat and skim when tacky?

Thanks for your help.

 

[SpeedskimSF]

Personally id go neat its not the thickest of material anyways lash 2 coats on crack on it will be all good but consider the dry wall mushrooms mate if there is movement SBR wont fix this .. your aim is to pull the slabs back and sit on the dots you placed there originally ,
Regarding expanding foam if you're going to use. this try low expansion I learned the hard way with this. similar situation came back on site the morning after with reveals bulging probably 1/2 an inch more than they should.