New plaster

[idiots]

Hi guys,

I hope you can help me,

I have just plastered my kitchen/Diner after striping it back to bare brickwork i have used multifinish plaster and have used pva before and after each coat but there are a couple of places that sound blown (hollow when you tap it) any advice is welcome.

 

[markwm]

Did you bond it first? ie, bonding coat, hard coat, sand and cement?

 

[idiots]

yes and i keyed each coat, Also there is no central heating in the room so i dont think it has dried out to quickly

 

[roy c]

What backing coat did you use on the brick-work? and Go thru the process of how you skimmed it, then maybe we will get an idea of where you went wrong>

 

[idiots]

First i used pva then i used thistle bonding coat (purple bag) then multifinish (orange bag)

 

[Richard C]

Is the wall brick as in proper brick, or is it blockwork?

 

[idiots]

Yes it's the wall to the adjoining house (Proper Brick)

 

[Richard C]

OK, it’s a relatively low suction background so Bonding was a good choice; it’s supposed to take thickness of around 10mm or so but it can still play up, especially if your laying it on thick; did it start to craze as it was going off? I always keep my eye on it, add water & work the surface (sometimes a lot) as necessary if it starts to show any signs of crazing, if you don’t, it will end up looking like the puff pastry on one of “Tosco’s Finest” steak & ale pies; but they are nice!

If there were no visible signs of over suction on the base coat & it looked & sounded OK before skimming, it’s got to be down to poor adhesion. If it’s only in certain areas I can only think its due something on the face of the bricks; I would say it's got to be a problem with the base coat but it’s rather difficult to diagnose over the internet!

 

[idiots]

No there was no crazing throughout and i did use water as it was going off to smooth it out, As there are only two patches about 1m sq would you recommend striping it back and replastering it

 

[Richard C]

No there was no crazing throughout and i did use water as it was going off to smooth it out, As there are only two patches about 1m sq would you recommend striping it back and replastering it

If it sounds hollow & has obviously delaminated then yes, I would hack it off & start again. But you must try & establish why it happened; something on the substrate, different bricks, poor preparation or whatever, if you don’t understand & cure the cause of the problem, you stand a good chance of repeating it!

 

[idiots]

Ok thanks for all your advice Richard c,
I think i will hack it off and have a look at the bricks to try and see if there is anything on the surface, Once again thanks for your help & if i find out what it is i will let you know

 

[idiots]

Hi Richard c i have found the problem, I hacked off the plaster and found that there was still some old plaster underneath and it was this that had blown thus making my new plaster no good ( i've looked at some before photo's and i found 1 more patch with the same problem) so it's my bad A lesson learnt thanks for all your help anyway.

 

[Richard C]

Hi Richard c i have found the problem, I hacked off the plaster and found that there was still some old plaster underneath and it was this that had blown thus making my new plaster no good ( i've looked at some before photo's and i found 1 more patch with the same problem) so it's my bad A lesson learnt thanks for all your help anyway.

Nice to get some feedback, thanks for making the effort.