Skimming over old patchy plaster

by Martyn Ingham
(Birmingham, UK)

Hi Paul.
I am about to skim a complete wall which is already covered with old plaster. There are quite large patches where I have had to scrape away the top coat, only, of the old plaster where it wasn't securely attached to the backing coat.

Should I fill in the patches first to bring them up to the level of the surrounting plaster and then skim the whole wall, or, will I be able to skim the whole wall straight off and handle the double thickness patches as and when I come to them.

I have done quite a bit of plastering in the past with quite good results but this is a situation that I haven't yet attempted.

Thanks for your advice. I have ordered your DVD and I'm really looking forward to watching it.



Comments for Skimming over old patchy plaster

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Oct 02, 2015
Skimming over old patchy plaster and dealing with small areas
by: Ben


Have the same issue here and understand that we would need to fill in the holes first however how long do we leave the wall once we've filled the hole before skimming the entire wall? Also should we use a different type of player for the whole from the skimming plaster?

Also, I have really small areas to plaster which I can't get my trowel into - what should I use instead to get the same finish?

Thanks in advance.



Hi Ben,

The best plaster to use for filling the holes is 'Bonding Coat' - it does what it says and sticks really well to a variety of surfaces, though if unsure you can apply PVA first.
Let the Bonding coat set - takes up to 2 hours, and then apply the skim coat - the best plaster for this is 'Multi-finish'. Both plasters are readily available at all DIY stores.

A variety of different trowels can be used for the smaller areas - such as a gauging trowel which is essentially a pointing trowel with a rounded end or a Midget trowel. Midget trowels are available from most tool suppliers) don't forget to wear it in - just like your normal trowel)


Apr 28, 2015
Making it easier
by: Paul

Hi Martyn,

Yes, definitely fill in the deeper areas first - so that it is all fairly flat before attempting to get it smooth.

Then apply PVA to whole wall to ensure that the suction is fairly similar throughout.

Hope it goes well.


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