spots on plaster

[lisaanddave]

Hi Everyone,

We have just had our ceiling skimmed with plaster by a professional not ourselves! It was a sort of popcorn artexing effect before. We are very pleased with the nice smooth finish, however we have now been left with groups of spots , smooth but discoloured to the rest of the plaster. Bit like a leopard print effect in certain areas all over the ceiling but smooth.

It is getting better with every coat of paint we do ( now up to our 3rd/4th coat of ONE COAT!) I was just wondering does anyone know what they are, what causes it and will it eventually go if we keep painting it??

Any help would be greatly appreciated.

Thanks

Lisa

 

[noseall]

It is probably exposed minerals in the artex showing through.

There are stain block/barrier primers available to counter this.

Try this.

 

[roughcaster]

Sometimes,, a skimmed wall/ceiling may have small areas of blisters in the finishing plaster, that have gone off/set before the plasterer could trowel them out. When that happens, the plasterer would then have to go over the blisters again (with effort) to trowel them flat. These former blistered areas would then look "spotty", but would also have become "over polished" and shiney, making it harder for the paint to build up in those areas. It will all cover in the end, but make sure each coat of paint dries out, before you put on the next one,, or try Noseall's suggestion with the blocker.

Roughcaster.