Paint going on weird...

nagero

Hi

When we bought our house it was painted magnolia internally. Some of the walls have an uneven appearance to the paint. Kindof like a map.

The raised portions seem to take new paint fine but the paint comes out darker on the rest.

At this stage we're considering stripping back to the blocks and getting it re plastered. Is that the best course of action or would just skimming it again do the job?

Also is there much difference (cost wise) to skimming over existing plaster or bare blocks?

thanks

kevin

plasto

nagero wrote:

Hi

When we bought our house it was painted magnolia internally. Some of the walls have an uneven appearance to the paint. Kindof like a map.

The raised portions seem to take new paint fine but the paint comes out darker on the rest.

At this stage we're considering stripping back to the blocks and getting it re plastered. Is that the best course of action or would just skimming it again do the job?

Also is there much difference (cost wise) to skimming over existing plaster or bare blocks?

thanks

kevin

You wont need to strip it all off. There is a product called 'Thistle Bond-it' that you roll-on like paint, leave to dry for 24hrs, then skim over.

I use it all the time, saves alot of time, mess and money!!

PM me for more info.

simon

secman

We are just coming to the end of a dormer new build and in the the downstairs of the house all "internal walls were sand , cement and plastered, whereas all "external walls " were dry lined.
When we painted the walls we noticed that on the sand and cemented ones, we got this mapping effect. From other posts on this subject we were advised that this is due to a reaction with the lime content in the render and the paint. So should you get the walls re plastered , it can happen again !
The solution apparently is to lightly sand the effected areas and then paint over using a brush, as a roller only magnifies the problem. As of now we have not takled it yet ,but when we do , shortly thats what we will be doing. I tried it on a small area and it seems to work.

Best of luck
Secman

Wertz

Mapping is a c*nt, no other word for it.

Since you've the walls painted already, It's going to be hard to tackle the underlying cause....so I would suggest getting some sort of primer/sealer like the types Zinsser or Sherwin-Williams produce. These are white shellac paints in differing solvent bases (alcohol, oil and water base). When applied they form a vapour barrier and seal everything on the surface, allowing you to paint your emulsion coats on without worrying about damp, mildew or the dreaded mapping showing through. I find the alcohol-based one the best in terms of drying, adhesion and stain blocking power.
These primers are relatively expensive (about ~20 euro a litre) but compared with the cost of re-skimming and then re-painting, it might be a better option.
You can get these primers tinted to some extent so as to form a better colour base for the finish colour. They are a bit messier than paint to work with (more splashes and drips) and clean-up can be difficult so make sure all surfaces not to be coated are covered/masked/removed.

Not looking to do plasto out of a day's crust, but IMO re-skimming is OTT. I've left plenty of houses looking top notch that had mapping problems. If plasterers would use bonding instead of scratchcoat sand and cement, there wouldn't be half these problems in new builds. You rarely if ever see it happening in older houses.