Painting over Supermatt

[aardvarkdave]

Our 6-yr old house is (I think - we're not the 1st owner) painted with supermatt. It's certainly got the supermatt properties - i.e. very matt finish, washes off with a sponge!

I'm redecorating (with dulux trade diamond matt emulsion which is a little runnier than the normal vinyl matt) but painting the supermatt is like painting a sponge. So... how much should I be thinning the emulsion for painting onto Supermatt? I don't want to store up problems for the future so I'd rather do it right once than have to redo it in a couple of years.

Thanks,

Dave

PS Thanks to everyone for all the advice on this forum - its been incredibly helpful so far. One interesting thing is that I've had none of the problems mentioned on here with flashing/lifting etc. with the diamond matt emulsion - maybe its been reformulated. If anything, I find it goes on better than the normal emulsion.

 

[54aardvark]

I'd mist-coat, recently had a couple of extra-dry walls, the first was a nightmare, even had to sand off some of the roller marks it was drying so quickly - came up OK eventually. Second one, noticed how quickly water was being absorbed while washing down and put on a mist-coat - nae probs.

 

[aardvarkdave]

Thanks for that - did you go all the way to 50:50 dilution for your mist coat onto supermatt, or something a little less liquid?

 

[54aardvark]

Normally a mist coat is 25-30% water. Some emulsions are thicker than others, you want it more single cream than double cream, but get it fairly sloppy.

Generally in the trade, we'll use a non-vinyl contract matt for mist coating, its just sealing the wall so it doesn't need to look great at that stage. Also the contract matt is far cheaper - no point using the expensive stuff for misting. Quite often clients will say " I've got the paint" (ie they've had a bargain in FADS!) and I'll swap their c***p paint for something decent (which will take 2 coats rather than 3-4!) and use their stuff for mist-coating on other jobs.

 

[aardvarkdave]

Thanks for the advice - I experimented a bit and found 10% dilution (about single cream as you suggested) was enough to keep a wet edge and moved the drying time from c.5mins to about 30 mins, easily long enough to work on it.

Cheers for the help
Dave