Surfactant leaching

[coletteh]

We are hoping to paint the interior walls of our office with Farrow & Ball (either Estate or Modern - not sure yet). Currently, the walls are painted in what I assume is vinyl silk paint - so it's got a glossy finish without actually being a gloss paint. The problem is that there appears to be what I think is surfactant leaching - there is a brown oily exudate oozing here and there on the walls, and some internet searching suggests that this is surfactant leaching, possibly due to the room being cold and prone to condensation.

Once we have made our alterations, the room will no longer be cold or prone to condensation, so that's one problem sorted. We also plan to wipe away the surfactant leaching and then sugar-soap the walls to remove all traces of grease.

However, will this be enough to stop the same thing happening and then ruining my lovely new F&B finish? Or are we safer to simply plasterboard over the offending wall and then paint that in F&B instead?

Thanks

 

[JohnD]

brown stuff you say?

is it near a chimney? Or a chip frier?

or was there a formerly heavy smoker in the house?

is this on an outside wall, or in internal walls too?

what is on the other side of the wall? Any pipes or damp patches?

photo would be nice.

 

[coletteh]

As far as I know, there has been no smoking in the house for the past ten years. It is indeed near a chimney and it occurs only on the one exterior wall in the room. It is in an attic conversion of a 300-year-old stone-built property. There is currently no heating in there, but there will be a central heating radiator put in there before we decorate. There are two reasonably well-sealed Velux windows. The loft insulation in the attics to the side is reasonable but not great - we are going to make it thicker before decorating. As far as I know there are no pipes near it. Re damp patches, there are a few kind of tide marks on the walls, but these don't look too scary and in fact I think they are simply where it is so cold in the room that water vapour has condensed on the walls a dribbled down. Certainly doesn't look like mould or rising damp.

No photos at the mo - sorry.

Thanks for any further help.

 

[JohnD]

It is indeed near a chimney and it occurs only on the one exterior wall in the room.

then perhaps it is tarry deposits soaking through the wall. See if this makes sense. If so, they will continue unless you have a barrier to stop them.

Once you are sure of the cause, someone will know what to do about it (not me)

p.s. a disused chimney needs to be ventilated top and bottom, or it will become damp

 

[Zampa]

Saponification also presents itself in this way...im wondering if the eixisting coats was an oil based applied over a plaster or rendered wall that hadnt been sealed with alkali resisting primer..long shot but as we dont know anymore at the moment you never know

Good case for bleeding from a chimney though