Help with correct paint to use!

[sere890]

Hi all,

Really hope you can help on this!

I moved to a new flat in London 2 months ago, the walls in the hallways were painted in light yellow and there was so sign of condensation/wet patches on wall at all.

We then started to paint the walls in the hallways with a Dulux grey paint matt - Chic Shadow. and started noticing paint not drying in some patches. This went on for quite a few weeks.
We then went into a specialist paint shop and they recommended we used a paint stain blocker such as B.I.N Zinnser across the area as this should have hopefully sealed it and we could have painted over with paint matt again.

This sorted the problem initially but the darker slightly wet patches have now been coming back in the same area.

The previous owners did a damp treatment course in the flat and this wall was taken care of - this was roughly 2014 and it is currently under warranty.

We had the damp specialist coming round today to have a look and they advised that I painted the walls with the wrong type of paint, I should have never used the Dulux vinyl emulsion and definitely NOT the B.I.N Zinnser. They think it is not rising damp as in fact it doesn't rise too high, it could be a mix of condensation however they suggested that using a "breathable" paint would work.

Their advice was to strip off all the paint, and use a suitable "Non-vinyl moisture permeable emulsion paint"

Can someone please help on this? I have done some research and Dulux Trade Supermatt white
keeps coming up as a good one.

My question is - if I decide to start painting the area with this, do I need to do the whole wall in the hallway or can I just focus on the areas I want to cover? Would I then be able to use the original Dulux matt emulsion Chic Shadow on it? Or would this ruin everything?

I have seen that you can go to Dulux Decorator centres and actually get the Dulux Trade Supermatt mixed with the right colour....

THANK YOU SO MUCH IN ADVANCE!

S.

 

[Bonni]

You have a damp problem or condensation on cold walls.

 

[Ser90]

Thanks Bonni. I think you are right and it is a mix of both... what do you think I should do in terms of painting then?

Would a dehumidifier help at all?

 

[gc1967]

Yes it will bring the moisture out and allow you to paint but if the damp problem inst cured it will just come back sorry to say.

https://www.georgecoullpaintinganddecorating.co.uk

 

[conny]

I assume you are in a ground floor flat if the damp proof course was done in 2014?
If it's rising damp, (the damp company will not admit it is if they can get away with 'fooling' the client), my first thing would be to check outside for drill holes, (may have been plugged or filled with mortar) as evidence they drilled every brick along the course. The holes should be around 6" (150mm) above the outside ground level. Next check to see there is nothing bridging the course such as soil heaps etc If all seems well then I would consider that the internal wall plaster may be bridging the internal damp course and is only now beginning to show the effect. It may be that the plaster is bridging behind the skirting board and this would have to come off to enable inspection. If it is bridging then you need to chop it off with a cold chisel (bolster) and heavy hammer.
If you keep trying different paints you may just be throwing good money after bad hoping to solve the problem.

 

[misterhelpful]

Many people claim rising damp doesn't even exist, but I don't care what they say; if you've lived in a house with rising damp, you know it exists. I lived in a house until I was almost 20 that had rising damp and as soon as we got it treated, it went away. Over 20 years later, my mother still lives there and there is still no sign of any damp. It rarely rises higher than 50cm, but can rise to over 1m, in some circumstances (ours did). That said, it doesn't always mean that is what you have.

Many damp specialists are renowned for saying you have it, even when you don't, and just treating walls for it. They can also claim to have treated areas that they haven't (or genuinely just miss a wall) and then the damp shows its ugly head after a short while. This could be what has happened here or it could just be a condensation issue.
If there was moisture just in the corner, I would be more inclined to think it could be condensation, but the fact that it is effectively along the entire wall makes me think there is still likely to be some sort of damp issue.

Is that wall a fully internal wall or is it the inside of an exterior wall?
If interior, they may have not treated it at all and just hacked off the render and replastered. If exterior, as mentioned by conny, make sure there is no outside issue allowing moisture to bridge the dampcourse.

If the walls were only originally painted with a non-vinyl contract matt paint, such as the Supermatt you mention, then the issue you have will have been unnoticeable because that type of paint allows moisture to escape. Unfortunately, it is not at all hard-wearing and cannot really be wiped over in order to keep it clean.

As you have already effectively sealed the area with a vinyl paint, you will need to remove it if you want the Supermatt to be successful. Trying to blend just part of the wall in with it will be difficult, to put it mildly, and you will still probably end up with a different looking finish, even if it solves the wet looking patches issue.

Before you do anything, I would make sure of what the real cause is. That may mean paying for an independent damp inspection. Damp specialists will almost never admit their work has failed, so it doesn't surprise me that they have 'passed the buck'. What they have told you is technically correct, but if the damp has been treated properly, and you don't have lime mortar inside and out, there shouldn't be any reason to stop you using a vinyl emulsion.
Also bear in mind that you may have a minor leak, if there are any pipes somewhere near that wall, which could be slowly wicking moisture up the wall.