Dark marks on walls

[tdlf]

Hello!

I'm looking to buy a top floor flat, my concern is some dark marks on most of the walls (internal and external facing) and ceilings. The external facing walls seem to have marks that correspond to a dot and dab pattern and the internal ones are generally more broad and above radiators. The ceiling marks are more random and I would like to get into the loft to see if it is just where there is missing insulation.

It seems to be some form of ghosting but I'd really like to know if anyone has any other thoughts or ideas to fix it (insulating plasterboard, PVA, just paint it, lower the humidity etc)? I will also be at the property tomorrow if anyone has a good idea of what I can do to investigate.

Link to a yt video, check the description.
[youtube]aWpKhonwNc8[/youtube]

Thanks in advance for any help!

[dewaltdisney]

I cannot get the video but from what you have said these are dirt smut marks formed by the heat differentials in the room. Generally, regular decorating keeps the walls clean but this ghost imaging is the slow buildup of air-borne dust, dirt, and soot particles on walls formed by slightly colder areas where the heat does not penetrate uniformly. Hence the ghost imaging of dots and dabs, mortar lines, and studs. A good hoover over and a paint job covers it, do not wash or put PVA on the walls it will mess them up.

DWD

[tdlf]

from what you have said these are dirt smut marks formed by the heat differentials in the room. Generally, regular decorating keeps the walls clean but this ghost imaging is the slow buildup of air-borne dust, dirt, and soot particles on walls formed by slightly colder areas where the heat does not penetrate uniformly. Hence the ghost imaging of dots and dabs, mortar lines, and studs. A good hoover over and a paint job covers it, do not wash or put PVA on the walls it will mess them up.

DWD

Thanks very much DWD. My concern is that I do not know the rate at which it will reappear if we repaint or if it there's that heat differential because it's not very well insulated (harder to fix in a leasehold flat). Also doesn't explain the interior walls as well.

I didn't mention that it's a 1980s build and has been uninhabited for 3 months, not sure when it was last decorated and generally poor order, so it does give credit to your hoover and paint idea.

I cannot get the video

Try going to youtube and putting /watch?v=aWpKhonwNc8

[dewaltdisney]

Okay, seen it now. I would say that it is neglect more than a damp or insulation issue. You can often see the dust stain marks above radiators and lights. These slightly warmer and colder areas cause an thermo electrostatic charge that grabs the dust and crap in the air and over time it builds up causing stains. From what I see there are no classic damp stains that would indicate a water ingress issue. Flats, by their nature, have a lot of moist air from baths, showers and cooking and this tends to exacerbate the wall marking. Good ventilation when possible, keep the decor smart and this should be okay. Younger folk tend not to have heard of flannels which you wipe most of the water off yourself after a shower to minimise the dampness of the towels. Drying towels are a big source of damp vapour. My son's house has always got damp towels, he never listened.

DWD

[tdlf]

Thanks very much for your help! Certainly sounds like a neglect/humidity issue then, I would still be interested to hear if anyone else has experienced and successfully remedied it by changing habits, or if it did reappear how long we can expect it to last after redecorating.

[dewaltdisney]

I think that you have it in your head you will be painting every year but I very much doubt that is the case. Now you know the cause and if you minimise the airborne, dust, moisture and especially avoid smoking or bloody candles everwhere that women love, it will fall into a normal redecoration cycle. I suspect the flat has not been touched since being built the 3 month empty period probably did not help and their may have been tenants who did nothing to keep it nice.

There are paint products that can be used to prime and seal the surface such as Zinsser Gardz see the video for guidance https://www.youtube.com/watch?v=dR_743ud8hE Using a roller it goes on quickly and easily. This will seal the surfaces prior to normal emulsion painting and may give you the reassurance you want. When you paint get a decent trade paint not the pissy stuff from BnQ.

DWD