What causes these black marks?

kelbal

Hi,
Please have a look at my pictures below, this staining is in 2 of my upstairs bedrooms, and the upper part of my landing (that meets the attic). I've painted over it but it keeps coming back. I'm wondering what the cause is. I had been thinking that it was due to moisture from drying clothes on radiators but its not consistent across all rooms - I don't put properly wet clothes on them, just finish them off.
I'm also wondering is it to do with insulation in the attic. I redid the insulation a few years ago - I'm wondering did I maybe stuff it too much into the eaves, not allowing breathing and hence moisture build up?
Anyone experienced this kind of staining before?
Thanks

Satriale

Looks like mould to me, is the ceiling in those pictures joining external walls?

Outkast_IRE

When you did the attic insulation, did you ensure that the insulation was above these parts of the room, but also that it did not block ventilation from the eaves of the roof ?

If you blocked the ventilation in the attic then that would be the first thing to sort.

Are you sure the insulation is above these parts of the ceiling ?

After that, stop drying clothes altogether indoors, its a terrible practice and just drives moisture into everything else in the house.

Also is there dedicated ventilation in these rooms ?

kelbal

Outkast_IRE wrote: »

When you did the attic insulation, did you ensure that the insulation was above these parts of the room, but also that it did not block ventilation from the eaves of the roof ?

If you blocked the ventilation in the attic then that would be the first thing to sort.

Are you sure the insulation is above these parts of the ceiling ?

Also is there dedicated ventilation in these rooms ?

Will check the insulation. No dedicated ventilation in the rooms, as in a vent in the walls, there's small ventilation slots in the windows though.
thanks

kelbal

Satriale wrote: »

Looks like mould to me, is the ceiling in those pictures joining external walls?

yes - the ceiling in the relevant spots is at external walls

lillian770

It does look like mould to me as well. Normally it is associated with poor ventilation and moisture build up.

Satriale

kelbal wrote: »

yes - the ceiling in the relevant spots is at external walls

I had these marks but only on external walls, i killed off the mould with bleach and repainted, i also repositioned the insulation above to make sure it was covering the plasterboards properly at the edges, (but make sure not to block any ventilation to the roofspace as Outcast points out) It returned in a few small spots and i've bought a mould additive to add to the paint to see if i can finish it off altogether(i will be bleaching it again first though as that seemed effective)

Outkast_IRE

Once you check the insulation, and ventilation.

An option is to buy a dedicated anti fungal paint, the dulux bathroom range do a white which should last years. It does require a little prep on the surface beforehand and 2 coats but it lasts.