Strange Stain - Damp or no Damp?

[jonsale]

Weird stains appearing on a lilac wall!

Recently a strange yelloish hue has appeared on our lilac wall. It doesn't feel weird or damp, the brickwork on the outside all seems good - any ideas what it could possibly be? It starts 3/4 of the way up the wall on the first floor of a victorian terrace house.

Not giving anyone much to go on really, but are there any gut feelings?

Thanks

 

[JohnD]

From the curtain, I deduce this is an external wall, right? Is there a chimney on the other side? Or a dripping gutter or downpipe?

My thoughts are of damp.

It looks like emulsion paint on plaster, is that right? how long ago was it painted? Was there formerly a heavy smoker in the house?

 

[jonsale]

It's external wall, front of the house. No downpipe, no leaky guttering at all as far as i can see, brickwork and cement is all sound. no airbrick or anything. The house was bought 2.5 years ago refurbished by a local builder. Plaster was reskimmed at this time - a pretty thin layer

We have never smoked in the house, not sure about the lady before us - she was about 90 years old and this is the bedroom so it seems unlikely.

I can see no indication of water/condensation etc being near this patch at all.

Should I just get someone to come and investigate?

 

[jonsale]

Oh.. yes, it's dulux silk emulsion ("lilac love!") on plaster. Painted about 2.5 years ago - reasonably soon after the plaster was done. Builders just painted everything magnolia so it was the 2nd coat.

 

[JohnD]

...I'm still thinking about damp... could there be a roof or plumbing leak dripping onto the wall in the loft? Worth a trip up there with your torch. Sometimes a roof leak is nowhere near the damp patch as water runs along the timbers or felt before dripping off.

 

[jonsale]

it was a new roof.. but we'll take a look

Thank you for your help!

 

[noseall]

if there has been some internal brickwork replaced, with contaminated or sooted bricks, this wouldn't be evident externally and would almost certainly cause "yellowing" internally. hacking off the plaster and either replacing the bricks completely, or using the s.b.r.and cement method, may be your only choice.

 

[mnb]

when was the roof re-newed? During the roofing work debris could have fallen down the cavity and you now have penetrating damp.
Any chance of an exterior pic? Is it clean brickwork or rendered or pebble dashed?
As was said you have to investigate in the loft with ample lighting and safe access - investigate all the loft/roof area and all plumbing.
Next try a ladder outside and examine brickwork and gutters and down-pipes. Again, roof work could have created a condition.
Someone foots the ladder and someone stands at the loft access for safety. If you are uncomfortable or doubtful about doing it then dont.

 

[JohnD]

victorian terrace house

so £50 says solid walls, no cavity.

 

[mnb]

johnD, good point. possible penetrating damp thro the beds or ponding behind fascia if felt short or sagging.