I recently noticed a cluster of yellowish stains on my downstairs living room ceiling, starting about 30cm in from the exterior wall. They all flow out from the joist. Photos attached.
I can’t figure out what’s caused them. I am not sure how long they’ve been there (could be a while), they don’t feel wet to touch, and I can’t see any issues directly above (though I will need to lift the floorboards to take a proper look).
There is a bedroom above, with no water, radiator or drainage pipes anywhere near the stain site.
Has anyone any ideas as to what it might be?
Many thanks in advance for your help.
I can’t figure out what’s caused them. I am not sure how long they’ve been there (could be a while), they don’t feel wet to touch, and I can’t see any issues directly above (though I will need to lift the floorboards to take a proper look).
There is a bedroom above, with no water, radiator or drainage pipes anywhere near the stain site.
Has anyone any ideas as to what it might be?
Many thanks in advance for your help.