Bought an old end of terrace (1906) house about 8 months ago.
All of a sudden this morning I noticed some strange oily spots appear under the windowsill. This is an external wall and generally the room is pretty well ventilated. Gets warm in that room, at the back of the house, during the morning but cools down as the day goes on. There’s a chimney breast in that room but not on the concerned wall where the spots are. Half of the concerned wall adjoins to the bathroom and the other half is just brickwork on the other side as it’s external facing. The window is usually cracked open at all times. Was pretty hot yesterday but it was hotter for a longer period a few weeks ago so not sure it’s that
Any ideas?
Pics attached
All of a sudden this morning I noticed some strange oily spots appear under the windowsill. This is an external wall and generally the room is pretty well ventilated. Gets warm in that room, at the back of the house, during the morning but cools down as the day goes on. There’s a chimney breast in that room but not on the concerned wall where the spots are. Half of the concerned wall adjoins to the bathroom and the other half is just brickwork on the other side as it’s external facing. The window is usually cracked open at all times. Was pretty hot yesterday but it was hotter for a longer period a few weeks ago so not sure it’s that
Any ideas?
Pics attached