Hello everyone, The background is that about 6 months ago we have put a baby playmat on top of a small area of oak floorboards. Today I lifted the playmat up and saw these dark lines across several joints which weren’t there before. Does anyone know what caused this?
Possibly moisture, one possible cause could be if the floor has been cleaned and not completely dried before putting the mat back ,trapping the moisture under the mat, you could try using lemon juice to bleech the marks out
