Hello all
Can anyone identify if this is mold or a left over of the manufacturing process of the OSB?
Whilst fitting insulation board between my rafters I noticed my osb has some mold like marks on the under side. The room at the moment isn't heated but has been kept shut most of the time. The windows and doors have trickle vents open all the time and sticking my hand by the soffit vents I can feel a trickle of air come in although it is faint.
Scrubbing the marks with watery tissue paper slightly fades and smudges them but they do not wipe cleanly.
Can anyone identify if this is mold or a left over of the manufacturing process of the OSB?
Whilst fitting insulation board between my rafters I noticed my osb has some mold like marks on the under side. The room at the moment isn't heated but has been kept shut most of the time. The windows and doors have trickle vents open all the time and sticking my hand by the soffit vents I can feel a trickle of air come in although it is faint.
Scrubbing the marks with watery tissue paper slightly fades and smudges them but they do not wipe cleanly.