The Mine fungus is very difficult to identify without any fungal growth, so as with any brown rot without growth you can't identify, just describe it as a 'brown' rot.
All growth, if present, is effectively pure white!
Mycelium - white, fernlike; can look like 'frost' on a window.
Strands - white, tough and remain flexible when dry. They can even be tied in a knot (Note:Dry rot strands are brittle when dry and usually grey).
Strands will grow long distances over damp masonry.
Fruiting body - white, fleshy with a small 'honeycombed' appearance on surface. Up to around 12 mm in thickness.
