What is it?

[bclark]

Can anyone tell me what this is. It was found in the attic on the 1 by slats. I have never seen it before. It is definitely some kind of fungus.

[Stephen W. Stanczyk]

Wood rot fungus. Clear sign of roof leaks. There are three different classification of the fungi that degrades wood. Brown fungi, white fungi or soft rot fungi. The different classifications of fungi use different portions of the wood. The brown and soft rot fungi attack the carbohydrate portions of the wood that can lead to significant loss of strength. White fungi use all the wood components and can "eat" up to 97% of the wood weight. They are usually found on hardwoods.

There may be significant damage under that growth to both the slats and rafters/trusses. Warn them of this possibility.