Wood-decaying fungi are most commonly found in woodwork, but some fungi (e.g. true dry rot) can also grow in other building materials such as masonry and concrete.

Wood-decaying fungi often form fruiting bodies with caps and sticks or grow as brackets, as often seen on trees in the forest. Many fungi also grow over building materials. When they are warty, they are called mycelia. When they are filamentous, they are called string mycelia.

Wood-degrading fungi can degrade wood in two ways. When a fungal attack degrades the wood over a very short period of time (a few years or months), the degradation state is called 'fungal'. When the wood degrades very slowly (over many years), the degradation state is called 'rot'. The difference is important for insurance purposes.

Unlike moulds, wood-degrading fungi can degrade wood, causing it to crack across or along the grain.

See PROTOX Photo Guide for images of mushrooms.