Spalted wood is prized by woodworkers for its beautiful array of colors and textures. I have avoided using spalted wood, thinking it to be simply “rotten”. While technically true, spalted wood can be used without compromising the project if mindful consideration is taken to the nature and type of spalting used.
Spalting occurs in wood when fungi grow and feed on wood. This process rots the tree and weakens its structure as well as creating discoloration in the wood. There are a few types of spalting, white rot, pigmentation and zone lines.
– White rot creates white spots in the wood when fungi consume the lignin or pigment in the cells. This type of rot is very destructive to the wood’s integrity and should only be used when strength is not a necessity.
– Pigmentation occurs when darkly colored fungi grow in the sapwood. This creates moderate damage to the cell structure and should be used accordingly.
– Zone lines are walls built by fungi to section off the wood from other fungi. This type of spalting does not effect wood structure but is indicative of the presence of fungi which are consuming and subsequently rotting the tree. Zone lines are safe to use when structure is a consideration but may contain other types of spalting.
Wilder Woodworking 