Dry rot species of fungi cause brown rot decay, preferentially removing cellulose and hemicellulose from the timber leaving a brittle matrix of modified lignin. The term "dry rot" is somewhat misleading, as both species of fungi "Serpula lacrymans" and "Meruliporia incrassata" require an elevated moisture content to initiate an attack on timber (28–30%). Once established, the fungi can remain active in timber with a moisture content of more than 20%. At relative humidities below 86 percent, growth of "Serpula lacrymans" is inhibited, but it can stay dormant at relative humidities down to 76 percent. These relative humidities correspond to equilibrium moisture contents
Society for the Protection of Ancient Buildings Society for the Protection of Ancient Buildings The Society for the Protection of Ancient Buildings (SPAB) (sometimes known as Anti-Scrape) is an amenity society founded by William Morris, Philip Webb and others, in 1877; to oppose what they saw as destructive 'restoration' of ancient buildings then occurring in Victorian England; 'ancient' being used in the wider sense of 'very old' rather than the more usual modern one of 'pre-medieval'. Morris was particularly concerned about the practice, which he described as 'forgery', of attempting to return functioning buildings to an idealised state from the distant past, which often involved the removal