The National Chimney Sweep Guild (NCSG) is a non-profit trade association for chimney sweeps and chimney and venting manufacturers in the United States and Canada. Based in Plainfield, Indiana, it has approximately 1,100 member companies. Member companies range in size from the owner-operator sole proprietor chimney sweep companies to those with 15+ vehicle crews and manufacturers with hundreds of employees. In 1986, NCSG published the first edition of Successful Chimney Sweeping, the first manual to set a standard for chimney service practices ever written.