(225 ILCS 705/31.26)
(from Ch. 96 1/2, par. 3126)
Permanent overcasts shall be constructed of incombustible
material such as masonry, concrete, concrete blocks, or metal and shall be
of ample area to pass the required quantity of air, and where necessary to
securely timber to prevent falls from the roof.
(Source: Laws 1953, p. 701.)