Among the reported building violations for 5642 S Calumet Ave, most are normal. Some repair to doors, finishes, and walls here. Replace monoxide detectors there. And of course, the usual reminder that this repair work will require a permit and submission of plans by an architect. However, there was one particular violation that caught my eye:
The comments elaborate that the joists are exposed and, as part of the floor structure, need to be fire-protected. Normally, floor construction over a basement are required to be one hour rated or subject to normal floor requirements based on the type of construction. 13-60-200 covers basements:
And table 13-60-100 covers floor construction in general:
For those who don’t know, fire ratings are organized by how long a fire could theoretically burn and spread through a construction element or material. So a 1 hour floor is supposed to take an hour to burn through. This is to slow the spread of fire to allow for occupants to escape in the case of emergency. The table above says that the rating requirement of a floor depends on how the building is made and what materials it’s made from.
Under older versions of the building code, these “construction types” may not have existed or functioned under the same requirements they do today. Though building code had been in effect and updated many times before, according to the Encyclopedia of Chicago website there was a major update in 1957 that may have resulted in these standards. According to the county assessor’s website, 5642 S Calumet Ave is 102 years old, which allows it to take advantage of “pre-ordinance” sections of the building code. That’s why the floor structure only needs to be 1/2 hour rated rather than 1 hour rated like newer buildings.
Existing and historical buildings have a number of sometimes reduced and sometimes more stringent requirements, and it often takes a keen eye of the code and thorough research to recognize when it applies.