Technical Questions - ACI Concrete Knowledge Center
Concrete cover required for specific fire rating
Q. How much concrete cover is needed for a concrete slab to meet a 4-hour fire rating?
A. The fire-resistance rating, sometimes called the fire rating, is a legal term defined in building codes. You can get guidance on the cover needed for different fire ratings in ACI 216.1-97/TMS 0216.1-97, “Standard Method for Determining Fire Resistance of Concrete and Masonry, Construction Assemblies.”
The values for slabs shown in Table 2.3 of ACI 216.1-97/TMS 0216.1-97 represent minimum cover for concrete floor and roof slabs for various aggregate-type concretes in restrained or unrestrained conditions.
Disclaimer: Questions in this column were asked by users of ACI documents and have been answered by ACI staff or by a member or members of ACI technical committees. The answers do not represent the official position of an ACI committee. Only a published committee document represents the formal consensus of the committee and the Institute.