Appendix 2-1. Roof Slopes and Fire Ratings for Various Materials
01 May 1999
Steep (Hydrokinetic) Roofing (cont'd)
17 25 33
Tiles - Cementitious, Clay and Metal
Materials require minimum 4 in./ft slopSoo e concrete and metal tiles cannot pass Class
A or B fire tests over combustible decks. Verify
listings in the UL, FM or other testing agency's
directory. Clay is considered non-combustible.
Some aluminum and steel tile products have Class
A ratings when used in conjunction with under-
layment or gypsum board.
EPDM = ethylene-propylene-diene terpolymer
Hypalon = chlorosulfonated polyethylene
PVC = polyvinylchloride
TPO = thermoplastic polyolefin
UL = Underwriters Laboratories, Inc.
FM = Factory Mutual
Source of Code Restrictions: ASTM E-108
Updated for this EI 1998
Originally published as Decision Guide for Roof
Slope Selection, 10/88, the Air Force Engineering
and Services Center, ORNL-6520.