A two-story combustible building with combustible stairs that is currently under construction will be enclosing the area underneath its stairways. Section 8.15 of NFPA 13 has contradictory statements on whether sprinklers are required to be installed in this space and I'd like to know which section should apply and why.
126.96.36.199 Concealed Spaces Requiring Sprinkler Protection.
Concealed spaces of exposed combustible construction shall be protected by sprinklers except in concealed spaces where sprinklers are not required to be installed by 188.8.131.52.1 through 184.108.40.206.18 and 8.15.6.
220.127.116.11.9 Concealed spaces over isolated small compartments not exceeding 55 ft2 (5.1 m2) in area shall not require sprinkler protection.
18.104.22.168 Combustible Construction. Sprinklers shall be installed beneath all stairways of combustible construction.
Thank you for your thoughts.