Ntawm cov qhov rooj steel fireproof, Qib A steel fireproof qhov rooj muaj qhov muaj zog tshaj plaws. Nws qhov hluav taws kub yog 1.5 teev, uas yog tsis yooj yim sua rau Class B thiab C qhov rooj hluav taws. Feem ntau, steel qhov rooj hluav taws yog ib qho tseem ceeb heev.

hluav taws qhov rooj Hoobkas,ul hluav taws qhov rooj ntsuas,hluav taws qhov rooj 1 teev, hlau hollow qhov rooj,hlau rooj vag qhov rooj, qhov rooj xauv qhov rooj qhib thaum muaj xwm ceev,hluav taws qhov rooj xauv,

hluav taws kub ntsuas hlau qhov rooj tsum,ul hluav taws qhov rooj ntsuas,txhim kho qhov hluav taws kub nyob hauv qhov chaw nres tsheb, hluav taws kub ntsuas hlau qhov rooj jambs,hlau rooj vag,hlau pem hauv ntej qhov rooj,Lub qhov rooj xauv qhov rooj qhib qhov rooj thaum muaj xwm ceev,

Thaum muaj xwm ceev hluav taws kub tawm qhov rooj, khoom siv thaum muaj xwm ceev qhov rooj,ul hluav taws qhov rooj ntsuas,Hluav taws kub resistant qhov rooj rau tsev, hluav taws kub resistant qhov rooj rau flats,hlau rooj vag,hluav taws tawm qhov rooj qhov ntev,thaum muaj xwm ceev qhov rooj xauv qhib