Lub qhov rooj hluav taws uas siv hauv tsev yog qhov ntsiag to thaum nws qhib thiab kaw, thiab yuav tsis muaj suab nrov. Lub qhov rooj hluav taws steel siv sab nraum zoov tuaj yeem ua lub luag haujlwm zoo ntawm kev tiv thaiv tub sab nyiag ntxiv rau kev tiv thaiv hluav taws. Ntoo qhov rooj hluav taws thiab lub qhov rooj hluav taws steel zoo ib yam li kev tiv thaiv hluav taws, tsis muaj qhov sib txawv ntawm qhov zoo thiab qhov tsis zoo, tsuav yog lawv nyob ntawm tib theem, cov nyhuv zoo ib yam.