Lub ntsiab kom zoo dua ntawm lub qhov rooj hluav taws yog kom muaj kev ncaj ncees thiab thermal rwb thaiv tsev ntawm lub qhov rooj lub cev rau ib lub sij hawm. Nyob rau hauv cov nqe lus ntawm qhov tseem ceeb hluav taws tsis kam, steel hluav taws qhov rooj yog qhov zoo tshaj plaws nyob rau hauv tib yam khoom, ob qho tib si nyob rau hauv cov nqe lus ntawm lawv tus kheej qauv thiab sab hauv filling.