Cov kav dej yog cov khoom siv tsim nyog rau cov haujlwm tsim kho, thiab feem ntau siv yog cov kav dej xa dej, cov kav dej ntws, cov kav roj, cov kav dej cua sov, cov kav hlau, cov kav dej nag, thiab lwm yam. Nrog rau kev txhim kho ntawm kev tshawb fawb thiab thev naus laus zis, cov kav dej siv hauv kev kho kom zoo nkauj hauv tsev kuj tau ntsib cov txheej txheem kev txhim kho ntawm cov kav hlau cam khwb cia → cov kav dej cement → cov kav dej pob zeb reinforced, cov kav dej asbestos cement → cov kav hlau ductile, cov kav hlau galvanized → cov kav yas thiab cov kav dej txhuas-yas sib xyaw.

Muaj ntau yam kev siv cov kav dej, tab sis lawv muaj cov ntaub ntawv sib xws uas yuav tsum tau saib xyuas - qhov txoj kab uas hla sab nraud, uas yog ib qho ntawm cov yam tseem ceeb los ntes seb cov kav dej puas tsim nyog lossis tsis tsim nyog. Peb lub Hoobkas tau teeb tsa cov khoom siv tshaj lij los saib xyuas cov ntaub ntawv txoj kab uas hla sab nraud ntawm cov kav dej hlau txhua lub sijhawm kom ntseeg tau tias cov khoom zoo. Peb lub Hoobkas tshwj xeeb hauv kev tsim cov kav dej hlau, cov kav dej hlau tsis muaj qhov sib txuas, cov kav dej hlau galvanized, cov phaj hlau, cov khoom siv scaffolding thiab cov khoom siv scaffolding, cov kav dej tsev cog khoom, cov kav dej xim coated, cov kav dej txau.