Txoj haujlwm ntawm cov rooj tog zaum hauv rooj tog yog qhov tseem ceeb heev. Qhov laj thawj vim li cas cov rooj tog zaum qib siab yog qhov zoo yog tias nws muaj cov ntaub ntawv zoo thiab muaj zog ua cov khoom siv tes ua haujlwm; ntawm qhov tod tes, qhov ua tau zoo ntawm cov khoom siv raug xaiv tau zoo, thiab nws lub luag haujlwm yog ua raws li kev teeb tsa ntawm cov rooj tog khoom vaj khoom tsev. Ntxiv rau cov khoom siv khoom siv, kev teeb tsa ntawm cov rooj tog khoom siv kho vajtse yog qhov sib txawv tseem ceeb ntawm cov rooj tog nruab nrab thiab qib siab.
Tus yuam sij rau qhov zoo ntawm cov rooj tog khoom vaj khoom tsev nyob ntawm tus du nto, thiab xyuam xim rau qhov kev xav ntawm qhib, xav kom du thiab dawb, tsis muaj suab nrov lossis nrov nrov. Qhov zoo ntawm cov rooj tog vaj khoom tsev ncaj qha cuam tshuam tag nrho zoo ntawm ib txheej rooj tog, uas yog qhov tseem ceeb rau kev siv li qub thiab lub neej ntawm cov rooj tog zaum. Yog tias cov rooj tog zaum muaj txiaj ntsig zoo yog tsim los ua qhov chaw zoo nyob, tom qab ntawd cov khoom siv yog lub elf hauv qhov chaw no, thiab nws yog lub luag haujlwm rau qhov twj ywm thiab kev nyab xeeb ntawm cov rooj tog zaum.
Qhov tsis yooj yim ntawm kev siv cov rooj tog yog feem ntau vim kev tsis raug lossis tsis muaj cov rooj tog zaum kho vajtse kom haum. Qhov ua tau zoo thiab qib ntawm cov rooj tog yeej lom zem ntau hauv kev xaiv ntawm cov rooj tog khoom vaj khoom tsev. Qhov poob tawm ntawm lub txee rau qhov rooj thiab lub suab tsis xis nyob feem ntau tshwm sim los ntawm cov khoom siv qis me ntsis. Kev lag luam feem ntau hais tias: "Tsuav ntev li muaj cov khoom sib xws ntawm cov rooj tog khoom vaj khoom tsev, cov khoom siv sib txuam ntau heev ntawm cov rooj tog zaum tuaj yeem tsim." Nws tuaj yeem pom tias lub luag haujlwm ntawm kev kho vajtse hauv rooj tog yog qhov tseem ceeb heev.
Cov khoom siv kho kom zoo cov rooj tog zaum yog qhov tseem ceeb ntawm kev ua kom zoo ntawm rooj tog, xws li qhov tseem ceeb ntawm cov hinges. Txawm hais tias qhov loj me, qhov hnyav thiab qhov hnyav ntawm lub qhov rooj, tsawg kawg peb lub duav yuav tsum tau nruab rau txhua lub qhov rooj kom ntseeg tau lub neej kev pabcuam qub ntawm lub pob khawm thiab tiv thaiv lub qhov rooj tsis sib dhos thiab deformed. Muaj ntau lub ntsiab lus yuav tsum nco ntsoov thaum xaiv lub pob khawm: ib qho yog xav txog cov khoom siv thiab cov qauv ntawm lub qhov rooj; qhov thib ob yog xav txog qhov loj, tuab thiab qhov hnyav ntawm lub qhov rooj; qhov thib peb yog xav txog qhov qhib zaus ntawm lub qhov rooj; qhov thib plaub yog xav txog cov nyhuv dai kom zoo nkauj; qhov thib tsib yog xav txog qhov av noo Huab cua, plua plav thiab lwm yam kev puas tsuaj puag ncig; thib rau yog xav txog tus nqi. Ib lub pob khawm zoo tuaj yeem sib phim raws li qhov chaw thiab qhov qhib ntawm lub txee rau lub qhov rooj, kom lub qhov rooj tuaj yeem ncab raws ntau yam mob.
Lwm qhov piv txwv yog qhov txawv txav sab sauv pob khawm uas ua rau nws yooj yim kom muaj qhov rooj zoo nkauj folding. Qhov khawm zoo li no kov yeej qhov tsis txaus ntawm txoj kev taug kev ib txwm dhau los uas yooj yim kom plua plav thiab tsis zoo nkauj, kom lub qhov rooj tuaj yeem xaub ywj siab raws li txoj kev khiav sab saud, uas yog qhov tshwj xeeb.