Ki te whakapūmau i ngā kō whatu, me hiahia ki tētahi pūtau whakakore e āheinga ana i ngā āhuatanga o ngā kō whatu. Nga kō whatu iti wehi nei, pērā i ngā pakipaki, ka taea te whakapūmau i raro i ngā pūtau whakakore iti, pērā i ngā pūtau whakakore aluminium e rima rānei, nō te kimihana. Ka whakatakoto i ēnei pūtau i runga i ngā wā e toru, ka tīmata i ngā pūtau karu e mohio ana ki te whakatika, ka whai hoki i ngā pūtau karu whakapūmau nui mo te whakamutunga. Nō ngā kō whatu nui wehi nei, pērā i te kō whatu, me hiahia ki ngā pūtau whakakore nui wehi, pērā i ngā roa whakakore kimihana. Ko te whakapūmau he whakapai ake i te āhua o te kō whatu, engari ka whai hua hoki hei whakatū tonu i te whiu me te wehe, kāore anō ka whai hua hei whakamahere i te hanga me te ararau taonga.