If there is any likelihood of grease or oil on a surface which is to be covered with concrete, the surface should, if practicable, be cleaned with petrol or a hot solution of soda.
Ukuba kungathi kukho igrisi/amafutha okanye i-oyile kumphezulu oza kugqunywa ngekonkrithi, umphezulu mawa, ukuba kuyenzeka, mawuqatywe ngepetroli okanye isoda enyibilikisiweyo eshushu.