Foot Kamba - 50 meters

Fibreglass scrim tape on a 50 metre roll, stocked as foot kamba. It is the open mesh laid into the joint between two gypsum boards before it is filled: the mesh spans the gap and holds the filler together across it, so the small movement every building makes shows up as nothing rather than as a hairline crack running the length of the wall. Any board joint left untaped will crack eventually, which is why taping is not an optional refinement but the step that decides whether a ceiling still looks right in two years. Also used over crack repairs in plaster and render before skimming. Press it flat into the first coat of filler with no bubbles or ridges, and let it dry before the second.