The Type B semi-rigid vertical cavitray may be introduced into the existing exterior skin of a cavity wall following vertical cutting of the masonry to provide a 4mm slot. The Type B establishes a permanent DPC presence. Addressing this vertical requirement in addition to any horizontal requirement (see Type E) is important where a skin changes status by virtue of an extension being added to an existing structure. Where metal profile links are employed to attach masonry and the existing wall is not cut-out to create T-junction cavity continuity, the Type B approach can introduce DPC integrity. See separate page entry for Cavilinks. Features Black polygormac DPC Standard 2440mm lengths. B1 suits standard brickwork skin. B2 150mm skins B3 225mm skins.