The intersection where reveal masonry meets a sill formed in brick, tile or stone, is an area most susceptible to water volumes and water ingress. An effective union with the reveal closing arrangement is therefore essential, Cavity Trays advises.<br> <br> Forming a masonry sill also requires the individual sill bricks, tiles or stones to adopt a bedded angled presence, and this has to be achieved without physical connection with the inside skin.<br> <br> The Type U Undersill tray by Cavity Trays of Yeovil is a profiled dpc tray that beds into position with the sill being constructed on it. The Type U tray remains enveloped in the wall and provides the dpc qualities required to prevent damp ingress.<br> <br> Initially the Type U also functions as sill formwork – there are two support areas on each Type U tray and the dimensions of these are variable.<br> <br> Once bedded, the sill masonry construction can begin. When the sill has cured, a grooved detachment line allows the front lip of the tray to be removed, leaving just the sill masonry projecting.<br> <br> www.cavitytrays.co.uk