Surface mounted grid for ventilation shaft to cellar has a pressed metal construction with a raster of round holes with raised edges surrounded by profiled water drainage ducts

摘要

A surface mounted grid for fitting to a ventilation shaft to a cellar has a plate of pressed metal sheet (1) stamped with a square raster of round holes (2) of about 6 mm diameter. The holes are surrounded by raised edges to form drainage ducts which feed into the spaces (5) between the holes and to drains at the sides of the duct. The edges (7) of the plate slope outwards and down and the centre of the plate has a captive nut for a flyscreen fitted under the grid, and for securing an optional outer water sealing plate.