Durham

When installing trench & sump, bolt-down cast iron grates & frames, both types require the grate and frame to be assembled, (bolted together) prior to installation.

The trench formwork must be measured from the clear opening size of the grate & frames (As shown in the diagram). The grating should be installed on a level, even surface.

When installing B.R. Durham & Sons bolt down grates & frames the units should be set out and cast in one go/pour. The concrete must be a minimum 32 Mpa rating and should be poured around the base and side of the frame. (NOT by grouting in the base and concrete pouring the sides). The concrete should also be vibrated to remove air ‘pockets and allow the concrete to surround the frame completely.

Should the base & sides of the frames not be cast in one go/pour the nut if present retaining the bolt will not function in the manner required. It is very important therefore the nut be set properly in the concrete so that it will not spin when trying to unbolt the grates from the frames.

The concrete must be allowed to cure/set correctly. Failure to allow this to happen will result in the product failing to be retained by the mechanical fasteners.

NOTE: Should our products be deemed to be incorrectly installed, B.R. Durham & Son will take no responsibility for the resulting damage to our products, surrounding works or any other damage or incident resulting from the incorrect installation.

B.R. Durham & Sons manufacture a range of quality products to comply with AS 3996 - 1992.

Only these certified quality products proudly display the Benchmark Conformance logo, Licence number and other relevant marking requirements.

Ensure the concrete fully supports both the side & underside of the frame