How to Cement Around a Sewer Cover

Build a firm, stable platform for the sewer cover frame to rest upon. This is typically done using retaining walls of regular brickwork; these in turn are built on top of the cover slab used by the sewer-line or septic system installers. The cover slab -- a precast concrete panel called a “biscuit” in industry-speak -- tops off the inspection chamber that in turn leads to the sewer or septic tank itself.

Measure the internal dimensions of the sewer cover frame and build the retaining walls to that size and shape, increasing their height until the top course is approximately 4 inches below ground level. Tool the internal faces of the joints to be smooth.

Spread a layer of mortar over the top course of the brick walls, all around the entire structure. The thickness of the mortar should ideally be no greater than the joints used in the building of the retaining walls -- around half an inch -- but leveling the sewer cover is important. The mortar must be thicker in one place than another if this is necessary to make a level base for the sewer cover frame to rest on.

Bed the sewer cover frame into the layer of mortar, using a spirit level to ensure that it is perfectly level. Use a rubber mallet or the butt end of a 2-by-4 to tamp down high points until the frame is level in all directions, from side to side, from corner to corner and across the opening, both north-south and east-west.

Allow the mortar to set if the sewer cover frame is of a type that requires mechanical fastening. When the mortar is set -- if required -- drill down through the frame into the top course of the retaining walls and anchor the frame with the fasteners recommended by the manufacturer.

Extend the mortar up over the outer lip of the sewer cover frame, shaping it so that it forms a convex, rounded “shoulder” with its highest point at a level with the top of the frame, and its lowest point reaching the outside edge of the top course of the retaining wall. Shovel or trowel the concrete around the frame until it is roughly in shape, then trowel off until the “shoulders” are smooth and even all around. The proper name for this part of the structure is a haunch, but the term “collar” is also frequently used.