Abstract: A manhole riser extension assembly including separate upper and lower spacer rings which are assembled utilizing tabs that extend downwardly from the upper spacer ring about the lower spacer ring, and locking elements in association with the lower ring that cooperatively engage and bear radially outwardly against the tabs, respectively, to urge and/or lock the tabs against an inner surface of the manhole frame bounding the manhole cover seat, or to penetrate the tabs and bear against the inner surface, to hold the assembly together and in place in the manhole frame, and such that a manhole cover is positionable in sitting relation on the lower spacer ring, bounded by the upper spacer ring for covering the manhole. Optional lift protections tabs can be provided at locations about the upper spacer ring, in position to be covered by paving material to supplement the holding of the assembly in place.

Abstract: A manhole riser extension assembly including separate upper and lower spacer rings which are assembled utilizing tabs that extend downwardly from the upper spacer ring about the lower spacer ring, and locking elements in association with the lower ring that cooperatively engage and bear radially outwardly against the tabs, respectively, to urge and/or lock the tabs against an inner surface of the manhole frame bounding the manhole cover seat, or to penetrate the tabs and bear against the inner surface, to hold the assembly together and in place in the manhole frame, and such that a manhole cover is positionable in sitting relation on the lower spacer ring, bounded by the upper spacer ring for covering the manhole. Optional lift protections tabs can be provided at locations about the upper spacer ring, in position to be covered by paving material to supplement the holding of the assembly in place.