Installation of Handholes / Pull Boxes and Vaults:

Please refer to local utility for installation guidelines. These installation guidelines are for reference only, proper installation shall be the sole responsibility of the contractor.

Digging

A firm base for the enclosure is very important. A layer of at least 6" of aggregate is recommended under the enclosure. This is for support as well as drainage. Excavate an area roughly 12-18" larger than the base of the box and 6" deeper to accommodate the aggregate. Ideally you want the box at final grade, so you need to determine the depth of the hole compared to the height of the enclosure you are installing.

Base Preparation

The bottom flange must rest on a firm foundation. Use approximately 6" of compacted materials such as gravel, soil or stone dust. After the enclosure has been placed in position and leveled, 3" of soil should be placed on the flange to keep the enclosure in place.

Backfilling

Back filling the exterior wall can be typically done by using clean loose material excavated from hole. Backfill in 6" increments. Avoid using oversized stones, rocks, concrete, frozen chunks etc. Pack the backfill by tamping. Do not use mechanical equipment for vigorous tamping, and do not compact around the box pad by driving vehicles next to it.

Larger enclosures should be braced from the inside by use of 2x4’s.

Important issues

• Any drilling or modifications to the enclosure should be done with care. Do not cut the flange, as this is the support hoop. Do not use sand as backfill. Sand provides no frictional resistance to movement, and actually creates tremendous side wall pressure.


• ALWAYS backfill the enclosure with the cover bolted in place.


• It is recommended that a 10-12" x 12" concrete collar be poured around the enclosure in areas where it is expected that soil would wash away or otherwise be disturbed by heavy lawn mowers, etc. If enclosure is being installed in a sidewall or area where it may be driven over it should also have a concrete collar. This protects the sidewall of the ring, which is not meant to withstand impact.