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
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.
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.
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.