Distribution Box Supervision

This page provides guidance for completing format MF4-F75 “Construction_supervision” regarding DB supervision.

PROCEED n° MF4-F45	Rev 1.0	DB supervision checklist	September 2026

1	Foundation excavation & compaction
1.1	Check yield compare to design requirement MF4-M50 §3
1.2	Contractor knows inside dimensions of DB, Height given by design, L=30+15xoutlets number, W=60 for inlet ≤50, W=80 for inlet>50 MF4-M40 §1
1.3	Foundation depth is at least 60cm and length is at least = L+0.8m and width = W+0.8m MF4-M15 §1
1.4	Drop stone test pass (Mark < 1 cm)MF4-M15 §1
1.5	Overflow drainage point is chosen (check slope and surrounding)
1.6	Contractor knows masonry size & PVC pipes posit. in the foundation MF4-M40 §2

V2	Preparation for slab casting
2.1	Masonry height is matching design data (Masonry level = design level - 10cm) MF4-M40 §2
2.2	Masonry width and length is matching calculated DB inside dimensions (L & W) MF4-M40 §2
2.3	Inlet installed at least 5 cm clerance with the edge of masory MF4-M40 §2
2.4	Inlet diameter is matching the sketchmap
2.5	Outlets as per sketchmap, at least 15 cm clerance with edge of masory MF4-M40 §2
2.6	Outlets diameters are matching the sketchmap
2.7	Outlets air vents are correctly installed (Tee + elbow 20cm apart) MF4-M40 §2
2.8	Overflow is installed, end of PVC coupling are precisely located 10cm above masonry top MF4-M40 §2
2.9	All pipes are protected from foreign entrance with plastic bag attached by wire MF4-M40 §2
2.10	Rebar mesh (20x20cm ⌀8mm) installed around masonry (7-8cm clearance from it) and at bottom slab level MF4-M40 §3
2.11	Contractor knows wall & slabs thickness (15cm) and standards for metal door MF4-M15 §3 & concrete (1:2:3) handling MF4-M13

Supervisor has *2 mandatory validation visits*. If one item is not validated correction measures must be agreed with contractor and another visit must be organized. If not impossible penalties must be applied (up to contract termination)