Conduits are generally installed with slope allowing water to drain into cable pits positioned at sag points along a cable route. Cable pits are generally not supplied with waterproof covers. To minimise the amount of standing water in the enclosure and in the conduits, a drainage point should be connected from the base of the pit to a suitable soakaway. All ACO cable pits are supplied with either a preformed hole (plastic pits) or a drillout hole (pits). Holes are typically 25mm diameter or similar.
In some applications, telecommunication carriers may require up to a 300mm clearance below the lowest conduit entry for drainage purposes.
For landscaped applications, where only foot traffic is anticipated, it is recommended that at least 150mm of gravel base is laid at the bottom of the pit. ACO recommends compaction no less than 60% RDD. The gravel acts as a drain and will help prevent the enclosure from sinking.
Conduits entering buildings should be installed to stop liquid from draining into the building. The simplest method is to make the exit end of the conduit (inside the building) higher than the external entry, while still applying sealing around the penetration of the building and within the pit wall.