A Beginner’s Guide to Trench Drain Systems: Efficient Water Management Solutions

For those of us unordained in the technical world of drainage, choosing the right trench drainage system requires some thought. In the drainage industry, terms like mechanical keying, anti-shunt lugs, integrally cast-in steel rails and knockouts are thrown around willy-nilly. Separately, these words might mean something to you. Together, they are meaningless.

And then there are choices between various styles and materials you’ve never heard of. New age materials, finite element analysis, purpose specific load features, binders, aggregates, shock-absorbing widgets — they must (and do) mean something to somebody.

So, to uncover the mystery of technical drainage terminology, let’s examine some of ACO’s grated trench drainage products, the parts and materials that constitute them and find out how the terms apply.

Trench Drain Systems
Trench drains (channel drains) are surface drainage systems designed to manage surface water that can cause safety hazards and damage pavement and property. At ACO, we primarily offer grated trench drainage systems because of their superior design features compared to grated pit and pipe systems.

Grated trench drainage systems are simple to design and construct, easy to install and require minimal underground piping, reducing excavation costs. Within ACO Drain’s range, KlassikDrain, SlabDrain and PowerDrain systems are examples of grated modular trench drainage systems.

Materials: Trench Drain Systems
ACO Drain commercial grated trench systems are manufactured from Polycrete®, ACO’s trademark for castings made from polymer concrete, a durable, lightweight composite material made from polyester resin binder reinforced with mineral aggregates and fillers.

ACO’s KlassikDrain, SlabDrain and PowerDrain channels are all manufactured from polymer concrete. The bodies of the channels are therefore highly resistant to chemical attack and, with the appropriate grate, can be used in most environments where acids and dilute alkalis are encountered. When greater chemical resistance is required, stainless steel channels are available.

Fig 1. KlassikDrain range

Trench Drain Grates
Trench drain grates are the covers through which the excess surface water passes into the drain. Because grates in many locations will need to withstand heavy loads, they need high tensile strength (maximum yield stress before breaking). Still, the particular type and material of the trench drain grate will depend on specific loading, installation and application requirements.

Unlike the trench drain body, grates can be removed, changed or easily replaced after installation, which is important for drain maintenance. Perhaps of higher importance, though pedestrain safety. This is why many of our trench drain grates are trademarked for their slip resistance properties, complying with Australian Standards for wheelchair, bicycle and heel safety.

Materials: Trench Drain Grates
Multiple trench grate styles are available, with various levels of slip resistance. These are marketed as ACO’s Heelsafe® Anti-Slip Range. A variety of materials is offered; the most common are ductile iron, mild steel, stainless steel and plastic.

Fig 2. Cost-effective black polypropylene longitudinal grate. Ideal for use in pedestrian areas.

Edge Rails
Edge protection rails should be integrally cast-in or mechanically connected to the trench body to prevent movement for optimum strength and protection.

Materials: Edge Rails
In ACO Drain’s KlassikDrain, SlabDrain and PowerDrain trench drain systems, galvanised steel, stainless steel or ductile iron edge rails are integrally cast. The edge rail is the exposed edge of the trench, which helps hold the grate in position. Because it is exposed to the same loads as the trench drain grate, it needs to be extremely secure. If the edge fails, the grate will move out of place, which could cause catastrophic failure.

The edge rails are fitted with lugs which interlock with recesses in the grates to prevent longitudinal movement (see Fig 3).

Fig 3. Anti-shunt lugs