Warehouse & Distribution Center Drainage

Drainage by Application

A distribution site is acres of roof and pavement draining past docks, gates, and door thresholds — with forklifts crossing the drain lines inside and 80,000-pound trucks crossing them outside. The right answer is rarely one product; it is a system specified area by area.

What fails on a distribution site

Outside, truck courts pool at the gates and dock approaches because vast flat catchments converge on a few low points; standing water heaves in winter and undermines joints year-round. At the building line, wind-driven rain and sheet flow slip under overhead doors unless a trench intercepts them at the threshold. Inside, wash-down bays, battery-charging areas, and fire-riser rooms all generate water on a slab that was poured nearly flat. And the traffic is deceptive: the grate that shrugs off a semi tire can crack under a loaded forklift, because small solid wheels concentrate the same weight on a fraction of the contact patch. Drainage here gets specified by area — not by the biggest vehicle on site.

Load class guidance

Truck courts and aprons are generally Class D (400 kN), stepping to Class E (600 kN) where trucks brake and turn at gates; hard-wheeled forklift crossings deserve heavy-duty treatment regardless of vehicle weight; employee parking is typically Class C or below. The load class recommendation guide maps all six EN 1433 classes.

Recommended systems

Door thresholds & forklift crossings

ACO PowerDrain

Polymer concrete channels with integrally cast ductile iron edge rails and published loading to EN 1433 Class F as a complete system — built for the drain lines equipment crosses every shift. Locking ductile iron grates stay seated under repeated hard-wheel impacts; 4-, 8-, and 12-inch widths (S100K–S300K) match flow to the run.

Commercial trench drainage system installed across a concrete truck court

Truck courts, gates & dock aprons

ACO KlassikDrain K200 / K300

Modular polymer concrete in 8-inch (K200) and 12-inch (K300) widths for the long, high-flow runs of a truck court, with galvanized or stainless edge rails and a deep grate catalog. Load classification varies by grate and model — confirmed per component at quote.

Perimeter pavement & employee parking — orderable online

NDS Dura-Slope Trench Drain

A pre-sloped channel system that builds fall into the run — a cost-effective fit for car parking, sidewalks, and lighter service pavement around the building. Grate options run up to ductile iron for vehicular duty; channels and grates can be ordered directly online. See the Dura-Slope FAQs & resources.

Yard low points & storm collection

Catch Basins

Square and round catch basins collect trench outlets and yard low points into the storm system and give long runs mid-point cleanouts — essential on sites where drain lines swallow stretch wrap and pallet debris. Size the collection piping with the runoff calculator.

Josam Pro Plus polymer concrete trench drainage is also available on request for industrial interiors and wash-down areas.

Planning resources

Load Class Recommendation Guide — EN 1433 classes A–F explained
Sizing for Storms: Estimating Runoff — sizing big flat catchments honestly
Runoff Calculator
NDS Dura-Slope FAQs & Resources

Warehouse drainage FAQs

What load class does a warehouse truck court need?

Truck courts and trailer parking are generally EN 1433 Class D (400 kN) duty, stepping to Class E (600 kN) where trucks brake, queue, or turn hard at gates and dock approaches. Employee parking is typically Class B or C. Confirm channel, grate, and embedment together as a system against the site's traffic plan.

Why do forklift areas need a higher-rated drain than truck lanes?

Contact patch. A loaded forklift on small solid wheels presses its weight through a few square inches of tread, so the point load on a grate bar can rival or exceed what a highway truck tire applies. Wherever hard-wheeled equipment crosses a drain line daily, specify a heavy-duty system with locking metal grates rather than sizing from gross vehicle weight alone.

Do you supply complete packages — channels, grates, basins, and outlets?

Yes. Send the site plan or a sketch with run lengths, load classes by area, and outlet points, and we will take off the full system — trench channels, matched grates, catch basins, and fittings — and return one project quote covering all of it.