Specifying Drainage for Parking Structures

A basement ramp carries heavier commercial traffic on a sloped surface where braking and acceleration add dynamic load beyond what a flat car park imposes. C250 is the appropriate classification for these locations under EN 1433.

Rooftop parking typically carries lighter passenger vehicles at low speed, making B125 appropriate. The distinction matters because over-specifying adds unnecessary cost, while under-specifying leads to premature grating failure at the seat.

A vehicle turning through a tight radius applies lateral force to the channel grating in addition to vertical load. In multi-storey parking, every bay entrance and ramp curve creates a repeated turning point directly over the drain run.

This repetitive lateral loading is more destructive than straight-line traffic of the same weight. The channel-grating seat is the failure point, which is why matching the assembly to the actual traffic pattern matters more than matching it to the nominal vehicle weight alone.

Parking structures concentrate fuel drip, oil spill and de-icing salt at the drain line. Metal channels corrode at the grating seat under prolonged chemical exposure, eventually loosening the grating fit.

Polymer concrete's resin matrix is chemically inert to hydrocarbons and chlorides. The channel body does not degrade under the chemical load a parking environment generates, which extends the service interval between seat inspections.