Roof Drainage

A roof drain is installed level with a flat roof to collect rainwater and direct it into pipework. Gratings, domes or gravel guards help prevent debris from entering the outlet.

Roof drains remove rainwater from flat and low-slope roofs, preventing standing water and directing it into pipework. Specialist outlets are available for parapets, balconies and other specific roof drainage applications.

Commercial, industrial and multi-occupancy buildings with flat or low-slope roofs commonly use roof drains. Product selection depends on the roof construction, expected flow rate, connection requirements and project specifications.

A warm roof has insulation above the roof deck, while a cold roof generally has insulation below it. Each drain connects at the appropriate waterproof membrane level for that construction.

A lack of efficient drainage can cause significant damage to a roof. It prevents standing water, which can increase structural loads and contribute to membrane deterioration, leaks, damp and internal damage. Correct specification helps direct rainwater away.

Water passes through rainwater pipework to a surface water sewer, harvesting system, soakaway or attenuation system, depending on the site’s drainage design and project requirements.