Roof Drainage Systems & Rainwater Outlets

Effective roof drainage is essential for safely removing rainwater from a roof and protecting the building from water ingress, ponding and damage to the roof structure. With over 35 years experience of in supplying and designing Roof and Floor Drainage products, Caroflow supplies a range of roof drainage products designed to provide reliable drainage from flat roofs and other roof areas, including rainwater outlets, roof gullies and drainage outlets.

Whether you are specifying a new roofing system, replacing an existing outlet or looking for a suitable drainage solution for a refurbishment project, choosing the right roof drainage products is essential for effective and reliable rainwater management.

All Caroflow roof drainage products have a fire classification rating of A2-s1, d0.  For further information regarding the Fire Classification of our products, please click here

Choosing the Right Roof Drainage Solution

The correct roof drainage system will depend on several factors, including the roof design, roof area, construction and waterproofing system.

When selecting a drainage outlet or rainwater outlet, consider:

• Roof area: The drainage system needs sufficient capacity to handle the volume of rainwater expected from the roof.
• Roof construction: Warm, cold and inverted roofs may require different drainage arrangements.
• Waterproofing system: The outlet must be compatible with the roof membrane and allow a secure, watertight connection.
• Outlet position: The location and configuration of outlets should allow rainwater to drain effectively from the roof.
• Drainage pipework: The outlet should be suitable for connection to the required drainage system.
• Maintenance: Outlets should remain accessible and protected from leaves, debris and other materials that could restrict water flow.
• Overflow provision: Appropriate overflow measures may be required to reduce the risk of water accumulating on the roof if a primary outlet becomes blocked.

Correct roof drainage design is particularly important on flat roofs, where inadequate drainage can result in standing water and increase the risk of water entering the building. UK Building Regulations include provisions for the adequate disposal of rainwater from roofs.