Retractable fabric needs controlled falls/tension when closed.
FASGAR · DRAINAGE
Retractable roof drainage planning.
A retractable roof only works as weather cover when the closed membrane and drainage path are treated as one system.
SHORT ANSWER
Draw the water path from membrane to final discharge.
Confirm membrane/roof fall, water collection edges, gutters/channels, downpipes and the local discharge point. Avoid low points that can pond and keep drains accessible for inspection and cleaning.
KEY PROJECT POINTS
What should drive the decision.
These are project inputs, not substitute engineering or automatic product approvals.
Ponding can overload or distort the roof.
Wind-driven rain may bypass edges not intended as sealed walls.
Downpipe capacity and discharge are local project interfaces.
Leaves/debris can block small gutters and outlets.
The open/parked roof state should not obstruct drainage.
Start at the highest point
Show how water moves across the closed roof rather than assuming it will find the gutter.
Avoid ponding geometry
Membrane tension, bay width and support geometry should prevent broad low points where water can collect.
Separate roof drainage from site drainage
The roof can collect water, but the project still needs a defined stormwater/discharge route beyond the supplied system.
Make outlets cleanable
Gutters and drains should remain accessible to remove leaves and debris before they reduce performance.
PROJECT INPUTS
What to have ready before asking for the exact system.
A stronger brief shortens the gap between product interest and a useful technical/commercial response.
Roof dimensions
Membrane/roof fall
Bay geometry
Gutter locations
Outlet quantity
Downpipe route
Site stormwater/discharge
Wind-driven rain exposure
Adjacent walls
Open/closed roof states
Debris/trees
Maintenance access
EVIDENCE BOUNDARY
Drainage capacity and geometry must match the exact roof configuration.
Use exact drawings for gutters, membrane geometry, outlets and downpipes. Local stormwater design and final discharge remain project responsibilities.
FAQ
Questions project teams usually need answered.
Can a retractable fabric roof be completely flat?
A weather-covering membrane generally needs controlled geometry/tension and drainage; exact design comes from the selected system.
Who designs the final stormwater connection?
The local project team is responsible for site drainage/discharge beyond the supplied roof interfaces unless expressly included.
Why is ponding a problem?
Standing water adds load and can deform fabric or overload components.