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TEP ROOF OY · PROJECT PLANNING GUIDE

Roof drainage and junctions

Drainage, penetrations and edge junctions are essential to roof performance. They form part of the same design as the waterproofing itself.

TEP-OK-05 · Version 1.1 · 12.10.2026

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Show the drainage routes

  • The design must show falls and water routes to drainage points. Water must be discharged without harming the building.
  • Match the outlet type and connection to both the waterproofing and the drainage system. Establish how a potential blockage or water build-up will be detected and its consequences managed.

Design the junctions together

  • Show eaves, upstands, penetrations, roof equipment and maintenance routes on the same roof plan. Check junction details at walls and interfaces with other contracts.
  • When roof equipment or additional insulation is changed, check the remaining upstand heights and unrestricted water flow. Later installations must not block drainage routes.

Plan for maintenance too

  • Agree inspections of outlets, leaf guards and junctions, together with safe maintenance access. Record findings and completed work in the building maintenance documentation.
  • Attach the roof plan, outlet schedule and necessary details to the request for a quotation. Identify existing areas of ponding or leakage and include photographs.

Use and design responsibility

TEP Roof Oy guide cards support project preparation and the definition of contract scope. They are not project-specific construction designs. The project structural designer is always responsible for checking the suitability of the solutions presented and adapting them to the project's structures, loads and requirements. Construction requires project-specific design and approval, together with the current manufacturer's instructions for the selected products.

Sources

An editorial compilation by TEP Roof Oy. The product- and system-specific source instructions must be checked for the selected solution.

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