JAS Siphonic

JAS Siphonic is a specialist supplier of Siphonic Roof Drainage Systems. We are a leader in siphonic rainwater management, with a design base of more than 35,000 systems worldwide. We provide design, JAS siphonic outlets, HDPE piping systems, supervision and installation services that can support our client needs whilst creating specific benefits and integration for your building project.

The JAS Siphonic system is the solution to your rainwater management needs and will overcome design limitation, help reduce project cost by up to 60%. JAS Siphonic outlet can drain 10 times faster than a comparable Gravity outlet.

Our Innovative Technology

Reasons for choosing JAS Siphonic

Engineers & Architects

  • No slope required for horizontal main pipe, providing more usable space
  • Flexible Pipe routing, Pipework can be located according to requirements of architect/engineer
  • Smaller diameter pipe with easier installation
  • Better Rainwater Management, pipework can be routed to storm tank without an electrical pump


  • Project cost saving up to 60%
  • Reduced construction time due to less underground work, fewer manholes and less pipework
  • Fast response to changing requirements on site by our on-line design team and on-site supervision service

Owners & Clients

  • High-performance roof drainage system, allowing self-cleaning action
  • Design warranty worldwide by Lloyd’s, the world’s leading insurance company
  • Smaller and fewer downpipes designed according to client/owner convenience