Froet Industries 
Manufacturer of innovative roof drainage products, including the industry's only bi-functional roof drain, a primary and overflow drain all in one unit. That’s right, only one roof membrane penetration. Great for LEEDS/Rainwater Harvesting projects, reduces roof drain fixtures in half and eliminates scuppers. Overflow sensors for roof drains.
Jay R. Smith Mfg. Co.
We have a complete line of roof drains for all roof types and applications, whether it is for a general purpose, secondary drainage, a custom made or special application product. We manufacture Siphonic Roof Drainage Systems designed to be used in conjunction with Rainwater Harvesting and Rainwater Management Systems.
Mifab Manufacturing 
Manufacturer of a complete range of roof drains including siphonic, parapet , overflow, controlled flow , IRMA style, ballast guards, parabolic weir, promenade deck, condensate receptor, side outlet, combination primary and secondary overflow, large sump, dexotex, standpipe, medium sump, balcony roof drains. Also manufacture downspout boots, cast iron vent caps, expansion joints and downspout nozzles.
Watts 
Since 1874 a leading manufacturer of water safety & flow control products, backflow prevention devices, water quality & conditioning products, specification drainage products, brass & tubular products, control valves, potable PEX plumbing products, Quick-Connect Push Fit Solutions, and Custom OEM Products.
Zurn Plumbing Products Group
is a family of specialty companies dedicated to producing "engineered" roof-to-basement water and water drainage controls for the residential, commercial, industrial and institutional building markets.
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See also:
33 4300 - Rain Water Harvesting Systems
33 4800 - Subsurface Retention/Detention Systems
Froet Industries
Manufacturer of innovative roof drainage products, including the industry's only bi-functional roof drain, a primary and overflow drain all in one unit. That’s right, only one roof membrane penetration. Great for LEEDS/Rainwater Harvesting projects, reduces roof drain fixtures in half and eliminates scuppers. Overflow sensors for roof drains.
Jay R. Smith Mfg. Co.
We have a complete line of roof drains for all roof types and applications, whether it is for a general purpose, secondary drainage, a custom made or special application product. We manufacture Siphonic Roof Drainage Systems designed to be used in conjunction with Rainwater Harvesting and Rainwater Management Systems.
Mifab Manufacturing
Manufacturer of a complete range of roof drains including siphonic, parapet , overflow, controlled flow , IRMA style, ballast guards, parabolic weir, promenade deck, condensate receptor, side outlet, combination primary and secondary overflow, large sump, dexotex, standpipe, medium sump, balcony roof drains. Also manufacture downspout boots, cast iron vent caps, expansion joints and downspout nozzles.
Watts
Since 1874 a leading manufacturer of water safety & flow control products, backflow prevention devices, water quality & conditioning products, specification drainage products, brass & tubular products, control valves, potable PEX plumbing products, Quick-Connect Push Fit Solutions, and Custom OEM Products.
Zurn Plumbing Products Group
is a family of specialty companies dedicated to producing "engineered" roof-to-basement water and water drainage controls for the residential, commercial, industrial and institutional building markets.