Caroflow Roof Drainage Products 

 

Gulley Outlets Specifications 

The Caroflow Gulley Outlet Spigot is available in either LM6 Aluminium Silicon casting alloy to BS EN 1706:2010 for most roof finishes or in leaded gunmetal to BS EN 1982:2008 for use with lead or copper-clad roofs or for connection to copper pipework. 

Our Gulley outlets are available in two sizes; 75mm and 100mm. 

 

The codes and dimensions of each of our Gulley Outlets is as follows; 

 

75mm Gulley Outlet 

Code 

– 75/GOS 

 

A = 238, B = 144, C = 105, D = 125, E = 344, F = 240, G = 83 

 

100mm Gulley Outlet 

Code 

– 100/GOS 

 

A = 238, B = 144, C = 105, D = 125, E = 344, F = 240, G = 110 

 

The conventional Gulley Outlet is supplied with a Domical Grating as shown. However, a Flat Grating option is available if required. Please add the suffix “/F” to the above product codes to specify the Gulley Outlet with Flat Grating. 

 

Caroflow Gulley outlets are suitable for connection to, PVC, Aluminium, Cast Iron and Copper (Gunmetal only). 

Drainage Areas & Flow Rates for Gulley Outlets 

BS EN 12056-3:2000 (Gravity drainage systems inside buildings – Part 3: Roof drainage, layout and calculation) now specifically limits the drainage capacity that can be used to calculate areas to be drained, so as to prevent siphonic action that may damage internal pipework. 

 

Previous physical testing of all our outlets has shown that the rates and areas (see adjacent table) are lower than results that have been seen from this actual testing. 

 

All rates are assuming that the outlet grate is free and clear of any debris/blockages 

 

Results are based on a rainfall intensity of 75mm per hour and a 35mm head of water adjacent to the outlet (45mm head for 160mm outlets as per EN 1253-2:2015). 

 

The flow rates shown should be used as a guide only. Each drainage area will have individual features that may influence overall flow characteristics. 

Accessories 

Example Specification