Square Gutter

Gutter Supplies square guttering is manufactured by FloPlast, the market leader in the UK. The square gutter system is manufactured to BS EN12200 and carries a 20 year performance and 10 year colour* guarantee. Square gutters have become more popular over the last ten years. The flow rate is slightly higher than that of half round gutters, and the system can be fitted with either round or square downpipe.


  • Attractive rectilinear profile
  • Flow capacity in excess of half tound
  • Pre-fitted gutter seal retaining clip system for fast user-friendly installation
  • Pre-lubricated gutter seals
  • Cost-effective solution for both new build and refurbishment applications
  • Connects to most other metal or plastic systems using our extensive range of adaptors
  • The system is covered by a BSI Kitemark - no. KM501316

* Covers Black, White and Brown

Click here to watch a short video detailing the features and benefits of the Floplast Gutter System


If you are looking to match up with existing square guttering, perhaps on a neighbouring roof, you should establish the make of that system (it will be written on one, if not all, of the fittings), and check the compatibility chart on our technical page - not all square systems are interchangeable.

FloPlast square guttering is compatible with most systems including Hepworth, Brett Martin and Hunter. 


The carrying capacity of any gutter system is determined not only by its size but also by the position of the rainwater downpipes in relation to the gutter and the fall to which it is laid. All gutter systems can actually be fixed level, although we would recommend that a fall of 1:600 is incorporated (this equates to approximately 1 inch in 50 feet or 2.5cm in 15 metres in metric terms).

Floplast square guttering's capacity varies between 1.7 litres per second (fixed level with the outlet at one end) and 3.95 litres per second (fixed at 1:350 with a central outlet). Surprisingly this is almost double that flow rate of half round guttering, and more than ample to cope with the flow from a standard pitch, domestic roof. If you have a very steep pitched roof, or perhaps a much larger than average surface area, we would recommend that you consider fitting either our deepflow gutters or ogee gutters.

If your roof is on a barn or commercial building we recommend that you consider using our 170mm industrial

The size of the downpipe is irrelevant in terms of the system capacity – provided that they are kept free of leaves and debris our downpipes will always have a far greater flow capacity than the gutters that they serve. Square guttering connects to 65mm Square Downpipe as standard, but it can easily be connected to 68mm round downpipe if required by using the RDS2 adaptor


For tips and videos on square plastic gutter installation, compatibility and maintenance please visit our Guides and Tips Section.

If you need any other assistance please do not hesitate to contact us.

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