Dimond Box 300 Commercial Gutter

Dimond Box 300 Gutter

Suitable for light commercial

Suitable for commercial

Box 300 Gutter is manufactured in Hamilton and Christchurch.

If this product is not suitable for your project... Click here to find product options suitable for your requirements.

Dimond Box 300 Gutter Profile

Large sized square gutter for commercial and industrial applications

Dimond Box 300 Gutter Profile

Dimond Box 300 Gutter Profile Dimensions

all dimensions given are nominal

Effective cross sectional area (with 15mm free board)


Flow capacity

727 litres/min

Minimum recommended fall

1:500 (2mm in 1m)

Minimum downpipe - Circular


Minimum downpipe - Rectangular

min. cross sectional area of 18,500mm²

Catchment area per downpipe based on the above flow capacity is given in the table below.

Rainfall Intensity (mm/hr) 40 50 60 70 80 90 100 120 140 160 180 200
Catchment Area per downpipe (m²) 1090 870 725 620 545 485 435 360 310 270 240 215

Material options including thickness and grade


0.55mm G300


0.90mm H34


0.55mm 1/2 hard

Stainless steel

refer Dimond

Roll-forming facility

Hamilton (dimensions may vary slightly, please check with your local Dimond branch)

Bracket Material Thickness
External Hot dipped galvanised 5mm x 50mm
External Aluminium 6mm x 38mm
External Stainless steel 5mm x 40mm

Recommended bracket maximum spacings

Steel - 600mm (refer snow bracket instructions for spacings where snow fall is possible)

Aluminium - 450mm internal, 600mm external

Recommended fixings

Bolt, screw or nail fastenings to be compatible with substrate and bracket material

Scope of Use

Dimond Rainwater Disposal Systems are intended to collect and channel water that runs off a roof. It is intended that the metal gutters be placed at the perimeter of the building, and not in an internal situation.
Use of the products is subject to the limitations listed below.


Attention to the following details is required to ensure the expected system performance is achieved.

  • The selection of the type and grade of gutter and bracket material and fasteners must be based on the life expectancy required and the severity of the external and internal environments. Refer Sections,,, 2.2.3 of Roofing & Cladding Technical Manual.
  • Site storage that keeps the product dry and protected from damage.
  • Product handling that prevents surface damage.
  • Correct installation of the brackets and gutter.
  • Allowance for thermal expansion and contraction.
  • Sufficient fall to permit complete surface water drainage, allowing the gutter to completely dry out and not hold water.
  • Control of allowable contact with dissimilar materials. Refer Section of Roofing & Cladding Technical Manual.
  • Awareness and implementation of maintenance requirements, particularly for surfaces not washed by natural rainfall. Refer Section Roofing & Cladding Technical Manual.

NZBC Compliance

Test information available from Pacific Coil Coaters and BHP NZ Steel, and past history of rainwater products, indicate that provided the product use and maintenance is in line with the guidelines contained in the current literature referenced, Dimond Rainwater Disposal Systems can be expected to meet the performance criteria in Clause E2 of the New Zealand Building Code, for a period of not less than 5 years.

Use Outside the Stated Guidelines

If the need arises to use Dimond Rainwater Disposal Systems outside the limitations and procedures given in this or other referenced literature, or, if any doubt exists on product handling or use, written approval for use must be obtained from Dimond, before the project commences.

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