Rainwater Systems Ref: TDS-RW-HC-001

Hi-Cap Rainwater System

Technical Data Sheet

Hi-Cap Rainwater System

Technical Data Sheet

Document Reference: TDS-RW-HC-001
Issue Date: February 2026
System: 145mm Hi-Cap with 82mm Round Downpipe


Product Description

The Kalsi Hi-Cap rainwater system provides high-capacity water management for commercial and larger residential applications. The robust half-round profile handles significant water volumes from larger roof areas, making it ideal for industrial buildings, warehouses, agricultural structures, and commercial developments where drainage capacity is critical.


System Dimensions

Gutter

DimensionValueTolerance
Profile width (top)145mm±1mm
Profile depth75mm±1mm
Wall thickness2.5mm±0.2mm
Available lengths4m±5mm
Weight0.98 kg/m-

Downpipe

DimensionValueTolerance
External diameter82mm±0.5mm
Internal diameter74mm±0.5mm
Wall thickness4.0mm±0.2mm
Available lengths4m, 5.5m±5mm
Weight0.82 kg/m-

Hydraulic Performance

Gutter Flow Capacity

GradientOutlet PositionFlow Rate
1:600End outlet3.10 L/s
1:350End outlet3.70 L/s
LevelCentre outlet5.50 L/s

Downpipe Capacity

ConditionFlow Rate
Full bore5.80 L/s
1/3 full2.90 L/s

Maximum Effective Roof Area

Rainfall IntensityMax Roof Area
75mm/hr (standard)260m²
100mm/hr (exposed)195m²
150mm/hr (high exposure)130m²

Material Specification

PropertySpecification
MaterialPVC-U (unplasticised polyvinyl chloride)
StandardBS EN 607:2004
FormulationLead-free, cadmium-free
UV stabilisationCo-extruded cap layer

Colour Options

ColourPart Code SuffixAvailability
BlackBLStandard stock
GreyGStandard stock

Product Range Summary

Gutters

DescriptionPart CodePack Qty
145mm Hi-Cap Gutter 4mHCG4*4

Angles

DescriptionPart CodeAnglePack Qty
90° Gutter AngleHCA90*90°15
135° Gutter AngleHCA135*135°15

Stop Ends & Outlets

DescriptionPart CodePack Qty
External Stop EndHCE1*40
Internal Stop EndHCE2*40
Running OutletHCO1*15

Brackets

DescriptionPart CodePack Qty
Fascia BracketHCK1*50
Union BracketHCU1*25

Downpipes

DescriptionPart CodeLengthPack Qty
82mm Round DownpipeHCP4*4m4
82mm Round DownpipeHCP5.5*5.5m4

Downpipe Fittings

DescriptionPart CodePack Qty
92.5° Offset BendHCB1*25
112.5° Offset BendHCB2*25
Pipe ShoeHCB3*25
Pipe ClipHCC1*50
Pipe SocketHCS1*30

Applications

Ideal For

  • Industrial units and warehouses
  • Agricultural buildings
  • Large commercial properties
  • Sports facilities
  • School buildings
  • Shopping centres
  • Multi-storey car parks

Key Considerations

  • Calculate roof area carefully for commercial installations
  • Consider multiple outlets for very large roof areas
  • May require larger underground drainage connection

Installation Guidelines

Gutter Installation

  • Maximum bracket spacing: 800mm
  • Near joints/fittings: Within 150mm
  • Minimum fall: 1:600
  • Expansion gap: 12mm at union joints

Structural Requirements

  • Ensure fascia/mounting structure can support loaded weight
  • Consider wind loading for exposed commercial installations
  • May require additional support for long runs

Standards Compliance

  • ✓ BS EN 607:2004
  • ✓ BSI Kitemark certified
  • ✓ Lead-free formulation
  • ✓ ISO 9001:2015 manufactured
  • ✓ UK manufactured

Guarantee

Product Guarantee: 10 years against manufacturing defects


© Kalsi Plastics Ltd. All rights reserved.