112mm Half Round Rainwater System
Technical Data Sheet
Document Reference: TDS-RW-HR-001
Issue Date: August 2026
System: 112mm Half Round with 68mm Round Downpipe
Product Description
The Kalsi 112mm Half Round rainwater system is a traditional semi-circular profile gutter with matching 68mm round downpipes. This classic design suits virtually any UK property type and remains one of the most popular profiles nationwide. Manufactured from high-quality PVC-U with co-extruded UV-stabilised outer layer for lasting colour retention.
System Dimensions
Gutter
| Dimension | Value | Tolerance |
|---|---|---|
| Profile width (top) | 112mm | ±1mm |
| Profile depth | 55mm | ±1mm |
| Wall thickness | 2.0mm | ±0.2mm |
| Available lengths | 2m, 4m, 5m | ±5mm |
| Weight | 0.54 kg/m | - |
Downpipe
| Dimension | Value | Tolerance |
|---|---|---|
| External diameter | 68mm | ±0.5mm |
| Internal diameter | 61.4mm | ±0.5mm |
| Wall thickness | 3.3mm | ±0.2mm |
| Available lengths | 2.5m, 2.75m, 4m, 5.5m | ±5mm |
| Weight | 0.58 kg/m | - |
Hydraulic Performance
Gutter Flow Capacity
| Gradient | Outlet Position | Flow Rate |
|---|---|---|
| 1:600 | End outlet | 1.52 L/s |
| 1:350 | End outlet | 1.85 L/s |
| Level | Centre outlet | 2.40 L/s |
Downpipe Capacity
| Condition | Flow Rate |
|---|---|
| Full bore | 3.10 L/s |
| 1/3 full (typical) | 1.55 L/s |
Maximum Effective Roof Area
| Rainfall Intensity | Max Roof Area |
|---|---|
| 75mm/hr (standard) | 114m² |
| 100mm/hr (exposed) | 86m² |
| 150mm/hr (high exposure) | 57m² |
Material Specification
| Property | Specification |
|---|---|
| Material | PVC-U (unplasticised polyvinyl chloride) |
| Product standard | Confirm the current declaration and testing scope with Kalsi Technical |
| Formulation | Lead-free, cadmium-free |
| UV stabilisation | Co-extruded cap layer |
| Colour through | Full body colour |
| Chemical resistance | Resistant to dilute acids/alkalis |
Physical Properties
| Property | Value | Test Method |
|---|---|---|
| Tensile strength | ≥45 MPa | BS EN ISO 527 |
| Impact resistance (23°C) | No fracture | Current test declaration available on request |
| Impact resistance (-10°C) | No fracture | Current test declaration available on request |
| Vicat softening temperature | ≥76°C | BS EN ISO 306 |
| Coefficient of expansion | 0.06 mm/m/°C | - |
Colour Options
| Colour | Part Code Suffix | Availability |
|---|---|---|
| White | W | Standard stock |
| Black | BL | Standard stock |
| Brown | BR | Standard stock |
| Grey | G | Standard stock |
| Anthracite Grey | AG | Made to order |
Colours matched across gutter and downpipe components.
Product Range Summary
Gutters
| Description | Part Code | Pack Qty |
|---|---|---|
| 112mm Half Round Gutter 2m | AG2* | 6 |
| 112mm Half Round Gutter 4m | AG4* | 6 |
| 112mm Half Round Gutter 5m | AG5* | 6 |
Angles
| Description | Part Code | Angle | Pack Qty |
|---|---|---|---|
| 90° Gutter Angle | AA1* | 90° | 20 |
| 120° Gutter Angle | AA3* | 120° | 20 |
| 135° Gutter Angle | AA2* | 135° | 20 |
| 150° Gutter Angle | AA4* | 150° | 20 |
Stop Ends
| Description | Part Code | Pack Qty |
|---|---|---|
| External Stop End | AE1* | 100 |
| Internal Stop End | AE2* | 100 |
Outlets
| Description | Part Code | Pack Qty |
|---|---|---|
| Running Outlet | AO1* | 20 |
| Stop End Outlet | AO2* | 20 |
Brackets
| Description | Part Code | Pack Qty |
|---|---|---|
| Fascia Bracket | AK1* | 100 |
| Union Bracket | AU1* | 30 |
| Rise and Fall Bracket | RF/HALF | 1 |
Downpipes
| Description | Part Code | Length | Pack Qty |
|---|---|---|---|
| 68mm Round Downpipe | AP2.5* | 2.5m | 6 |
| 68mm Round Downpipe | AP2.75* | 2.75m | 6 |
| 68mm Round Downpipe | AP4* | 4m | 6 |
| 68mm Round Downpipe | AP5.5* | 5.5m | 6 |
Downpipe Fittings
| Description | Part Code | Spec | Pack Qty |
|---|---|---|---|
| 92.5° Offset Bend | AB1* | 92.5° | 30 |
| 112.5° Offset Bend | AB2* | 112.5° | 30 |
| Pipe Shoe | AB3* | - | 30 |
| Pipe Clip | AC1* | - | 100 |
| Pipe Socket | AS1* | - | 50 |
| Branch 112.5° | AY1* | 112.5° | 20 |
| Hopper | AHS1* | - | 10 |
Adaptors
| Description | Part Code | Pack Qty |
|---|---|---|
| Square/Round Gutter Adaptor | ADS1* | 30 |
| Square to 68mm Round Adaptor | ADS2* | 50 |
| 68mm to 110mm Soil Adaptor | ADS6* | 50 |
Accessories
| Description | Part Code | Pack Qty |
|---|---|---|
| Eaves Protector 1.5m | K/HDEP | 10 |
| Gutter Guard 0.5m | GGUA | 10 |
| Drain Guard | ADGBL | 30 |
Replace * with colour suffix: BL (Black), BR (Brown), W (White), G (Grey), AG (Anthracite Grey)
Installation Guidelines
Gutter Installation
- Maximum fascia bracket spacing: 600mm
- Heavy snow or extreme weather conditions: 300mm maximum
- Near joints/fittings: Within 150mm
- Minimum fall: 1:600 (1.5mm per metre)
- Recommended fall: 1:350 (3mm per metre)
- Expansion gap: 10mm at union joints
Downpipe Installation
- Maximum clip spacing: 1800mm (1500mm recommended)
- Near bends/joints: Within 150mm of fitting
- Wall clearance: Minimum 25mm
Thermal Movement
- Allow 6mm expansion per 4m length per 20°C temperature change
- Always use union brackets with expansion gaps
- Do not over-tighten clips
Standards Compliance
- Current standards, declarations and certification scope are available from Kalsi Technical
- ✓ Lead-free and cadmium-free formulation
- ✓ ISO 9001:2015 manufactured
- ✓ 100% UK manufactured
Guarantee
Rainwater Guarantee: Coloured: 5 years | Cast effect: 10 years | White: 15 years. Full written terms apply.
Registration does not extend rainwater cover unless Kalsi confirms this in writing before purchase.
Technical Support
Kalsi Plastics Ltd
Tomey Road, Tyseley
Birmingham B11 2LL
Technical Helpline: [TBC]
Email: info@kalsiplastics.co.uk
Web: www.kalsiplastics.co.uk
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