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Rainwater Gutter Compatibility Guide
Choosing the right gutter system — and knowing which manufacturers’ fittings work together — saves time, money, and prevents leaks. Use this guide to pick the best system for your project and order with confidence.
10 Manufacturers
Avoid Costly Mistakes
Which Gutter System Do I Need?
Five systems to suit every property — from standard residential homes to large commercial buildings. Choose based on your roof size, rainfall, and aesthetic preference.
Most Popular
112mm Half Round
Standard residential homes, extensions, garages
Square Line
Modern properties, clean geometric lines
High Capacity
Deep Flow
Heavy rainfall areas, larger roofs
Exclusive
Krown Ogee
Decorative properties, period homes
Commercial
150mm Kommercial
Commercial, agricultural, large builds
Cross-Manufacturer Compatibility Chart
Not all brands’ fittings are interchangeable. Use this chart to check which manufacturers’ guttering and fittings are compatible with Aquaflow systems.
Scroll sideways to see all systems
| Manufacturer | 112mm Half Round | Square Line | Deep Flow | Krown Ogee | 150mm Kommercial |
|---|---|---|---|---|---|
| Brett Martin | ✓ | ✗ | ✓ | ✗ | ✗ |
| FloPlast | ✓ | ✓ | ✓ | ✗ | ✗ |
| Freeflow | ✓ | ✓ | ✓ | ✗ | ✗ |
| Geberit Terrain | ✗ | ✗ | ✗ | ✗ | ✗ |
| Hepworth | ✓ | ✓ | ✓ | ✗ | ✓ |
| Hunter | ✓ | ✓ | ✓ | ✗ | ✗ |
| Marley | ✓ | ✗ | ✓ | ✗ | ✓ |
| Marshall Tufflex | ✓ | ✓ | ✓ | ✗ | ✗ |
| Osma (Wavin) | ✓ | ✗ | ✓ | ✗ | ✓ |
| Polypipe | ✓ | ✓ | ✓ | ✗ | ✓ |
Krown Ogee is exclusive to Aquaflow and is NOT compatible with any other manufacturer’s fittings. Only use Aquaflow Krown Ogee fittings with Aquaflow Krown Ogee guttering. Do not attempt to mix with Klassic Ogee, Marshall Tufflex Ogee, or any other ogee-style system.
Geberit Terrain uses a proprietary system not compatible with any standard UK plastic guttering profiles. If you have Geberit Terrain guttering, you must use Geberit Terrain fittings only.
Flow Capacity Comparison
Choose your system based on the water volume you need to handle. Higher capacity = better protection against heavy rainfall.
| System | Gutter Level | 1:350 Gradient |
|---|---|---|
| 112mm Half Round | ||
| Square Line | ||
| Deep Flow | ||
| Krown Ogee | ||
| 150mm Kommercial |
Flow capacity measured to BS EN 12056-3. “1:350 Gradient” means the gutter falls 1mm for every 350mm of length — the standard recommended installation gradient.
System-by-System Breakdown
112mm Half Round Guttering
The UK’s Standard Residential Gutter
The 112mm half round gutter is the most widely used system in the UK. Its classic curved profile suits the vast majority of residential properties and is the go-to choice for new builds, extensions, garages, conservatories and replacement projects.
At 1.90 L/s when fitted level, it handles the drainage needs of most standard roofs comfortably. Fittings are widely available and cross-compatible with the majority of major UK manufacturers, making it the easiest system to source parts for.
Compatible Manufacturers
Key Products in This System
- 112mm Half Round Gutter (3m & 4m lengths)
- 112mm Union Bracket
- 112mm Fascia Bracket
- 112mm Running Outlet
- 112mm Stop End (internal & external)
- 112mm 90° & 135° Angles
- 68mm Round Downpipe (2.5m, 4m & 5.5m)
- 68mm Pipe Clip & Pipe Shoe
- 68mm Pipe Branch
Square Line Guttering
Modern Profile, Greater Capacity
Square Line guttering offers a clean, contemporary aesthetic with its flat-fronted profile. It’s particularly popular on modern builds and properties where a sharp, geometric roofline is preferred.
With a flow capacity of 2.20 L/s when level (16% more than half round), Square Line provides a good balance of style and performance. It’s compatible with several major brands, though not as universally cross-compatible as half round.
Compatible Manufacturers
Key Products in This System
- 114mm Square Gutter (3m & 4m lengths)
- 114mm Square Fascia Bracket
- 114mm Square Union Bracket
- 114mm Square Running Outlet
- 114mm Square Stop End (left & right)
- 114mm Square 90° & 135° Angles
- 65mm Square Downpipe (2.5m & 4m)
- 65mm Square Pipe Clip & Pipe Shoe
- Square to Round Downpipe Adaptor
Deep Flow Guttering
High Capacity for Heavy Rainfall
Deep Flow (also known as high-capacity half round) uses the same classic half round profile but is wider and deeper at 120mm, delivering double the flow capacity of standard 112mm guttering — 3.80 L/s when level.
This system is the smart upgrade for properties in high-rainfall areas, homes with large or steeply pitched roofs, and situations where standard half round just can’t cope. It’s widely cross-compatible with the same brands as half round.
Compatible Manufacturers
Key Products in This System
- 120mm Deep Flow Gutter (3m & 4m lengths)
- 120mm Deep Flow Fascia Bracket
- 120mm Deep Flow Union Bracket
- 120mm Deep Flow Running Outlet
- 120mm Deep Flow Stop End (internal & external)
- 120mm Deep Flow 90° & 135° Angles
- 68mm Round Downpipe (shared with Half Round)
- 68mm Pipe Clip & Pipe Shoe
Krown Ogee Guttering
Decorative Style Meets High Performance
Krown Ogee features an elegant double-curved (OG) profile that adds a premium decorative finish to any property. It’s the top choice for period homes, heritage restorations, and any project where visual appeal is a priority alongside drainage performance.
With 3.77 L/s flow capacity when level, it matches Deep Flow for performance. However, Krown Ogee is an Aquaflow-exclusive system — no other manufacturer makes compatible fittings. You must use Aquaflow Krown Ogee components throughout.
Krown Ogee is NOT the same as Klassic Ogee. The two systems are not interchangeable. Always confirm you are ordering Krown Ogee fittings specifically.
Compatible Manufacturers
Key Products in This System
- Krown Ogee Gutter (3m & 4m lengths)
- Krown Ogee Fascia Bracket
- Krown Ogee Union Bracket
- Krown Ogee Running Outlet
- Krown Ogee Stop End (left & right)
- Krown Ogee 90° & 135° Angles
- Krown Ogee Downpipe (2.5m & 4m)
- Krown Ogee Pipe Clip & Pipe Shoe
150mm Kommercial Guttering
Maximum Capacity for Large Buildings
The 150mm Kommercial system is engineered for buildings that demand the highest flow capacity — commercial properties, warehouses, large residential developments, agricultural buildings, and any structure with a substantial roof area.
At 4.60 L/s level (6.00 L/s at 1:350 gradient), it’s the most capable system in the range. Despite its commercial focus, it’s available in the same easy-to-install uPVC as the residential systems, and is compatible with several major brands.
Compatible Manufacturers
Key Products in This System
- 150mm Kommercial Gutter (3m & 4m lengths)
- 150mm Kommercial Fascia Bracket
- 150mm Kommercial Union Bracket
- 150mm Kommercial Running Outlet
- 150mm Kommercial Stop End (internal & external)
- 150mm Kommercial 90° & 135° Angles
- 110mm Round Downpipe
- 110mm Pipe Clip & Pipe Shoe
Frequently Asked Questions
Got questions about gutter compatibility? We’ve answered the most common ones below.
No — never mix different gutter profiles. Each gutter system (Half Round, Square Line, Deep Flow, Krown Ogee, Kommercial) has a unique profile shape and specific dimensions. Attempting to connect a Square Line fitting to a Half Round gutter, for example, will result in poor fitment, leaks, and potential system failure.
Always use the same system type throughout your entire installation. If you need to upgrade capacity, replace the full run — don’t try to splice two different profiles together.
It depends on the system. For 112mm Half Round and Deep Flow, most major UK manufacturers’ fittings are cross-compatible — including FloPlast, Polypipe, Hunter, Marley, and others. This is because these systems follow standard BS EN dimensions.
For Square Line, compatibility is more limited — check the chart above. For Krown Ogee, the answer is firmly no — it is an Aquaflow-exclusive system with no third-party compatibility whatsoever.
150mm Kommercial has the highest flow capacity at 4.60 L/s when fitted level, rising to 6.00 L/s at a 1:350 gradient. It’s designed for commercial buildings, large developments, and properties with very large roof areas.
For residential properties needing more capacity than standard, Deep Flow (3.80 L/s) or Krown Ogee (3.77 L/s) offer excellent high-capacity alternatives without needing to step up to a commercial system.
Both use the same classic half-round (curved) profile shape, but they differ in size and capacity:
- 112mm Half Round — 112mm wide, 1.90 L/s flow capacity. The standard residential gutter for most UK homes.
- Deep Flow — 120mm wide and deeper, 3.80 L/s flow capacity. Exactly double the capacity of standard half round.
Deep Flow is the right upgrade when you’re experiencing overflow with standard half round, or when installing on a larger roof or in an area prone to heavy rainfall. The fittings are cross-compatible with the same manufacturers as half round.
Both are ogee-profile gutters with an elegant curved design, but they are completely different systems and are not interchangeable.
- Klassic Ogee — Traditional ogee profile, compatible with some other manufacturers’ ogee systems.
- Krown Ogee — A modern ogee design exclusive to Aquaflow with higher capacity. Not compatible with any other brand or system.
Always double-check which ogee system you’re ordering for. If unsure, call us on 0121 227 5093 and we’ll help you identify the right one.
Look at the gutter profile from the end:
- Curved (U-shaped) — Half Round or Deep Flow. Measure the width: 112mm = Half Round, 120mm = Deep Flow.
- Flat front, square — Square Line.
- S-shaped / double curve — Ogee. Check for branding on the inside to identify Krown vs Klassic.
- Very large curved gutter (150mm+) — Likely Kommercial.
If you’re still unsure, bring a sample piece into your nearest Plastic Centre branch and we’ll identify it for you.
Need help choosing the right system?