Aquaflow
The UK's complete plastic drainage brand. Rainwater systems, underground drainage, and soil & waste — all manufactured in Birmingham to the highest standards.
Designed and manufactured in the UK — Kalsi is a verified Made in Britain manufacturer
30+ Years of Drainage Expertise
Aquaflow is Kalsi Plastics' drainage brand — covering everything from the gutter at the roofline to the pipe beneath the ground. Aquaflow products are manufactured at our Birmingham facility, compounded in-house and subject to documented quality controls. Current declarations and certification scope are available for applicable products. When you specify Aquaflow, you have a direct line back to the manufacturer.
Three Complete Drainage Systems
12 Systems Rainwater Systems
12 gutter and downpipe systems — from domestic half round to high-capacity commercial profiles. Technical data and current colour-specific guarantee terms are available from Kalsi.
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Kitemark Certified Underground Drainage
110mm and 160mm Kitemark certified systems for domestic and commercial foul and surface water drainage. BBA certified 50+ year service life.
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3 Jointing Systems Soil & Waste
Three jointing options — push-fit, solvent weld, and ring seal. 32mm to 160mm. Complete above-ground drainage solution for residential and commercial.
View RangeAvailable in 6 Colours
Colour availability varies by system. Routine inspection and cleaning are recommended for all external rainwater products.
Built to Last. Backed by British Manufacturing.
Quality Controlled
Manufactured under documented production and inspection controls.
Technical Documentation
Current product data, declarations and certification scope available on request.
UV Stabilised
PVC-U material and finishes designed for external rainwater applications.
Written Guarantee Terms
Cover varies by product and colour; request the current terms before purchase.
UK Manufactured
100% produced in Birmingham — consistent quality, reliable supply.
Direct Technical Support
Specification and installation support direct from the manufacturer.
Specify with Confidence
Free technical tools to help you calculate the right Aquaflow system for your project.
Rainwater Flow Calculator
Calculate required gutter capacity to BS EN 12056-3. Enter roof area and rainfall intensity to find the right system.
Open CalculatorDrainage Flow Calculator
Select the right underground drainage pipe size using the Colebrook-White equation. 110mm or 160mm?
Open CalculatorSpecify Aquaflow on Your Next Project
Talk to our technical team about the right Aquaflow system for your application — domestic or commercial, above ground or below.