Secure online checkout

Select a Free Delivery Date*

ISO 9001 Quality Management

Award-winning customer service

01904 757372
Rolawn
Buy One, Get One Half Price on Selected Bulk Bags
*Special Offer* Rolawn Lawn Repair Kit
BluWater Solutions High Strength Retention and Drainage Layer - 20mm
BluWater Solutions High Strength Retention and Drainage Layer - 20mm - Image 2

BluWater Solutions High Strength Retention and Drainage Layer – 20mm

A high-performance 20mm retention and drainage layer with exceptional water storage, drainage and compressive strength.

£23.04£19.20

Available in pallets of 280 units

  • Stores approximately 12 litres of water per m² to support healthy vegetation during dry periods.

  • High compressive strength of up to 40kN/m² provides outstanding structural performance.

  • Promotes effective drainage and ventilation within green roof systems.

  • Interlocking board design creates a stable drainage layer while simplifying installation.

  • Suitable for both extensive and intensive green roof applications.

BluWater Solutions High Strength Retention and Drainage Layer – 20mm is a robust HDPE water management layer designed to maximise drainage, retention and structural performance within green roof systems. Suitable for both extensive and intensive green roofs, the innovative profiled design delivers above-average water retention capacity whilst maintaining excellent drainage performance.

Manufactured from hardened HDPE, the drainage layer stores approximately 12 litres of water per square metre, helping to provide a reliable source of moisture for plants whilst allowing excess rainfall to drain efficiently through the roof build-up. This balance of retention and drainage supports healthier vegetation and improved long-term roof performance.

The system features an integrated interlocking edge design that allows adjacent boards to connect securely, creating a stable drainage layer across the roof surface. Additional surface embossing encourages airflow beneath the overlying filter fleece, supporting root health and enhancing drainage performance during periods of heavy rainfall.

Features

  • Manufactured from hardened HDPE.
  • High-capacity retention and drainage layer.
  • Water storage capacity of approximately 12 litres/m².
  • Suitable for extensive and intensive green roofs.
  • Interlocking board design for enhanced stability.
  • Promotes effective drainage and ventilation.
  • High load-bearing capacity.
  • Fast and straightforward installation.

Material

  • Manufactured from hardened HDPE (High Density Polyethylene).
  • Waterproof construction.
  • Resistant to root penetration.
  • Designed for long-term use within green roof systems.

Performance

  • Water retention capacity: 12 litres/m².
  • Surface load resistance: approximately 400kN/m².
  • Compressive strength with fill: 700kN/m².
  • Water drainage capacity: approximately 12 litres/second/m.
  • Tensile strength: 16kN.
  • Relative elongation at maximum load: 80%.
  • Provides effective ventilation and water movement beneath the growing media layer.

Dimensions

  • Profile height: 20mm.
  • Weight: approximately 1.7kg/m².
  • Board dimensions: 2.05m × 1.05m.
  • Coverage per board: 2.15m².
  • Pallet quantity: 560m².

Durability

  • Design life: 50 years.
  • Ageing durability meets performance requirements.
  • Resistant to commonly encountered roofing conditions.
  • Suitable for long-term green roof installations.

Installation

The innovative interlocking board design enables adjacent panels to connect securely, creating a stable and continuous drainage layer across the roof area. The lightweight format allows for efficient handling and installation while providing consistent drainage and retention performance throughout the system.

Trade and Commercial Customers

Get in touch to discuss your requirements and receive a bespoke quotation for your projects:

Alternatively, you can contact our team on 01904 757372 Monday – Friday, 8.30am – 5pm (excluding Bank Holidays)

Delivery is free of charge on all orders to the majority of UK mainland addresses*; you can select your preferred delivery date for Turf, Handy Bag and Bulk Bag orders in the checkout, before payment. Saturday delivery is available for a set fee of £72 per order (including VAT).

You will receive an email following your order confirmation which will advise you of the delivery method for your delivery address, i.e. ‘Tail lift & manual pallet truck’, or ‘Hiab’.  Further details can be found in our *Delivery Policy.

Please note, in exceptional circumstances, the delivery method stated may not be possible, in which case our Customer Service Team will contact you with an alternative solution.

  • Medallion Turf & Biodiverse Turf: Free delivery is available Tuesday – Friday for most addresses (EH postcodes-only: Monday – Friday). Saturday delivery is available  for a surcharge of £72 per order.*
  • Bulk Bags, Small/Handy Bags & Green Roof Kits: Free delivery dates are available Monday – Friday. Saturday delivery can be selected for a surcharge of £72. If bags are ordered with Turf, the available dates shown in checkout will be Tuesday – Saturday.*
  • Wildflower Turf: Delivery is free of charge Tuesday – Thursday. Saturday delivery is unavailable.* Wildflower Turf will be delivered separately to any other items on the same order.
  • Wildlife Planters, Green Roof Components & Green Roof Kits: Delivery of these products will be within 5-7 working days, Monday – Friday. A free delivery date can be selected at checkout. Slightly longer lead times may be required for planters where colour options have been selected.
  • Grass Seed & Fertiliser: Where these products are ordered with Turf or Bulk Bags we will endeavour to deliver them together, however if purchased separately they will arrive within 2-3 working days via courier, Monday – Friday.

Take a look at our Ordering & Delivery Frequently Asked Questions.

Fuel Surcharge

We have worked hard to mitigate the impact, but due to the current disruption to energy supplies a fuel surcharge of 6.5% will be added to all orders. We appreciate your understanding. Full details can be found in our Delivery Policy.

Further details coming soon…

Feefo Independent Rolawn Reviews

Close
Important update: Temporary 6.5% surcharge effective 7 April 

At Rolawn, we are committed to maintaining the high standards of quality and service our customers expect, so we want to be open with our customers about a change that will affect pricing from Tuesday 7th April. 

This decision has been taken in response to disruption to energy supplies, which has led to significant increases in wholesale prices, affecting not only fuel and fertiliser but also costs throughout our wider supply chain. As a business that relies heavily on fuel for both transport and operations, these sustained cost pressures have become increasingly difficult to absorb.  

While we have worked hard to mitigate the impact, the scale and pace of recent price increases have now exceeded what we can sustain internally, and we therefore need to recover a proportion of these externally driven increases. 

From Tuesday 7th April, a temporary 6.5% surcharge will apply to all products.  

We know that any increase in price is frustrating, particularly at a time when many businesses and households are already feeling under pressure. That is why we want to be clear that this is not a decision we have made lightly, and not one we wanted to make. It has been introduced solely to help offset unavoidable cost inflation and allow us to continue delivering the quality, reliability and service standards associated with Rolawn. 

We will continue to monitor market conditions closely and will review this surcharge as soon as circumstances allow, providing reasonable notice of any changes. We recognise that any price increase is unwelcome, but this step is necessary to ensure the continuity and reliability of our operations during a period of ongoing uncertainty. 

We remain committed to providing the quality, reliability and service standards you expect from Rolawn, and we truly appreciate your understanding and continued support. 

If you have any questions, please contact our customer support team who will be happy to help.