Green roofs
Accessories
Wallbarn has a number of accessories to compliment any green roof installation whether this be for our Modular System ( M-Tray® ) or rollout system.
These accessories are used on both these systems and our team is happy to assist you in selecting the appropriate product for your project, ensuring compliance with the latest regulations.

Edge Trim
Our Aluminium Edge Trim is versatile and can be used in various ways depending on the green roof system you are installing. It enhances the exterior aesthetic of any system and is essential for containing pebble borders when there is no parapet or raised upstand.
In rollout systems, it effectively separates vegetation from areas like pebble borders, drains, and roof lights. The trim’s right-angled aluminium profile fits neatly against the deck, allowing it to sit underneath and be secured by the weight of either the M-Trays® or additional pebbles.

Pebbles
Building regulations and the GRO Code require the installation of a pebble border around the perimeter of a green roof and around features such as roof lights and drainage outlets to act as a fire break.
We recommend using clean, rounded river stone pebbles that are free from foreign materials and dirt. Wallbarn supplies these pebbles in large 1-tonne bulk bags or more manageable 25kg single bags, facilitating easy transportation to the roof.
Our technical team is on hand to provide advice and estimate the quantity needed for your project.

Geotextile
Wallbarn supplies a wide range of geotextile fabrics designed for filtration, separation and protection in green roof systems. Geotextile is the first layer applied on a green roof, protecting the waterproofing membrane while allowing water to pass through and trapping fine particles. It can also be placed above the drainage board as a filtration layer in roll-out green roof systems.
Our standard option is the PECT 300 GSM, a reliable separation and filtration layer. We also offer additional alternatives in line with GRO Code guidance:
- Recycled Polypropylene PPT 400 GSM
- Recycled Polypropylene PPT 500 GSM
- High Tenacity Virgin Polypropylene PPST 150 GSM
These geotextiles exceed the GRO Code requirements for tensile strength and puncture resistance, ensuring long-term performance and protection.
Geotextile is always included in Wallbarn green roof orders, but it can also be purchased separately. To discuss your project or place an order, contact our team.

Fertiliser
Sedum green roofs are notably resilient, and most all-purpose fertilisers are suitable for their upkeep. However, we highly recommend the Vitax Q4 natural and organic fertiliser, available from Wallbarn.
This all-purpose fertiliser is enriched with mycorrhizal fungi, helpful bacteria, and biostimulants, all of which significantly enhance rapid root growth and establishment.

Inspection Box
The JacBox (inspection box) is crafted from powder-coated aluminium, ensuring corrosion resistance and offering a range of colour options.
It is readily available and in stock with a black powder-coated finish, and comes with bases either 50mm or 300mm high in a full-slot design, suitable for standard or parapet applications. The slots are designed to allow the free flow of rainwater.
With various extension components, you can achieve any required depth of roofing buildup. Interlocking mid-sections are available in four different sizes, enabling multiple build-up heights. These sections are lightweight, easy to assemble, and quick to install.
The boxes can be powder-coated to match any RAL colour required. Additionally, the lid is lockable to enhance security.

Gravel Excluders
Our gravel excluders, available in plastic, are designed for use in circular drain connectors and roof outlets where the area is covered with a gravel or pebble layer, such as border edges or shingle ballast in an inverted roof system.
Constructed from polypropylene, these excluders feature a sturdy cage on the top, strong sidebars, and slats to allow water to drain through.
We offer two main designs: the Helix spoke, which includes three wide spokes, and the Spider fitting, featuring an angled four-spoke design. Both designs enable installers to easily trim the spokes with a sharp knife to fit the diameter of the outlet holes perfectly.
The Sombra gravel excluder is an ideal cover for outlets with a diameter of up to 180mm and is particularly suitable for use on green roofs, accommodating pebble heights up to 150mm.
Installation Guide
Technical Datasheets
- Geotextile PECT 300 GSM
- Geotextile PPST 150 GSM
- Geotextile PPT 400 GSM
- Geotextile PPT 500 GSM
- Aluminium Edge Guard
- Inspection Chamber
- Pebbles for Green Roofs
- VITAX Fertiliser for Green Roofs
- Datasheet – Rectangular Gravel & Leaf Guard
- Datasheet – Universal Leaf Guard – Polypropylene
- Datasheet – Sombra Gravel Excluder
- Datasheet – Spider Gravel Excluder
- Datasheet – Helix Gravel Excluder