Green Roof Cobbles and Gravel Margins
Cobbles and pebble gravel form the non-vegetated margins on every well-built green roof. They create a 300 to 500 mm fire break around upstands, parapets and rooflights, give clear access to outlets and rainwater goods, and keep substrate and vegetation back from edge details. Our washed 20 to 40 mm rounded grey cobbles are clean, low-fines and supplied in bulk bags for nationwide pallet delivery.
Washed grey cobbles and pebble gravel margins for green roofs. Fire breaks, perimeter trims and inspection zones around outlets. Supplied UK-wide in bulk bags.
Frequently asked questions
Do I need cobbles around my green roof?
Yes. UK guidance and most insurer specifications require a 300 to 500 mm non-vegetated gravel or cobble margin around upstands, parapets, rooflights and outlets. It acts as a fire break, an inspection path and a clean edge between vegetation and roof trims.
What size cobbles are best for a green roof?
Washed 20 to 40 mm rounded cobbles are the standard size. They are heavy enough to stay in place, large enough not to wash into drainage outlets and small enough to walk on for maintenance.
How much do green roof cobbles cost?
Pricing depends on bag quantity and delivery postcode. Tell us your perimeter length and margin width and we will calculate the bags needed and send a fixed supply quote.
About The Green Roofer
The Green Roofer designs, supplies and installs green roofs for homes, developers and commercial buildings across the UK, with strong coverage in Essex, Southend-on-Sea, Chelmsford and London. We work on everything from a single garden shed or extension to large commercial flat roofs. See our residential green roof services or our commercial roofing services.
Our systems include sedum roofs, biodiverse and wildflower roofs, intensive roof gardens, blue roofs for stormwater attenuation and bio-solar roofs that combine planting with solar panels. Smaller projects are welcome too, including a green roof for your shed. We also supply green roof materials UK-wide for trade customers and DIY projects: complete systems such as the certified sedum green roof system, traditional green roof system, biodiverse green roof system and lightweight biodiverse system, plus individual components including sedum mats, wildflower mats, green roof substrate, drainage board, filter fleece, protection fleece and decorative cobbles.
Every project starts with a free site survey and a clear, no-obligation quote. We check roof structure, load capacity, waterproofing and drainage before recommending a system, and we offer ongoing green roof maintenance so the planting stays healthy year after year. Green roofs help manage rainwater, improve insulation, extend the life of the waterproofing beneath them and support biodiversity, including Biodiversity Net Gain requirements on new developments.
Planning a project? Read our guide to green roof planning permission. For commercial buildings we also supply and fit rainwater hoppers and roof flashings and trims.
Call 01702 964002 or email hello@thegreenroofer.co.uk for a free, no-obligation quote.