Commercial Client’s Roof Garden

Upgrading a well-known client’s roof garden space

The recycled plastic planters contained a liner with drainage holes in the base. The bottom third of the containers were filled with a terracotta 8-16mm. LECA (lightweight expanded clay aggregate) an inert, bulky material with moisture retaining qualities.

A landscape membrane was installed over this to separate the LECA from the compost above. The lightweight planting medium was a blend of sandy loam, coir, PAS100 Green compost and LECA. All the planting was 10-30 L. pot grown for instant effect.

• The loam itself complies with BS 3882(2015) and is screened to 10mm.
• The Coir is ground coconut husk from Sri Lanka (Peat substitute).
• PAS100 Green compost (Publicly Available Specification) – industry standard for organic material, screened to 10mm, adding nutrients to the mix.
• LECA 4-10mm. is incorporated into the compost to reduce bulk density and enhance drainage characteristics.
• A mulch layer of terracotta LECA completed the project, providing an ornamental finish with moisture retaining properties.
• An irrigation system ensures that the planting receives adequate moisture throughout.

The gallery below shows the planters and a section of the completed commercial roof garden space