EX1 Extensive Green Roof Substrate

Composed of recycled unused crushed brick and PAS 100 compost. EX1 is designed to be free draining, porous and lightweight. Due to its structure, this substrate is best suited to extensive green roof applications and should be installed at a depth of 80–150 mm. The substrate can be installed at depths greater than 150 mm, but other substrates (SemIN2 and IN1) are more suited for this application.

The green roof substrate is especially suited for drought tolerant planting schemes, with Sedum mixes suitable between 80 and 150 mm and wildflower mixes between 120 and 150 mm. Due to its free draining nature, temporary irrigation may be needed to help plants establish during certain times of the year.

Due to the plant communities planted into this substrate, irrigation is generally not required on installations with this substrate. Boughton Loam can provide additional advice if needed on how best to specific and install this substrate.

Features and benefits:

• Substrate density:
• Bulk density when oven dried: 0.83 g/cm³.
• Bulk density at 10% VMC: 0.97 g/cm³.
• Bulk density at field capacity: 1.26 g/cm³.
• Particle density: 1.79 g/cm³.
• Water and air:
• Field capacity: 37.6% v/v.
• Total porosity: 46.4%.
• Porosity at field capacity: 31.3%.
• Effective porosity: 15.1%.
• Saturated hydraulic conductivity: 48 mm/min.
• Chemical:
• Organic matter: 2.8%.
• pH: 7.7.
• Plant available nutrients:
• Nitrogen: 13.1 mg/L.
• Phosphate: >165 mg/L.
• Potassium: >241 mg/L.
• Particle size distribution:
• Stones (>8 mm): 61.2%.
• Coarse gravel (8–4 mm): 28.5%.
• Fine gravel (4–2 mm): 1.2%.
• Very coarse sand (2–1 mm): 0.5%.
• Coarse sand (1.0–0.5 mm): 0.6%.
• Medium sand (0.5–0.25 mm): 1.3%.
• Fine sand (0.250–0.125 mm): 1.2%.
• Very fine sand (0.125–0.050 mm): 0.7%.
• Silt (0.050–0.002 mm): 2.7%.
• Clay (<0.002 mm): 2.0%.