This site uses cookies to store information on your computer. Learn more about these cookies, and how to opt out of them. Find out more

NBS Source

IN1 Intensive Green Roof Substrate

Verified by manufacturer 4 days ago

Boughton Loam

Intensive green roof substrate with a greater proportion of organic matter and finer sand particles.

Jump to:
+44 (0)1536 510515


Suitable for intensive green roof installations; provides a stable growing medium for a wide variety of plants, including green roof lawns, shrubs and trees.

Can be laid to depths varying from 100 to 500 cm. The depth of substrate is determined by the planting scheme and the weight loading capability of the roof, which must be assessed by a qualified structural engineer. At depths above 450/ 500 cm, a lightweight subsoil should be used.


This substrate has a greater organic content to allow it to support larger plants and also to be installed at deeper depths. Its sandy texture means that it can easily be installed at depths from 100 to 500 cm if sufficient weight bearing capacity is available.

This substrate is designed for intensive green roofs, where planting schemes are much more detailed and formalized. This means that a wide range of plants can be supported in IN1, depending on how deep is has been installed.

Depending on the substrate depth and plant type, permanent irrigation systems (above or below ground) are sometimes installed. These are usually to act as a backup for extended dry periods and are not required for every day irrigation as the substrate has the ability to hold onto sufficient moisture during ambient conditions.

Features and benefits:

  • Substrate density:
  • Bulk density when oven dried: 1.07 g/cm³.
  • Bulk density at 10% VMC: 1.33 g/cm³.
  • Bulk density at field capacity: 1.46 g/cm³.
  • Particle density: 2.18 g/cm³.
  • Water and air:
  • Field capacity: 53.9 % v/v.
  • Total porosity: 48.9%.
  • Porosity at field capacity: 57.5%.
  • Effective porosity: 0.0%.
  • Saturated hydraulic conductivity: 18 mm/min.
  • Chemical:
  • Organic matter: 3.7%.
  • pH value: 8.
  • EC: 3.1 mS/cm.
  • Plant available nutrients:
  • Nitrogen: 7.8 mg/L.
  • Phosphate: >165 mg/L.
  • Potassium: >241 mg/L.
  • Particle size distribution:
  • Stones (>8 mm): 10.4%.
  • Coarse gravel (84 mm): 5.0%.
  • Fine gravel (42 mm): 0.6%.
  • Very coarse sand (21 mm): 7.2%.
  • Coarse sand (1.00.5 mm): 20.1%.
  • Medium sand (0.50.25 mm): 39.5%.
  • Fine sand (0.2500.125 mm): 15.5%.
  • Very fine sand (0.1250.050 mm): 1.2%.
  • Silt (0.0500.002 mm): 0.5%.
  • Clay (<0.002 mm): 0.1%.

General information






Pr_45_31_89_35 Green roof substratesPrimary
Pr_45_31_89_41 Imported growing media
Pr_45_31_89_50 Manufactured growing media


Q28/125 Green roof growing media system

Q37/110 Intensive green roof

Specification data - Green roof substrates

General requirements

Topsoil, growing medium, subsoil and preparation materials generally.


Boughton Loam.


Manufacturer standard.


G.R.O Guidelines.

pH (range)


Organic matter content


Percentage of material greater than 4.0 mm in size (by mass)


Percentage of material greater than 8.0 mm in size (by mass)


Maximum water holding capacity (by volume)

Manufacturer standard.

  • Field capacity: 53.9 % v/v.
  • Total porosity: 48.9%.
  • Porosity at field capacity: 57.5%.
  • Effective porosity: 0.0%.
  • Saturated Hydraulic Conductivity (mm min-1): 18

Water permeability

18 mm/min.


Boughton Landscape Product Brochure

Boughton Landscape Product Brochure

Case studies

Lillie Square

Lillie Square

Similar products from Boughton Loam

Boughton Biodiverse Green Roof Substrate

Boughton Biodiverse Green Roof Substrate

EX1 Extensive Green Roof Substrate

EX1 Extensive Green Roof Substrate

Urban Tree Soil

Urban Tree Soil