NBS Source
Newton 409 Root Barrier


Suitable for use as a root barrier to protect the waterproofing membrane from root damage within intrusive green roof systems or planters.


An impermeable high-density polyethylene (HDPE) membrane, providing robust root-proof protection to the primary waterproofing membrane to green roofs or planters where intrusive root systems are present.

The membrane provides an efficient and reliable barrier against Japanese Knotweed and other aggressive root systems.

Consult manufacturer's literature for relevant installation instructions.

Features and benefits:

  • Good chemical and biological resistance.
  • High tensile strength and puncture resistance.
  • Suitable for existing and newly planted trees and plants.
  • Lightweight and durable.
  • Resistant to sea water and fertilizers.
  • Quick and easy to install.

General information




Black high-density polyethylene (HDPE)


1.2 x 50 m (w x l), 1 mm thickness

Uniclass 2015

Pr_25_57_51_66 Polymeric membranesPrimary


Q37/110 Intensive green roof

Q37/320 Root barrier

Q37/355 Combined layers

R12/373 Root barriers

Product range

External Waterproofing and Drainage Membranes

Specification data - Polymeric membranes Enhanced data


To EN ISO 12958, ASTM D1621, BS EN 1931 and to EN 14030/ EN ISO 13438.

Width (minimum)

1200 mm.

Thickness (minimum)

1 mm.



Product Reference

Newton 409 Root Barrier (M32)

Supplied By

Newton Waterproofing.


720 g/m².

Packaged weight

44.00 kg.

Service temperature

-40 to +80 °C.

Water-flow at 20 kPa – 1:80 slope – Upper layer

0.07 L/m/s.

Water-flow at 100 kPa – 1:80 slope – Upper layer

0.04 L/m/s.

Water-flow at 200 kPa – 1:80 slope – Upper layer 0.02 l/m/s EN ISO 12958

0.02 L/m/s.

Compressive strength – Temporary loading

>240 kPa.

Compressive strength – Permanent loading >120 kPa ASTM D1621

>120 kPa.

Water vapour diffusion resistance – Sd value

>604 m.

Water vapour diffusion resistance – µ value >1208000 µ Calculated from SD value

>1 208 000 µ.

Water vapour diffusion resistance

>3020 MNs/g.

CBR puncture resistance

2800.00 N.

Tensile strength (Machine direction)

19 kN/m².

Tensile strength (Cross direction)

10 kN/m².

Chemical resistance


Oxidation resistance



Newton 409 RootBarrier Puncture Resistant Root Barrier Membrane

Newton 409 RootBarrier Puncture Resistant Root Barrier Membrane

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