ProtectaWeb tree root protection installation guide

ProtectaWeb Tree Root Protection System is available in 4 different depths for various traffic loadings. Each site should have a detailed design to ensure the correct product depth is used.

However, unless the existing ground conditions contain very weak soils and have a low CBR the following can apply:

The guide below is based on soils with a CBR of 3 or above

• 75mm - For pedestrians and cycleways
• 100mm - For cars, 4-wheel drive vehicles, vans, etc. up to 6 tons.
• 150mm - For access roads to be used by light construction traffic.
• 200mm - For loaded HGV's delivering construction materials, cranes, pilling rigs

Material list

• ProtectaWeb 3-Dimensional Cellular Confinement System
• MultiTrack SNW 40 UV minimum separation and protection fleece
• MultiTrack 1000 minimum separation geotextile
• Steel 700mm 'J Hooks' available in 500mm (suitable for ProtectaWeb 75mm, 100mm & 150mm) & 700mm (suitable for 200mm ProtectaWeb)
• Stapler and Staples/heavy cable ties
• 20/40mm or 4/20mm clean Angular Stone to BS EN 13242

• In most circumstances, it is acceptable to remove up to 50mm of surface organic material, including leaf litter and low vegetation, to establish a suitable working platform. However, if surface roots are present, or where the topsoil layer is particularly shallow, no surface disturbance should take place unless specifically advised by an arboricultural consultant. Protruding stones or rocks may be carefully removed by hand or with non-invasive tools, taking care not to disturb surrounding root zones. Where surface roots are exposed, they must be protected prior to the introduction of any sub-base or infill materials. A layer of sharp sand should be carefully applied to form a buffer over the roots. This protective layer serves to distribute weight and reduce the risk of abrasion or compression injury during the placement of subsequent materials.
• Should excavation be required get in touch or consult a professional arboriculturist
• It is advised that all ground preparation work is carried out under the supervision of a professional arboriculturist

• Roll out MultiTrack SNW 40 UV Geotextile to cover the area to be protected.
• Insert 4 equally spaced steel pins along the width of the panel.
• Expand the panel over the MultiTrack SNW 40 UV and the pins, extend to the required length and then pin across the opposite panel end.
• Pin along the length of the panel on each side.
• If full panels are not being used, ensure the cells have been expanded to their full dimension.
• Staple or cable tie any adjacent panels together.
• Install preferred edging detail, for example 'treated timber edging'

Note: ProtectaWeb panels can be cut to shape if required with a heavy-duty Stanley Knife.

Preferred infill should be crushed 20/40 angular stone. If this is not available, 4/20 angular stone can be used. In all situations the infill material should be washed or graded to avoid the presence of fine particles (fines).

• Fill the cells of the ProtectaWeb with a 20/40mm or 4/20mm clean angular stone.
• Allow 25mm overfill for any settlement of the stone into the cells.
• If the area is to be trafficked immediately, slightly increase the amount of surcharge overfill to a maximum of 50mm over the ProtectaWeb with 20/40mm or 4/20mm clean angular stone.
• For temporary installations a typical overfill of 50-75mm of additional material should be suitable
• For final surfacing it is advised that a minimum of 25mm of additional material should be used

The ProtectaWeb TRP system can be surfaced with the materials listed below:

FINISH 1 - PERMEABLE PAVING

• Place MultiTrack 1000 separation fabric over the filled ProtectWeb
• Lay sand/gravel bedding material as per to manufacturer's recommendations
• Place 'permeable blocks'

FINISH 2 - POROUS ASPHALT

• Slightly surcharge the ProtectaWeb with 25mm of 20/40mm or 4/20mm clean angular stone
• Place hot Asphalt as per to manufacturer's instructions

FINISH 3 - RESIN BOUND GRAVEL

• Lay Asphalt carpet and resin-bound gravel to the required thickness and as per the manufacturer's instructions
• Correct build up should be web (including overfill), then porous asphalt base, then resin bound gravel.

FINISH 4 - ECODECK GRAVEL RETENTION SYSTEM - LOOSE GRAVEL

• Place MultiTrack 1000 separation geotextile over the filled ProtectaWeb
• 20mm bedding layer of 5mm single-sized stone and lightly tamp
• Lay Ecodeck porous pavers and fill with a 6-10mm decorative stone

FINISH 5 - ECODECK GRASS PROTECTION SYSTEM

• Place MultiTrack 1000 separation geotextile over the filled ProtectaWeb
• 70mm of Rootzone bedding layer (60% sand/40% soil) and lightly tamp
• Lay Ecodeck porous pavers and fill with Rootzone mix, seed accordingly (please allow 4-6 weeks for the seed to germinate before trafficking)