Addastone Tree Pit System

A UV stable polyurethane resin designed to bind natural and recycled aggregates to provide a fully bonded and attractive porous surface to tree pits or walkways.


Areas to be filled with resin bonded aggregate must be clean and dry with a minimum infill depth of 50-100 mm, 25mm depth if areas are not to be walked on. A quantity of loose chosen aggregate to be mixed with the PU Addastone TP UV RESIN should be applied to the area at a depth of 25-50 mm below the top surface level depending on expected pedestrian traffic loading.

Aggregates used must be washed, clean and dry with a minimum grading of 2–5 mm, for greater percolation of water a minimum grading of 6-10 mm should be used. A suitable protective collar should be installed 50–100 mm from the base of the trunk to allow for growth.

General information

Uniclass 2015

Pr_35_31_05_70 Resin-bonded aggregate surfacingsPrimary


Q10/305 Tree grilles and surrounds

Q22/175 Proprietary pedestrian paving

Q22/185 Proprietary surface treatment to existing paving

Q22/365 Proprietary surface treatment

Specification data - Resin-bonded aggregate surfacings

Product Reference

Addagrip PU Addastone TP UV Resin Bonded Surfacing for tree pits


25 mm to 75mm depending as required

Aggregate size/ colour

6-10 mm Rhine Gold

6-10 mm Brittany Bronze

6-10 mm Trent Pea Gravel

6-10 mm Red Granite

6-10 mm Silver Grey Granite

6-10 mm Dorset Gold

6-10 mm Corn Flint

Standard product features


Light Pale Yellow (translucent).

Mixing/ application:

The contents of PU Addastone TP UV Resin Part ‘B’ should be added to container PU Addastone TP UV Resin Part ‘A’ and thoroughly mixed together using a forced action drill and paddle or similar. Immediately add catalyst Part ‘C’ and thoroughly mix again using the drill and paddle. The mixed PU Addastone TP UV Resin should then be poured on to the chosen aggregates placed in a forced action mixer and mixed thoroughly until all aggregate is coated in resin. Approximate ratio of aggregate to resin is 1 kg PU Addastone TP UV Resin to 20 - 25 kgs of aggregate, for a stronger bond this should be reduced to 20 kgs.

The mixed resin and aggregate should then be placed in the area to be filled and trowelled to a flat finish. While the resin is still wet apply a scattering of kiln dried quartz or similar to improve skid resistance.

Do not apply in wet conditions. Recommended temperature of application should be +5°C up to +30°C. Allow to cure for 3-6 hours at 18°C.

It is recommended not to apply the resin bonded aggregate to the area between the tree trunk and the protective collar; fill gap with loose aggregate to allow the tree space to grow. If the resin bonded finish is to be applied up to the tree trunk apply thinly and feather off as required to the depth of the aggregate used 6-10 mm.

Product Options

Nominal thickness:

Resin bonded aggregate thickness: 25–75 mm.


A range of aggregates and recycled aggregates is available from various aggregate suppliers. Contact Addagrip for details and advice on the suitability of the chosen aggregate, particularly in relation to the porosity.

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