As a result, a resin-bound surface is more durable and requires less maintenance – it needs to be swept or power washed at least twice a year, to avoid the build-up of detritus and prevent the growth of moss or algae.
The UV 2 part polyurethane resin should always be sourced from a manufacturer who can demonstrate that they have BS EN UKAS ISO9001 quality management standards (available information on the FeRFA website).
The UV resin sourced should be a two-part, quality-controlled polyurethane or similar with the activator added during the manufacturing process to eradicate mistakes on site made by operatives who are not qualified chemists.
In pavements natural aggregate mix blends tested to BS 8204-6:2008+A1:2010 Appendix B for slip resistance will, when installed correctly, provide a slip-resistant, permeable, decorative finish suitable for pedestrian and light vehicular traffic.
Tree Pit systems are generally installed at a depth of 40 to 50 mm, depending on the specification; they have a reduced ratio of 6% UV light stable polyurethane resin to 100 kg kiln dried aggregate.
Resin bound gravel is particularly sensitive to moisture during the curing process and the presence of water in the mix can cause a reaction in which the polyurethane binder becomes white and bubbles start to form.