Resin Bound Surfacing
Introduction
Resin Bound surfacing (Trowel applied) is a type of exterior surfacing commonly used on domestic driveways, pathways or commercial projects due to its highly decorative appearance, strength and permeability. Decorative aggregates are mixed with a resin and then trowel applied to a base as a screed at a depth defined by the sub-base and desired end use of the finished surface. When cured this creates a smooth, glossy surface in which the stones are bound together by the clear resin.
Image owned by Star Uretech
Despite the claims of some suppliers, Bound surfacing resin is NOT a DIY product and installing a resin bound surface requires both specialist training and equipment. At Star Uretech we do not sell our products online and we carefully check our customers credentials before supplying our products. This ensures that if our products are used, the installation will be of the very highest quality. The image on the left is a safety data sheet from an industry standard element of a resin bound kit.
System Types
There are five system types which fall into one of three categories. UV Resistant, UV Stable and Non-UV Stable. Star Uretech will only ever sell a 100% UV resistant system.
UV Resistant: Naturally resists UV rays and prevents UV degradation.
UV Stable: A stabiliser is added to a non-resistant resin to protect it from degradation however as the stabilisers absorb UV radiation they ultimately fail.
Non-UV Stable: Sometimes referred to as 'buff' resin, non-UV stable systems suffer from polymer degradation which results in gradual changes to the colour and tensile strength of the system.
The most common system types in the UK are Aliphatic Hybrids (UV Stable) and Aromatic (Non-UV stable) products however, as industry knowledge and standards improve, UV resistant systems (Such as StarScape ULTRA) are becoming more common. There are actually five types of resin bound (trowel applied) systems available:
● Aliphatic (100% UV Resistant) (StarScape ULTRA)
Commonly referred to as ‘UV Resistant’ or ‘UVR’, 100% Aliphatic systems are the best choice for a decorative resin bound surface. When cured, aliphatic systems do not discolour or degrade and produce a strong but slightly flexible surface. More and more installers are either switching to or introducing an aliphatic system and we advise anyone thinking of having a resin bound surface installed to confirm that the selected resin is an aliphatic formulation.
● Aromatic (Not UV Stable)
Often called ‘Non-UV’ or 'Buff resin' these are the cheapest types of system as they are not UV stable, discolour in sunlight and ultimately degrade. The discolouration can leave a non-uniform, patchy, dark and dirty looking surface which can also be vulnerable to reflective cracking. It is our view that anyone having a decorative resin surface installed should avoid aromatic products in order to ensure the installation maintains its long lasting, decorative appearance.
● Aliphatic Hybrid (UV Stable / Not resistant)
These systems are often called 'UV Stable' or ‘UVS’ and they are either a blend of aromatic & aliphatic isocyanates that have UV stabilisers incorporated into the resin or they are a poorly formulated aliphatic system which requires UV stabilisation to counteract catalyst residue or other impurities. Stabilising a system delays the discolouration and surface degradation but does not prevent it.
● Epoxy
As a resin used for exterior surfacing this old technology has all but disappeared and has historically been very problematic. Its performance, hazard rating, costs and installation difficulties have all been contributory to decorative epoxy systems being phased out of use.
● Aspartic
This is a relatively new type of system in the decorative resin market and Star Uretech has patented a decorative surfacing product based upon this chemistry. Whilst such a system does offer many benefits, we believe that the aspartic catalyst technology is not yet adequate and the additional costs associated with aspartic formulations currently prevent them from being competitive.