Knowledge from the University of Resin

Welcome to the University of Resin, we will provide you with a wealth of  knowledge in the materials used, methods and tricks of the trade gained from our 25 years experience in commercial Civil Engineering, surfacing, drainage and 11 years of that experience using resin bound surfacing across a vast array of projects throughout the UK.

What bases can resin bound be used on?

Existing Surfaces that can be over laid: Tarmac (surface must not have no movement or loose areas), Block paving ( surface must have no loose bricks, sink age or spreading of blocks), Patio’s ( surface must have no moving/rocking slabs), Concrete ( must have no major cracking/ smashed areas). All surfaces must be clean and free of any debris.

Typical Base construction for a 25 year 100% permeable resin driveway (SUDS compliant)

Excavate the area to 270mm, insert approximately 150mm of type 1 stone (MOT) rolled and compacted, 100mm C10 permeable concrete, and 18mm resin stone, 2mm tolerance. To keep compliant with SUDS when the concrete is laid, it must  allow for drainage, the new sub base itself is 100% porous with microscopic voids between each stone allowing water to pass through like a sieve, nothing is stronger or has the life span of concrete especially for 25 years.

Product Detail

The Stone

The stones are excavated from gravel pits predominantly in the UK, but also from around the world. It arrives in 20-75mm pieces and is then screened to 1-3mm, 2-5mm, 3-6mm, washed, kiln dried and then bagged after drying. These bags are then stored in a temperature-controlled environment to prevent condensation; if any bags develop condensate, then they will be unusable due to the water-based polyurethane resin as this will create weakness within the structural integrity of the material and discolouration. The stones are all-natural colours, not manmade hence why they do not discolour.

The Resin

The resin is UV polyurethane which is water-based, giving it the extra strength and flexibility that other types of resin do not possess. This type of resin is mainly used on the hull of ships due to the strength and flexibility but is chemically adjusted to bind with the stone as well as any other type of material to be bonded. The correct resin should be brought for the appropriate application.

As the resin is clear we can use different coloured stone unlike other products, i.e. concrete is mixed with stone grit and cement, and due to the cement (binder) being grey, the overall finish is grey. Tarmac is stone and bitumen, as the bitumen is black, the finish is black. There are two types of resin-bound binder; one is standard of which over a 2-week period discolours to a yellow and even green colour on certain whites and silvers.

The Mix

There is an optimum mix of resin and stone necessary to achieve a 25-year surface (if installed correctly). The mix consists of 50kg of 2-5mm stone, 50kg of 1-3mm stone, 5kg of fine sand and 7.5kg of resin; this will then create a solid, dense surface. This is laid at a 20mm thickness and once trowelled is compressed to 18mm. At 15mm our resin mix will take 30 tonnes before breaking, so the base must be good, as Civil engineers we recommend 100mm of permeable concrete for structural integrity on the domestic driveway, this is the only base to be used to achieve a 25 year resin surface. Tarmac is not a 25 year product and needs replacing every 5 years to retain its 25 year structural base integrity, as we all know the forever replacing of tarmac along our roads and foot paths.

The resin mixture is not to be laid in the rain as can cause discolouration and weakness within the new surface .

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    Construction of a Typical Driveway

    Excavate the area to 270mm, insert approximately 150mm of type 1 stone (MOT) rolled and compacted, 100mm C10 permeable concrete, and 18mm resin stone. To keep compliant with SUDS when the concrete is laid if you have not used the permeable concrete you must puncture to allow for drainage. The resin and sub base itself is 100% porous – once trowelled the stones are knitted together with resin-level microscopic voids between each stone allowing water to pass through like a sieve.


    Sustainable Urban Drainage Systems which came into place by local authorities in January 2015, but the changes were set out in December 2014. SUDS Non-Statutory technical standards for the design, maintenance, and operation of sustainable drainage systems to drain surface water on your own land.

    This prevents the local storm and sewage water drainage system being flooded. When the system is overloaded, the sewage company must open the gates on the river and let out untreated sewage into the local rivers killing fish and local wildlife habitation. So, in effect, by having a SUDS compatible surface, you’re having a positive impact on the environment.

    General problems 

    1. Dark Patches, Once resin surface is finished sometimes you get dark patches looking blackish in places across the surface!
      1. This is simply micro metal fillings from the trowel used to level and close the stone, the micro metal fillings forms in a grey residue on the bottom of the trowel and is only within the film of resin on the top and will wear off in time leaving a natural stone finish, common in lighter colours.
      2. The stone has been left to long in the mixer again the micro metal fillings (grey residue) off the side of the drum created by the scrapping of the stone against sides of the drum is then mixed into the mixture contaminating the colour.
      3. One of the bags used in the mixture was wet creating a darker patch and will take a very long time to disappear if ever.
    2. White Grey marks, If you find next day after installation of the resin you have white frosty grey looking patches or bands of it through surface, the resin surface has suffered water or rain damage. Can sometimes be re sealed to restore colour, otherwise its a overlay.
    3. Loose stones or cracking, loose stones is an incorrect mixture of the resin and or  stone. the smaller the stones the more stronger the surface also more KG of resin the stronger the bind. Due to this begin a national problem, BBA which is a minimum standards agency certification and the minimum requirement for a resin bound mixture is 75% 2-5mm stone and 25% 1-3mm stone 6.25kg of 50/50 sands and 7.5kg of resin. As a supplier to the construction industry we supply above the minimum standard for value for money. our mix is a 50% 1-3mm stone x 50% of 2-5mm stone with 7.5kg of resin and 6.25kg of fine sand. Cracking if surface is to minimum BBA specifications and not had more than 3.5-tons in weight upon the driveway then it is down to the sub-base installed has occurred movement. Our driveway spec’s hold 13 tons as standard.
    4. Slippy driveways this has been caused by no anti slip non- skid materials used within the resin mixture, some companies use a glass dusting method to throw across resin surface once trowelled, but unfortunately this does not provide for long if at all a non slip surface as the dusting of the crushed glass is only micro millimetres thick on the surface simply stuck to it by a slight residue of surface resin, this will ware of in no time and has a problem of collect dirt therefore seeing tyre marks in and out of a driveway, the resin has coated the stone protecting them from dirt and stains and will just wash away but the glass film is not protected the glass can stain and also cause white patches.  Anti slip properties is in the finer stones and 50/50 sand of which is mixed within the mixture of resin and stones and begin protected and held into place with the resin, the sand also gives the product strength as the tighter and dense you can keep a surface the longer the durability will be.
    5.  Uneven look at dusk or under light, Sometime at night or when you drive in at night you notice that wasn’t there in the day light that the surface looks very uneven, trowel marks ridges within the surface looking pretty horrendous. This is simply the quality of the hand trowelling, this cannot be helped entirely as it is a hand trowelled product, but should not feel under bare foot or rubbing you hand across surface uneven or lumpy and would not be able to see within the daylight hours when sun is high. Power trowelling method completely minimises dark patches cracking loose stones and a level finish on the resin without trowel marks. You will never get a out door driveway completely flat as the driveway has to go with the lay of the land within reason.