Resin Bound Paving Guide: SUDS-Compliant Aggregate Choice, Primer, Mix Ratios, Depth and UV Stability
Quick Answer: Resin bound paving is a permeable surface formed by mixing 1–6mm dried natural aggregate with a clear UV-stable polyurethane resin (typical mix ratio 80kg aggregate to 6.25–7.5kg resin) and trowelling to 15–18mm depth on a permeable porous asphalt or open-graded concrete base. Done correctly it is SuDS-compliant under the GPDO Class F front-drive rule, lasts 15–20 years, and resists weeds, oil drips and frost damage.
Summary
Resin bound is the rapid-growth product in domestic paving — homeowners like the seamless look, the colour palette, and the absence of weed growth in joints. The product itself is forgiving to install if you stick to the manufacturer's data sheet; the failures are nearly always at the base layer, the resin chemistry, or the weather window.
There are two distinct things called "resin paving" — bound and bonded — and they behave completely differently in regulation, drainage, and longevity. Bonded is impermeable and fails the SuDS test. Bound is permeable and passes. Mixing them up costs jobs.
The market leaders for resin systems are SureSet, Addagrip, Daltex, Resin Mill, and Long Rake Spar (which sells the aggregate). Most product failures in the UK come from one of three causes: cold-weather installation outside the resin's curing window, contaminated or wet aggregate, and applying over a non-permeable base where water builds up at the resin/base interface.
Key Facts
- Permeable — runoff drains through the resin matrix into the porous base, satisfying GPDO Class F for front drives over 5m²
- Standard depth — 15mm pedestrian, 18mm domestic vehicular, 22mm+ for service vehicles
- Aggregate size — 1–3mm for fine finishes, 2–5mm or 3–6mm for standard, 6–10mm for coarse rustic
- Mix ratio (typical) — 7.5–8% resin by weight; e.g. 80kg dried aggregate to 6.5kg resin pack
- Two-pack polyurethane resin — Part A polyol, Part B isocyanate, mixed on site immediately before adding aggregate
- UV-stable resin essential — aliphatic polyurethane only; aromatic resins yellow within 12 months
- Pot life — typically 8–15 minutes once mixed; varies with temperature
- Working temperature — 5°C minimum and rising, 25°C maximum; never on damp or frosted surface
- Aggregate must be kiln-dried — moisture content under 0.2% or resin foams and weakens
- Primer — required on porous concrete bases; not always on porous asphalt; check resin data sheet
- Trowel finish — flat steel float, lubricated with white spirit or release agent, light strokes
- Cure time before foot traffic — 4–6 hours at 20°C, longer in cold conditions
- Cure time before vehicle traffic — 24–48 hours
- UV stability claim — quality systems retain 80%+ colour after 10 years; cheap aromatic systems yellow significantly within 18 months
- Repairability — small areas (1m²) can be patched with the same aggregate-resin mix; the patch is visible because of slight colour difference
Quick Reference Table
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Try squote free →| Aggregate spec | Pedestrian | Domestic drive | Light commercial |
|---|---|---|---|
| Aggregate size | 1–3mm | 2–5mm or 3–6mm | 3–6mm |
| Resin/aggregate ratio | 7.5% | 7.5–8% | 8–8.5% |
| Resin coverage | ~5kg/m² at 15mm | ~6kg/m² at 18mm | ~7.5kg/m² at 22mm |
| Aggregate coverage | ~22kg/m² at 15mm | ~28kg/m² at 18mm | ~34kg/m² at 22mm |
| Base type | Porous concrete or porous asphalt | Porous asphalt 50mm | Porous asphalt 65mm + binder |
| Total system thickness | ~80mm | ~80–100mm | ~120mm+ |
| Indicative cost £/m² (2026) | £75–£100 | £85–£120 | £100–£150 |
Detailed Guidance
Base preparation — where most failures originate
Resin bound is a wear surface, not a structural layer. The base must be permeable, structurally sound, and stable. The two acceptable bases are:
- Porous asphalt (open-graded) — 50mm course over 150mm Type 3 sub-base, laid hot and rolled lightly. The asphalt voids must remain open; over-compaction closes them and the system fails on permeability.
- Open-graded concrete (porous concrete) — typically a 100mm slab with no fines and a clear binder. Less common in domestic but performs well on heavier loads.
Standard non-permeable concrete or sealed tarmac is unacceptable as a base — water reaches the bond line, can't escape, and freeze-thaw delaminates the resin within 2–3 winters.
A new porous asphalt base must be allowed to cure for 7–14 days before resin application. Older bases must be clean (jet wash and dry), free of bitumen bleed (mask if needed), and structurally sound (tap-test for hollow areas).
Primer application
Primers improve resin-to-base adhesion. Most resin manufacturers recommend their own primer for porous concrete; on porous asphalt, primer is often optional or substituted for a thin scratch coat of resin. Apply at the manufacturer's coverage rate (typically 0.2–0.4 L/m²) and allow to become tacky before the first resin pour.
Don't over-apply — primer pooling shows through as gloss patches in the finished surface.
Mixing and laying technique
Forced-action mixers (e.g. Belle Premier 100, IMER Mortarman) are essential — drum mixers don't coat all aggregate evenly. Standard sequence:
- Empty 80kg of aggregate into mixer
- Pour mixed resin (Part A + Part B blended for 30 seconds)
- Mix for 2–3 minutes until aggregate is uniformly coated, no dry pockets, no resin pooling
- Discharge directly into wheelbarrow or onto prepared surface
- Spread to depth using a steel trowel, working back from a fixed edge
The trowel is held flat and lubricated frequently — pulling the aggregate into the previous bay's edge as you go. Keep the same person trowelling the whole job for finish consistency. Joins between batches are invisible if the same operator handles both.
The mix has 8–15 minutes from resin pour to set point. Beyond that, it pulls and tears. Plan batches against the area you can spread in that time — typically 4–6m² per 80kg batch.
Aggregate choice — appearance and durability
Aggregate is the visible element. Quartz, granite, marble and recycled glass are the main UK options. Long Rake Spar publishes a range of natural aggregates from £400/tonne (basic) to £1,200/tonne (designer). For a 100m² drive at 18mm, that's 2.8 tonnes of aggregate — so the aggregate decision drives both look and material cost.
Quartz is the most common choice for durability. Decorative marble looks premium but is softer (Mohs 3) and shows wear in driveways within 5 years. Recycled glass is striking in jewel colours but has sharp edges that wear underfoot — fine for borders, not for full driveway.
UV stability and resin chemistry
Aliphatic polyurethane resins are UV-stable; aromatic resins are not and yellow over time. Aliphatic resin costs roughly twice as much. Cheap "starter kits" sometimes use aromatic resin and the colour shift becomes obvious in 12–18 months. Always confirm the resin chemistry with the supplier and ask for a UV-stability data sheet.
Some systems use "hybrid" formulations — partial aliphatic — which slow but don't prevent yellowing. For a quality residential drive, specify 100% aliphatic.
Failure modes and remedies
- Foaming/bubbling — moisture in aggregate or substrate; replace affected area
- Resin pooling on surface — over-resined batch; rare on factory premixes, common on field-mixed
- Yellowing — aromatic resin used; only repair is full overlay with aliphatic
- Loose stone (de-bonding) — under-resined, contaminated aggregate, or mixed in cold conditions; surface scrub and apply seal coat
- Surface cracking — usually base failure, not resin failure; check for porous asphalt cracking beneath
Maintenance
Resin bound is low-maintenance. Annual jet-wash on a low pressure setting (under 100 bar) clears organic debris from the surface voids and maintains permeability. Resin sealers (clear) can be reapplied every 5–8 years to refresh appearance, though they're not strictly necessary.
Avoid gritting salts in winter — sodium chloride accelerates resin breakdown. Use sand or a non-chloride de-icer.
Frequently Asked Questions
How is resin bound different from resin bonded?
Resin bound is mixed in advance and trowelled at 15–18mm; permeable. Resin bonded is a thin scatter of dry aggregate onto a fresh resin layer (3–6mm total thickness); impermeable, more like a textured paint. Bonded fails GPDO Class F. Bound passes. See resin bonded vs resin bound article for the full comparison.
Can resin bound be laid in winter?
Below 5°C the resin won't cure properly. The realistic UK window is April–October, with extended hours either side if conditions are dry and temperatures rising. Some manufacturers offer "winter resin" formulations that cure to 0°C, but the standard advice is to wait for spring.
How long does it last?
Quality aliphatic systems on a sound permeable base last 15–20 years before needing significant attention. The first failure is usually surface dulling and minor de-bonding at edges, both of which can be addressed with a maintenance overlay rather than full replacement.
Why does my drive look patchy?
Two common causes: (1) inconsistent troweling pressure leading to thicker/thinner zones; (2) batch-to-batch variation in resin/aggregate ratio if measured by volume rather than weight. Both indicate process control issues at install time.
Is resin bound suitable for HGVs?
Not directly — the typical 18mm domestic spec doesn't carry HGV loads. For occasional heavy vehicle access (skips, oil deliveries), specify 22mm depth on a 65mm porous asphalt base over 200mm Type 3 sub-base.
Regulations & Standards
GPDO Schedule 2 Part 1 Class F — SuDS rule on front drives over 5m²
BS EN 13242 — aggregates for unbound and hydraulically bound use in civil engineering and road construction
BS 7533-13:2009 — code of practice for permeable concrete block pavements (relevant for base layer specification)
EN 13501-1 — fire classification (resin bound systems typically class Cfl-s1)
British Association of Landscape Industries (BALI) — installer accreditation scheme
CSCS card — required for installer crews on commercial sites
SureSet technical guides — leading UK manufacturer technical library
Addagrip technical data — second major UK system supplier
Long Rake Spar aggregate guide — natural aggregate sourcing and colour samples
BALI technical reference — landscape installer best practice
resin bonded vs resin bound — the compliance and durability comparison
SuDS regulations for driveways — front-drive 5m² rule
resin bound gravel surfacing — overview of the surface family
tarmac driveway installation — the alternative impermeable surface