Resin-bound or resin-washed stone: which surface for driveways and paths?

Resin-bound and resin-washed paving look like cousins from a distance and are often quoted under the same heading — “resin paving”. They are not interchangeable. One is a load-bearing wearing course; the other is a decorative finish that happens to be mineral. Choosing the wrong one is expensive, not because the material is poor, but because the wrong material is being asked to do a job it was never formulated for.

The short version

Resin-bound mixes graded aggregate through a polyurethane binder, spreads and compacts it, and cures into a continuous, load-spreading mat. The stone is held on all sides, the surface reads as solid paving, and water passes through the voids between grains rather than across the top.

Resin-washed broadcasts aggregate onto a resin bed and then washes the surface resin back, so the stone stands proud of the binder. The result reads like loose gravel that has agreed to stay in place: open, tactile, free-draining, and visually softer than a bound surface.

How they behave under traffic, water and frost

Property	Resin-bound	Resin-washed
Typical use	Driveways, access roads, plazas, pool surrounds	Paths, borders, courtyards, tree pits
Traffic class	Foot traffic up to light vehicles; heavier duty by build-up	Foot traffic and occasional light loads
Surface	Closed, walkable, visible stone through the binder	Open texture, pronounced “gravel” feel underfoot
Water	Permeable when laid on a permeable base; voids can silt over time	Free-draining by design
Repair	Local patches blend reasonably well	Patches are visible unless re-washed
Where it wins	Anything that has to carry a car and still look like stone	Anything that has to look like gravel and stay put

Ranges vary by system. The gradation and binder ratio on the technical data sheet for the grade you are specifying govern coverage, cure and load class — treat any figure here as a starting point for that conversation, not as a specification.

What actually decides the specification

On a real project the aggregate is rarely the hard part. Five things decide whether the surface is still there in five years:

1. The base. Concrete or asphalt needs to be sound and drained; a loose aggregate base needs the right layer thickness, compaction and a geotextile separation layer. A perfect mix over a moving base fails on schedule.
2. Aggregate size and colour. Fine grades read as smooth paving, coarser grades as gravel. Colour is usually matched to a RAL or a client sample, and the recipe should be locked in writing before the container ships.
3. Binder ratio and mixing. Two-component polyurethane, mixed in a forced-action mixer at the ratio on the TDS, within the stated temperature window. Eyeballed ratios are the single most common cause of a surface that never hardens properly.
4. Falls and drainage. Permeable does not mean “water disappears”. The base has to take the water away.
5. Edge restraint. Most failures start at the edge — a thin, unrestrained margin crumbles first, then water gets underneath.

Climate questions worth asking before you buy

• Freeze–thaw: water in the voids expands. Ask what the system does through repeated cycles on your base, not on a laboratory slab.
• High UV: colour stability lives in the binder and the pigment choice. Say which market the surface is going to.
• Coastal salt and humidity: affects cure and, over time, the appearance of the binder film.
• Heavy rain: a permeable build-up needs somewhere for the water to go.
• Heat: very hot surfaces soften some binders; the grade should be chosen for the summer temperature where it is laid, not where it is made.

Five mistakes that ruin a resin surface

1. Wet or damp aggregate — the binder cannot wet the stone and the surface dusts.
2. Wrong binder ratio, or mixing more than can be laid within the pot life.
3. No primer, or the wrong primer, on a concrete substrate.
4. Laying over failing asphalt without removing or stabilising it.
5. No edge restraint, or an edge too thin to take the load.

What we need from you for a quotation

Send the area in square metres, the substrate, the aggregate size and colour you have in mind, the traffic it has to carry, the destination port and your target date. If the finish matters more than the grade, send a photograph or a competitor sample — a physical sample board is the only reliable way to agree a colour across a container.

We quote in writing with the grade, coverage, packaging (bags or bulk), MOQ and lead time, and we ship FOB or CIF from Qingdao and Tianjin. If a document you need does not exist for a given grade, we say so rather than inventing a number.

Questions we get asked

Can resin-bound stone be laid over existing concrete?

Yes, provided the slab is sound, dry, free of loose material and has falls for water. A primer or bonding coat is normally specified, and the surface is built up in one continuous pour.

How soon can it take traffic?

Foot traffic is usually possible the same day and vehicles after the cure window stated on the technical data sheet for that grade — the binder chemistry, not the aggregate, sets the clock.

Is a resin surface slippery when wet?

The texture does most of the work: the exposed aggregate gives grip, and a correctly built permeable base stops water sheeting across the surface. Where a client requires a declared slip value, that is a test result to request with the TDS, not an assumption.