The load-bearing layer

Sub-Base Construction

The sub-base is the layer that carries the loads and keeps the surface stable. We build the right one for your project — MOT Type 3, open-grade tarmac, concrete or permeable grid — correctly compacted and, where needed, free-draining.

What you get

The right base for the job

There’s no single ‘correct’ sub-base — it depends on the loads, the ground and whether the surface needs to drain. We build the one that suits your project, properly compacted.

MOT Type 3

An open-graded, permeable sub-base — ideal beneath permeable resin where SUDS compliance matters.

Open-grade tarmac base

A smooth, stable, permeable binder layer that gives resin an ideal platform to be laid on.

Concrete base

A strong, rigid base for heavy loads or laying over existing concrete — with drainage designed in.

Permeable grid base

Cellular grids that stabilise the ground while letting water drain freely — strong and SUDS-friendly.

Correct compaction

Every build-up is compacted in layers to the right standard — the step most often skimped.

Matched to the loads

We specify depth and material to the traffic the surface will carry, from foot traffic to vehicles.

Upload image: sub-base-construction-1.jpg
alt: Sub-Base Construction — finished project
Upload image: sub-base-construction-2.jpg
alt: resin bound surface detail — close-up

Why choose us

Compaction and the right material are everything

Two sub-bases can look identical and perform completely differently. What matters is the right material for the loads and the ground, laid to the correct depth and compacted in layers. Skimp on depth or rush the compaction — the two corners most often cut — and the surface above will eventually settle, crack or pothole, no matter how good the resin is.

Where the surface needs to stay permeable and SUDS-compliant, the sub-base has to drain too. A fines-heavy or sealed base traps water beneath a permeable surface; an open-graded Type 3, open-grade tarmac or grid base lets it through. We choose accordingly.

Where strength is the priority — heavy vehicles, or laying over existing concrete — a concrete base may be right. Concrete isn’t permeable, so we design in falls and drainage to take the water away rather than leaving it to pool.

Whatever the build-up, it’s specified to the loads, compacted properly, and itemised in your quote.

Why the base matters most

  • The groundwork that makes a surface last — done properly
  • Correct depth, compaction and a stable formation
  • Permeable build-up to keep the surface SUDS-compliant
  • Drainage and edge restraint designed in, not bolted on
  • A fixed quote with the groundwork itemised, not hidden

Sub-base construction matters when…

  • The ground is soft or made-upWeak ground needs the right build-up and compaction to carry a stable surface.
  • Vehicles will use the surfaceVehicle loads demand a properly specified, well-compacted base.
  • The surface must drainA permeable build-up keeps a resin bound surface SUDS-compliant.
  • A previous surface sank or crackedSettlement usually means the original sub-base was too thin or poorly compacted.
  • You're laying over existing concreteAn existing concrete base can work as a sub-base — with drainage designed in.

Work process

How we build your sub-base

Specify, lay and compact in layers — a stable platform built for the loads and the drainage.

01

Assess & specify

We check the ground and loads and specify the right material and depth.

02

Fixed quote

You get a clear, itemised written quote.

03

Prepare the formation

We ensure a firm, level formation to build up from.

04

Lay in layers

We lay the sub-base material to the specified depth.

05

Compact properly

Each layer is compacted to the right standard for a stable base.

06

Check and hand over

We verify levels and falls, ready for surfacing.

Materials

Trusted, industry-recognised systems

We only specify UV-stable resin and graded aggregate from
established suppliers, because the quality of the materials decides how well the surface
drains, holds colour and lasts.

ACOBodpaveGridforceTarmacMarshallsAddagrip

FAQs

Sub-base questions

Which sub-base is best for resin?

It depends. For permeable resin where SUDS matters, an open-graded Type 3, open-grade tarmac or grid base keeps it draining. For heavy loads or over existing concrete, a concrete base may suit — with drainage designed in. We specify to your project.

Is MOT Type 1 suitable under permeable resin?

Type 1 contains fines and doesn’t drain freely, so it isn’t ideal under a permeable surface where you want water to soak through. Type 3 is open-graded and permeable, which is why it’s commonly used for SUDS-compliant builds.

How deep should the sub-base be?

It depends on the ground and the loads — deeper for vehicles and weak ground. We specify the depth to suit, rather than applying a one-size figure.

Why does compaction matter?

An uncompacted or poorly compacted base settles over time, taking the surface with it — cracking and potholes follow. Compacting in layers to the right standard is what prevents that.

Can my existing base be reused?

Sometimes — a sound existing concrete or sub-base can serve as the platform, with drainage addressed. We assess it honestly before recommending reuse or rebuild.

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Explore this section

Sub-Base Construction services

Explore the individual services in this section.

Concrete Base

Where strength is the priority — heavy loads, or laying over sound existing concrete — a concrete base gives a rigid, stable foundation. Concrete…

MOT Type 3 Sub-Base

For a permeable resin surface to drain properly, the base beneath it must drain too. MOT Type 3 is an open-graded, free-draining sub-base that lets…

Open-Grade Tarmac Base

An open-grade tarmac base gives resin a smooth, stable, permeable platform to be laid on. It combines the firmness of a binder layer with…

Permeable Grid Base

Permeable grid bases use cellular grids to stabilise the ground and spread loads while letting water drain straight through. They give strength and…

A sub-base built to carry the surface

Book a free site survey. We’ll specify the right build-up and send a fixed, itemised written quote with no obligation.

Book your free site survey
 0800 107 5166