Car Park Surfacing: Choosing the Right Surface for a Business

For most business car parks, yards and forecourts in the UK, hot-laid tarmac (asphalt) over a properly designed stone base is the default surface: it is quick to lay, takes heavy traffic and can be patched or resurfaced in sections. Concrete earns its place where lorries turn on the spot or fuel and oil are spilled, and resin bound suits pedestrian areas and frontages more than the main traffic lanes. Whatever goes on top, the base, the falls and the drainage decide how long a car park lasts.

Car park surfacing options compared

Tarmac (asphalt): laid hot in at least two layers, a binder course and a surface course, on a compacted sub-base. It is the most common choice because it goes down fast, can be trafficked soon after rolling, and repairs blend in reasonably well. It is not permeable, so the drainage has to be designed around it.

Concrete: rigid, very hard-wearing and resistant to the scuffing that power-steered lorries cause when they turn on the spot. It needs joints to control cracking and takes longer before it can carry traffic, which matters if the site has to stay open. On forecourts and entrances where appearance counts, imprinted concrete for commercial driveways puts a patterned, sealed finish on the same rigid slab.

Resin bound: a decorative, permeable finish that works well on entrances, pedestrian walkways and smaller customer car parks. It is not the surface for a goods yard with daily HGV movements.

Porous asphalt and permeable paving: useful where the site has to manage its own surface water. They need an open-graded sub-base designed to store water, and regular sweeping to stop them silting up.

Our tarmac surfacing is the same process at domestic and commercial scale: dig out to a sound formation, build and compact the base, then lay the binder and surface courses hot. The difference on a commercial job is in the thicknesses and the specification of each layer.

Building the base for vans and lorries

A car park that only sees cars is a very different design from a yard that takes delivery lorries. Pavingexpert's long-standing guidance gives minimums for light-duty bitmac work: a sub-base of at least 100mm, a binder course of at least 40mm (preferably 50mm), and a surface course of 20-25mm once rolled. Those are floors, not targets. Heavier traffic means a deeper sub-base, a thicker binder course with larger aggregate, and sometimes an extra base layer.

What fails in practice is rarely the surface. It is a car park specification put under lorry traffic, a base laid over soft ground without proper compaction, or water left standing on the formation. The signs are rutting in the wheel paths, crazing around gullies, and potholes at the turning points where the load is concentrated. A site visit should look at what uses the site, where the lorries turn and park, and what the ground is like underneath before anyone prices a surface.

Drainage, falls and the planning rules

Surface water is the biggest design job on most car parks. Pavingexpert recommends a minimum fall of 1:80 on tarmac, with 1:40 to 1:60 preferred, and gives a rule of thumb of one gully for every 75 m² or so of paving. Long, flat car parks usually need channel drains as well as gullies, and the water has to go somewhere with capacity to take it.

Planning matters too. The permitted development rules let commercial, business and service premises in England lay new hard surfacing, but only up to a cumulative 50 m² beyond what existed on 6 April 2010. It must also be porous or drain to a permeable area within the site (or be non-porous where there is a risk of groundwater contamination), and the right does not apply within the grounds of a listed building. Industrial and warehouse premises have their own, separate allowance. A new car park or a significant extension will usually need planning permission, and the council may expect sustainable drainage as part of it. Replacing an existing surface like for like is a different matter from creating new hard standing, so check with the planning team early.

Car park layout and lining

Bay layout is easier to get right before the surface goes down than after. The standard UK bay is 2.4m x 4.8m, with 3.6m wide disabled bays allowing a 1.2m transfer zone. The Department for Transport's Traffic Advisory Leaflet 5/95 recommends, for shopping, recreation and leisure car parks of up to 200 spaces, 3 disabled bays or 6% of capacity (whichever is greater), and for business premises of that size, a bay for each disabled employee plus 2 bays or 5% of capacity (whichever is greater). It dates from 1995, so check what your planning authority currently expects.

Lining, directional arrows, hatching and bay numbering go on once the surface has been laid. Plan where pedestrians walk, where deliveries stop, and where snow or leaves will be pushed in winter, then mark it.

Resurfacing a car park while you stay open

Most businesses cannot close the car park for a week, so we phase the work: one section is lifted and relaid at a time while the rest stays in use, with temporary access routes signed around the works, and we keep access running where we can. When you compare contractors, ask each one how they would phase your site, which areas stay open on which days, and how deliveries will get in while the work is under way.

Resurfacing is not always the answer. If the base has failed, a new surface over it will crack along the same lines within a few seasons. Where the base is sound, planing off the worn surface course and laying a new one is far cheaper than full reconstruction.

Car park surfacing questions, answered

How long before a new tarmac car park can be used?

Tarmac can usually take traffic once it has been rolled and has cooled, which is why it suits phased work on a live site. Heavy vehicles turning on it in hot weather can still mark a fresh surface, so lorry routes may need longer.

Is a permeable car park worth it?

On sites where drainage capacity is limited, often yes, as it can reduce or remove the need for new connections. It does need sweeping, and it is not suitable where fuel or chemicals could reach the ground.

Can a steep or sloping site be surfaced?

Yes, but the gradient changes the drainage design and the choice of surface. Our post on steep driveway solutions covers grip and water on slopes, and the same principles apply at commercial scale.

Commercial surfacing in the West Midlands

Drive Tech surfaces car parks, forecourts, access roads and service yards for businesses across Wolverhampton and the wider West Midlands, including drive-thru restaurants and premises where the surface takes constant traffic, alongside our domestic work. For pedestrian areas and frontages, a resin bound finish is worth considering alongside tarmac. If you would like us to look at your site, measure up and talk through phasing, contact us for a free survey and quote.