Ground Protection Mats for Construction: Specify Thickness by the Heaviest Machine on Site

Specify construction ground protection mats from the heaviest machine, not the fleet average: 15 mm for rubber-tyred trucks on firm ground, 20 mm for tracked excavators, loaded dumpers and soft subgrade, and 12.7 mm only for finished surfaces. Add a 15–20% margin. These panels spread distributed wheel loads — not crane outrigger pads, temporary bridges or permanent roads.

This page covers the working surface: site entrances, track-out aprons, compounds, work platforms and finished-surface protection. A continuously trafficked haul road — lane widths, swept paths, staggered joints and a 300 m take-off — is a different load case; see temporary access roads. The entrance and the road are often on the same order but are sized differently: the entrance sees braking, turning and the highway transition, the road repeated rolling passes.

What construction ground protection mats are

A construction ground protection mat is a removable load-spreading panel laid over soil, turf, a finished slab or a working platform so machines can pass without rutting the ground or marking the surface. Each 1,220 × 2,440 mm (4 × 8 ft) HDPE panel covers 2.98 m² (32 sq ft), carries dual-face tread — a vehicle face and a pedestrian face — and is moulded with 4 hand holes and 8 connector holes. Connected edge to edge, the field spreads a wheel load over a larger footprint than the tyre patch and shares braking and turning forces across the joints.

Ground protection mats for construction describes the product; a construction site access surface describes the arrangement — entrance geometry, track-out control, subgrade, connections and reinstatement. Tenders that list only a panel count usually omit the highway transition, the turning allowance and ground preparation, which is where cost overruns start. Standard sizes are on our 4 × 8 ft ground protection mats and specifications pages.

Typical plant includes 6–12 t site dumpers, telehandlers, 20 t rubber-tracked excavators, 30–40 t rigid tippers and light vans. Rubber tyres and rubber tracks are in scope; sharp steel grousers are not. The design case is always the heaviest single machine at the worst ground condition, not the fleet average — a 20 t excavator that visits once still governs if it crosses the entrance. The three thicknesses are not interchangeable: 12.7 mm is a finished-surface sheet, 15 mm the default for rubber-tyred trucks on firm ground, 20 mm the start for tracked plant, laden dumpers and marginal subgrade.

When to use them — and when not to

Do not use our type of HDPE panel when:

• A crane outrigger, critical lift pad or piling rig support — a concentrated point load needs a separate engineering case.
• Sustained steel-track traffic — sharp grousers cut and abrade HDPE; evaluate composite, timber or steel instead.
• Bridging a void, trench, culvert, service or uncompacted backfill — these panels are load spreaders, not beams or temporary bridges.
• Deep, unbounded soft silt or peat with no bearing layer — the field will migrate; ground improvement or timber bog mats come first.
• A permanent road, public traffic or a certified highway/accessibility specification without a separate assessment and edge ramps.
• Saturated ground that cannot be drained — derate, drain and separate first; a thicker board over wet clay still sinks at the edges.

Stating these limits costs an order occasionally, but it prevents the failure that costs a programme a week of downtime — and it is the first thing an experienced site engineer checks. Where a lift plan or permit applies, obtain a site-specific engineering assessment; we would rather tell you to buy a rated pad than sell a board that does not meet the calculation.

How to install and use them on a construction entrance

A construction surface fails at its edges and joints far more often than in the middle of a panel. Use this seven-step sequence for an entrance apron, compound or protected surface; a fuller procedure is in how to install ground protection mats.

1. Walk the area and mark ground zones — soft spots, standing water, services, the highway boundary, the firm-ground transition.
2. Drain before you lay. Cut an intercept drain or pump standing water; a panel over saturated soil pumps fines into the joints from the first pass.
3. Roll out geotextile with generous overlap on fine-grained or wet soil; select the grade for the soil and anchor against wind.
4. Start on firm ground and work outward, so the first panels always have support; never span a hollow.
5. Stagger by half a panel, orient the tread, connect every panel. Vehicle tread up on lanes, pedestrian tread up on finished surfaces. Use listed half-width panels at row ends rather than cutting, and the right connector type for the turning loads.
6. Run one laden vehicle at walking pace, then re-inspect for edge settlement, joint opening and migration at the highway transition.
7. Recover, wash and store flat, lifting from firm ground backwards; inspect hand holes and connectors and stack supported to avoid creep.

Worked example: a 40 m site-entrance track-out channel

Illustrative quantity take-off, not a design value — substitute your geometry and confirm the heaviest machine before ordering.

Two details matter more than the arithmetic. Stagger joints by half a panel — a continuous seam under a wheel path opens under braking; our listed 610 × 2,440 mm panels close alternating rows without field cutting. Extend the channel onto firm ground so mud does not reach the highway, with a rumble or scrape zone at the boundary. Published industry guidance puts a 40 ft high-cube container at roughly 300–350 panels at 20 mm (industry reference range, to be confirmed), so this entrance is well inside one container.

What it saves: an auditable cost comparison

The honest comparison is mats versus a crushed-stone entrance over the project life. For the 40 m × 4.88 m entrance above, a 300 mm aggregate layer requires roughly 58.6 m³ of stone (40 × 4.88 × 0.30), about 94 t at a typical 1.6 t/m³, or 4–5 lorry loads — before grading, track-out cleaning and, most often forgotten, excavating and disposing of the stone at hand-back. A panel field needs no aggregate and leaves the subgrade intact.

Use your own rates, not a headline price:

Cost per use = (delivered cost + handling + deployment labour + cleaning + storage
 + losses + reinstatement) ÷ number of deployments

The break-even point depends on how many times the same panels are redeployed. Our cost and ROI guide sets out the calculation; for a single short project, hiring may beat buying. We will not quote an invented case — use your own downtime, hire and reinstatement rates.

Why this mat — not a lighter panel or another material

Why not the cheaper, thinner board? On a live site the cost is not the panel, it is the interruption; a working joint under a braking 40 t truck costs far more than the 12.7-to-20 mm difference. Why not the thickest board? Beyond 20 mm, weight, handling and container utilisation deteriorate, and extra stiffness still will not fix an unprepared subgrade — spend the first unit of budget on drainage and geotextile.

Linked panels also resist the horizontal forces that push boards apart on a bend, and batch-to-batch compatibility matters because a mixed-thickness field does not sit flat. For a heavier-duty working platform, see our heavy-duty panels — still subject to the calculation below.

Original selection matrix: equipment, thickness, handling and entrance track-out layout

This construction-entrance matrix appears on no other scenario page. The handling column is a method, not a weight: confirm it with a sample panel at the entrance.

Why 15 mm is the default and 20 mm the upgrade — the derivation chain

Work the selection chain in order. The figures below are an illustrative engineering check, not a certified design value.

Three qualifications apply:

1. We have not used our published nominal ratings in this calculation. Our published reference ratings — 80 / 100 / 120 t for 12.7 / 15 / 20 mm — are nominal figures for evenly distributed static loading on a firm, level subgrade. They are not certified design values and must not be used as point-load capacity, crane outrigger capacity, or a permit-to-bridge voids. We publish no test method, sample thickness, support span or test report for these figures; they are labels, not design inputs.
2. Confirm the thickness convention. Ask whether a quoted figure is the base sheet or overall height including raised tread; the difference can approach 10 mm (industry reference) and changes stiffness, stacking height and edge ramps. See how to choose ground mat thickness.
3. Thickness changes freight. At 20 mm the same container carries fewer panels than at 15 mm (industry reference range, to be confirmed), so delivered cost per square metre rises twice — once for resin, once for shipping.

This is a selection starting point, not a certified design value. Confirm against the heaviest machine on site, not the fleet average. Where a lift plan or permit applies, obtain a site-specific engineering assessment. Common mis-specifications: choosing by average weight, treating a nominal tonnage as permission to bridge a hollow, buying thickness instead of drainage, and putting 12.7 mm under a laden dumper.

Common failure modes and how to avoid them

What to verify with any supplier before you buy

Before a quantity becomes a purchase order, ask every bidder — including us — for the same seven things. This tells you what to request, not what we already supply.

1. Is the load figure static, dynamic, distributed or point, with sample thickness and support span? A number without a test condition cannot enter a calculation.
2. Base sheet or overall including tread?
3. What crew or plant places panels at the chosen thickness, and can the entrance be relaid after the first pass? Decide from a sample-panel trial at the site entrance.
4. Thickness tolerance and batch consistency record? A linked field needs panels that sit flat.
5. Material declaration — virgin HDPE, regrind or PCR, UV stabilisation?
6. Connectors supplied, compatible across future orders?
7. A test report with an identifiable method and laboratory plus a loading plan? Treat a figure without a documented method as a marketing claim, not a design input; the contact page is for ordering, not for replacing a test report.

A construction order often runs to several containers, so a single approved sample says little about the batches that follow. When we quote we can include dated working photographs of the line running, a thickness check on a finished panel and that order being loaded — useful for seeing how the panels are packed, but not for establishing a tolerance. Ask separately for the numeric tolerance, batch inspection record and loading plan; none of those can be read from an image.

Specification summary for a construction site entrance

Frequently asked questions

How many ground protection mats do I need for a site entrance? For a 40 m × 4.88 m two-panel-wide entrance, 40 ÷ 1.22 gives 33 rows × 2 = 66; add 15–20% for track-out, transition and turning — roughly 78 panels. Substitute your geometry and confirm the heaviest machine and worst subgrade before ordering.

What thickness mat for a 20 ton excavator? A 20 t rubber-tracked excavator is where we start at 20 mm, not 15 mm: tracked, concentrated at the entrance, rarely level ground. Add 15–20% and confirm against the heaviest machine. If steel-tracked, HDPE is the wrong material — evaluate composite, timber or steel.

Can trucks drive on HDPE mats in mud? On firm, drained ground, yes. On saturated clay or peat, only after derating, drainage and a geotextile layer; industry guidance puts saturated-soil bearing loss at 30–50% versus dry compacted soil, and a thicker board over an unprepared subgrade still sinks at the edges. Drain and separate first.

Should I size the mats for my heaviest machine or the average truck on site? The heaviest machine. A fleet average hides the laden dumper or tracked excavator crossing at the worst moment and worst ground condition. Specify against that case, add 15–20%, and verify the result with a site trial and the supplier’s test conditions.

When is 12.7 mm acceptable on a construction site? Only as finished-surface protection — a cured slab, block paving or turf that must not be marked by light traffic — with the pedestrian tread face up. It is not a haul surface for laden trucks or tracked plant.

Are these panels a substitute for crane outrigger pads or a temporary bridge? No. The published 80 / 100 / 120 t figures are nominal distributed static ratings on firm level ground — not certified design values, not point-load capacities and not permission to bridge voids. Each needs its own calculation and, where a lift plan applies, a site-specific engineering assessment.