MEWP Outrigger Pads: Ground Support for Scissor Lifts and Boom Lifts

IPAF — the International Powered Access Federation — publishes extensive guidance on ground conditions for exactly this reason, and checking the ground before raising a platform is standard content on IPAF operator training rather than something left to a plant manager's risk assessment back in the office. That distinction matters. A crane outrigger settling a few millimetres over a shift is something a slewing operator or a banksman on the ground can catch and correct. A MEWP operator who has already raised the platform gets no such warning — by the time a stabiliser has lost contact, or a scissor lift's chassis has tilted past its limit, the person who needed to know has been up in the air for however long the job has taken.

That is why we see our aluminium mats go out under MEWP outriggers as routinely as they do under cranes and pumps, even though an access platform will never load one anywhere near its rated capacity. On this kind of work the point isn't headroom — it's keeping every contact point flat and level whatever's underneath it, and getting that right before the platform goes up, every time, on whatever ground the machine was driven onto that morning.

Few machines work across as wide a range of ground as a MEWP does. The same scissor lift that spent Monday on a warehouse floor — level, hard, indoors, about as forgiving as ground gets — might spend Tuesday on a worn and patched retail car park, Wednesday on an event site pitched on grass that's had rain on it all week, and Thursday on an industrial yard of compacted hardcore that looks solid but isn't uniformly compacted. A boom lift on a utility or agricultural job might never touch a hard surface at all.

That variety is the real problem. An operator who's spent months on decent hardstanding builds habits — drive out, set up, straight to raising the platform — that are perfectly reasonable on the ground they know and genuinely risky on the ground they don't. "Check the ground" means something different every single time, and the machine itself can't tell hardstanding from a rain-softened field until an outrigger starts to sink into it.

Most boom lifts, and the larger scissor lifts, are built around outriggers or stabilisers making firm, level contact at every point before the platform will rise. Lose contact at one point, or let one corner sink even slightly more than the others, and the stability envelope the manufacturer designed around no longer applies — it assumed four solid points, not three solid ones and a soft one. That's why manufacturer operating manuals and IPAF operator training both treat pads under outriggers and stabilisers as standard equipment for anything short of solid, level hardstanding, rather than something reached for only on obviously bad ground.

There's a second job the pads do that doesn't come up under cranes or pumps in the same way — levelling. Every scissor lift and boom lift has a maximum permissible ground slope or chassis tilt before its own sensor cuts the machine out, a built-in limit rather than a judgement call, so a pad that only spreads load over soft ground is doing half the job. The other half is keeping the machine inside its tilt tolerance in the first place, on ground that might be firm enough to bear the weight but not flat enough to keep the sensor happy.

ALIMATS is our modular aluminium mat system, machined from 6005A alloy and built from five panel sizes — from a 0.58 x 0.58m Mini at 13kg up to a 3480 x 290mm Extra Long at 48kg — that combine into configurations from 1.34m2 right up to 8.07m2. None of that range was designed with MEWPs in mind. The system is rated up to 80 tonnes SWL, every figure independently checked with a Fellow of the Institution of Structural Engineers, because the same mats go out under crawler cranes and concrete pump legs loading several tonnes onto a single pad. A MEWP stabiliser foot will never come close to testing that headroom.

What it does test is flatness and consistency — and that's where the aluminium earns its keep over the plastic mats you'll find on the same sites. Independent bending tests measured ALIMATS deflecting in single millimetres where a comparable UHMWPE plastic mat deflected in tens of centimetres under the same load; the full figures are in our aluminium versus plastic bending test. A mat flexing by more than ten centimetres isn't holding a level surface for a tilt sensor to trust — it's moving underneath the machine while the platform is up.

There's a practical point for access crews too — the panels are handleable, light enough for two people to carry and lay by hand with no heavy plant needed. That counts for a lot on this kind of work, where the operator is often working alone or with a single banksman and there's nothing else on site to shift anything heavier.

MEWP work often lands at short notice — a scissor lift booked for a two-day warehouse job, a boom lift wanted on an event site for the weekend — which is one reason we offer ALIMATS on day, week or long-term hire as well as outright purchase. We run our own FORS Bronze-accredited fleet and deliver 24/7 across the UK, and that counts for more on access work than it does almost anywhere else: ground protection that turns up the day after the machine does is no use to anyone.

Every mat that comes back from hire is inspected, cleaned and checked before it goes out again, so a set of pads that spent last month under a boom lift on a muddy utility site arrives at the next job — MEWP, crane or pump — in a condition we've actually checked, not just assumed.

Stabiliser footprints, ground bearing conditions and machine weights vary so much from one job to the next that there's no single answer to "how many pads" that holds across a warehouse floor and a rain-softened field. The MEWP Outrigger Pad Sizing Calculator below works through your machine's outrigger loads and the ground you're working on to suggest a starting configuration — somewhere to begin the conversation with your ground engineer or plant supplier, on the way to a proper site-specific assessment.