Ekki
Also called Azobé, Lophira alata, Timber crane mat, Hardwood mat
A dense, naturally durable tropical hardwood (Lophira alata), widely used for crane mats and timber baulks because of its high strength and resistance to decay and abrasion. Ekki mats are heavier than aluminium or plastic mats of similar size, and their load capacity can vary with moisture content and natural defects such as knots and splits.
In practice
Timber is the trade’s default and it works, but it is a natural material, and that is the whole difference. Two ekki mats of the same size can differ in what they will carry because the grain, the knots, the splits and the moisture content differ — a manufactured mat is made to a specification and a timber mat is selected against one. Ekki also gains weight as it takes up water, so the mat that goes out is not always the weight of the mat that comes back.
Where this comes from: Long-standing UK ground protection practice. Capacity figures for a timber mat come from the supplier of that mat and its grading; nothing here is a rating for any particular timber product.
Where it matters on site
The comparison worth making is by whole-life cost and handling rather than by purchase price, where timber usually wins on the day. Against that sit handling weight, water uptake, splitting and end-checking in service, degradation under repeated use, and the difficulty of inspecting a used timber mat and saying with confidence what it will still carry. Which matters most depends on how often the mats move and who has to move them.