Piling mat
Pile foundations are a type of deep foundation, principally used to transfer loads from superstructures, through weak, compressible strata or water onto stronger, more compact, less compressible and stiffer soil or rock at depth. They are formed by long, slender, columnar elements typically made from steel or reinforced concrete, or sometimes timber.
They are constructed by displacement (driven) or replacement (bored).
|
|
A piling mat is a type of working platform used for piling rigs to travel on, providing a stable base on which they can move around the site and operate.
The design of piling mats will depend on the ground conditions and the piling equipment being used, as well as the rig loadings (which typically range from 5 to over 150 tonnes). If a piling mat is too deep it will be incurring unnecessary costs, whilst if it is too shallow it may need time- and cost-inefficient repairs. A soft spot in the surface of just 1 sq. m, can be enough to unbalance a rig.
Typically, the top of a piling mat will be around 600 mm above the pile cut-off level, and it will extend beyond the outermost pile positions by at least 2 m. The edges of the mat and the ramps onto and off it should be clearly marked.
The most suitable materials for piling mats are generally well-graded natural gravels, clean-crushed concrete, crushed hard rock, and so on. As long as it has rebar and timber removed, graded recycled demolition material can also be used. Mats are rolled and compacted in layers. The mat should be free-draining to prevent any build-up of water or slurry on its surface. On sites with a high water table, a separating membrane may be positioned between the mat and the sub-grade to prevent the upward migration of fine-grained soils into the mat.
Piling mats should be inspected daily to ensure they are in proper working condition. If any excavations, trenches or holes have formed in the surface, they must be properly backfilled to ensure they are as stable as the rest of the mat.
It is mandatory that every site with an operational piling rig has a Working Platform Certificate (WPC) that states the piling mat has been correctly designed and installed. The WPC must be signed by the principal contractor and provided for the piling contractor before any piling commences on the site.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
UK Infrastructure: A 10 Year Strategy. In brief with reactions
With the National Infrastructure and Service Transformation Authority (NISTA).
Ebenezer Howard: inventor of the garden city. Book review.
The Grenfell Tower fire, eight years on
A time to pause and reflect as Dubai tower block fire reported just before anniversary.
Airtightness Topic Guide BSRIA TG 27/2025
Explaining the basics of airtightness, what it is, why it's important, when it's required and how it's carried out.
Construction contract awards hit lowest point of 2025
Plummeting for second consecutive month, intensifying concerns for housing and infrastructure goals.
Understanding Mental Health in the Built Environment 2025
Examining the state of mental health in construction, shedding light on levels of stress, anxiety and depression.
The benefits of engaging with insulation manufacturers
When considering ground floor constructions.
Lighting Industry endorses Blueprint for Electrification
The Lighting Industry Association fully supports the ECA Blueprint as a timely, urgent call to action.
BSRIA Sentinel Clerk of Works Training Case Study
Strengthening expertise to enhance service delivery with integrated cutting-edge industry knowledge.
Impact report from the Supply Chain Sustainability School
Free sustainability skills, training and support delivered to thousands of UK companies to help cut carbon.
The Building Safety Forum at the Installershow 2025
With speakers confirmed for 24 June as part of Building Safety Week.
The UK’s largest air pollution campaign.
Future Homes Standard, now includes solar, but what else?
Will the new standard, due to in the Autumn, go far enough in terms of performance ?
BSRIA Briefing: Cleaner Air, Better tomorrow
A look back at issues relating to inside and outside air quality, discussed during the BSRIA briefing in 2023.
Restoring Abbotsford's hothouse
Bringing the writer Walter Scott's garden to life.
Reflections on the spending review with CIAT.
Retired firefighter cycles world to raise Grenfell funds
Leaving on 14 June 2025 Stephen will raise money for youth and schools through the Grenfell Foundation.
Key points for construction at a glance with industry reactions.
Comments
Please state where, other than on the PSF website, it is mandated that a WPC to be used as verification of a piling mat. As temporary works, a working platform could be commissioned through a permit to load like any other BS 5975-managed system.