King post retaining walls
King post retaining walls
King post retaining walls are a versatile, strong, and efficient solution for ground retention in UK construction projects. When properly designed, installed, and managed, they offer a reliable alternative to traditional retaining wall systems—especially where access, time, or excavation is limited.
What is a king post retaining wall?
A king post retaining wall is a type of retaining structure that uses vertical steel posts (king posts) embedded into the ground, with timber, concrete, or precast panels placed horizontally between the posts to retain soil.
They are commonly used in the UK construction industry for:
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Temporary and permanent ground retention
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Sloped ground stabilisation
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Residential and commercial developments
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Areas with restricted access
King post retaining walls are valued for their strength, flexibility, and speed of installation.
What is the lifespan of the steel king posts?
The steel post sections can be hot-dipped galvanised to prevent corrosion. Galvanising offers a modern-style wall boasting a lifespan of 40-60 years.
When the post is being encased in concrete, no protection is required. The posts can be painted above ground to prevent corrosion. We recommend a resin-based paint system to extend the lifespan of a steel king post.
What are King post panels?
The concrete infill panels are also structural as they must take the load and resist bending. The concrete infill panels are reinforced with steel to give them maximum structural stability.
It’s essential to have the king post retaining wall designed to ensure it works for the long term, which is why we supply textured, and plain concrete panels.
What are king post panels made of?
The panel for a king post retaining wall can be made from:
- Timber sleepers
- Plain concrete
- Textured concrete
What are the dimensions of a king post panel?
- For textured concrete panels, the panels are 1750mm long for 1.8m post centres.
- For plain concrete, the panels are 2450mm for 2.5m post centres.
We highly recommend getting a structural engineer to design the wall first. This is a service we can provide, click here for an initial quote.
Click on the links below to visit the product pages of our textured and plain concrete king post panels.
TexturedKing post retaining wall design guide
What are the dimensions of a king post retaining wall?
| Height (mm) | 500 | 1000 | 1500 | 2000 | 2500 | 3000 | 3500 |
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| Post Centres (mm) | 2000 | 2000 | 2000 | 2000 | 2000 | 2000 | 2000 |
| Post Section | 152 x 152 UC | 152 x 152 UC | 152 x 152 UC | 203 x 203 UC | 203 x 203 UC | 203 x 203 UC | 254 x 254 UC |
| Post Weight (kg) | 23kg | 23kg | 30kg | 46kg | 60kg | 86kg | 107kg |
| Post Embedment (m) | 0.5 | 1.0 | 1.5 | 2.5 | 3.5 | 4.5 | 5.5 |
| Post Length (m) | 1.0 | 2.0 | 3.0 | 4.5 | 6.0 | 7.5 | 9.0 |
| Post Hole Diameter (mm) | 450 | 450 | 450 | 450 | 450 | 450 | 450 |
| Surcharge | 10kn/m2 | 10kn/m2 | 10kn/m2 | 10kn/m2 | 10kn/m2 | 10kn/m2 | 10kn/m2 |
| Factor of Safety | M=1.5 | M=1.5 | M=1.5 | M=1.5 | M=1.5 | M=1.5 | M=1.5 |
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The design table above shows indicative designs for king post retaining walls based upon an average soil type, and is a guide only.
The design uses well-graded, granular backfill with the back of the wall having drainage to relieve hydrostatic pressure.
All indicative information presented in this table is based upon assumed loading and ground conditions. The table is for guidance purposes only and may be subject to change following a detailed, site-specific design developed by an approved structural engineer.
All retaining walls need to be designed for local soil conditions and caseloads. Go to our design section to learn more.
King post installation services
Get expert assistance for the flawless installation of your king post project. Enhance the stability and durability with our skilled team.
Gallery of King post retaining walls
Compare prices of retaining wall types
Which retaining wall type is the most economical to build? We have written a free guide on retaining wall price comparisons. The guide details the different types of retaining walls and gives you a price estimate of each type to compare.
Retaining wall price comparison guideKing post retaining wall design service
The design of a retaining wall requires knowledge of the retaining material, the water table, the ground bearing capacity and any site constraints. The design requires a ground investigation and a structural engineer to ensure the design is fit for purpose.
We offer a full design service from carrying out the ground investigation to final working drawings.
Learn about our retaining wall design serviceOther types of walls
FAQs about King post retaining walls
The depth of a king post is normally about 1.25 times the height of the wall. If the wall is 1m the post hole will be 1.25m The actual depth depends on the load case and ground conditions.
The cost to build a king post retaining wall changes with the height of the wall, scale of project, location of the project and any site constraints.
We do have a comprehensive price table and budget calculator in our price guide. The price guide costs change over time so we keep it in one document.
You can download the document from this link. Get the price guide.
The panels can be made from timber, steel, or concrete. The most common is concrete as it lasts longer than timber. If the look of the panels do not matter pre-cast lintels can be used.
Concrete panels can be plain smooth concrete or they can be patterned. Timber and stone finishes are common. The price of the panel go up significantly as the print mats are expensive to buy.
King posts need to be designed to know the steel sections size, depth the posts need to be embedded and the specification of the panel.
The post can be driven or a bore hole is excavated using an auger. The posts are then positioned and concreted in. Driven posts cannot be positioned as accurately as bored posts.
The posts holes are excavated 200mm deeper than the post. Blinding concrete is then dropped into the hole and put in to a calculated level. The post is then positioned and temporary propped. Concrete is poured into the hole and allowed to set. The temporary props can then be removed. We recommend a site engineer is available to set the post to the correct level and to make sure they are plumb.
Health & Safety Considerations (UK Construction)
Under CDM Regulations 2015, king post retaining walls require proper planning and risk control.
Key risks:
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Collapse during excavation
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Falling materials
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Working near edges
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Manual handling of infill panels
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Plant and lifting operations
Essential controls:
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Site-specific RAMS
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Temporary works design & checks
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Exclusion zones during installation
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Lifting plans for steel posts
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Competent supervision