Leading manufacturer and supplier of ready mix concrete, liquid screed and concrete pumps for the South West

Types of Concrete Mix and Their Uses

 

Concrete comes in many different forms, but can broadly be sorted into four categories: standard concrete, designated concrete, designed concrete, and proprietary concrete. There are a number of different grades within these categories.

The ‘best’ concrete to buy depends on the application you plan to use it for. Choosing the correct type is important because it ensures that your new build will be hard-wearing and stand the test of time.

Wright Readymix are one of the UK’s leading concrete specialists. We supply high-quality concrete solutions to the South West of England and South Wales, including ready-mixed concrete, liquid screed, and concrete pumps. In this guide, we cover everything you need to know about the different types of concrete, including their various strengths and applications.

Standardised Concrete

 

Standardised Prescribed Concretes (SPCs) are made with a prescribed quantity of materials issued by the British Standards body.

Relatively simple mixes, they are typically used for small scale jobs and mixed on site or obtained from a supplier. They have no strength guarantee or defined quality standards. There are five types:

Also known as wet lean mix concrete, this versatile mix is commonly used for a wide variety of non-structural applications.

Strength: Estimated at 7.5N/mm2 after 28 days

Uses:

  • Drainage works
  • Backing
  • Haunching
  • Kerb bedding
  • Blinding
  • Cavity filling

A multipurpose mix used for unreinforced building and housing applications. When combined with a liquid screed finish, it is an excellent choice for house foundations and bases.

Strength: Estimated at 10N/mm2 after 28 days

Uses:

  • Foundations for houses and extensions
  • Non-structural mass concrete
  • Unreinforced strip footings
  • Footings for fence posts
  • Small bases for patios
  • Drainage works
  • Blinding

Although ST3 is unsuitable as a wearing surface, it is frequently used for light domestic applications and bases. It can be used for internal floor slabs and house floors with no permanent finish flooring.

Strength: Estimated at 15N/mm2 after 28 days

Uses:

  • Foundations for sheds, garages, greenhouses, and walls
  • Paving for patios
  • Trench filling
  • Blinding house floors

ST4 can be used as a wearing surface for light foot traffic. It is used for a range of domestic, industrial, and agricultural applications.

Strength: Estimated at 20N/mm2 after 28 days

Uses:

  • Drain bedding
  • Benching to chambers
  • Unreinforced garage floors
  • Workshop and shed bases
  • Internal floor slabs

ST5 can be used in domestic, commercial, and agricultural projects, but only for light foot traffic applications.

Strength: Estimated at 25N/mm2 after 28 days

Uses:

  • Foundations for columns and posts
  • Equipment storage spaces
  • Building ground floor slabs

Designated Concrete

 

Designated concretes are identified by their application, whether agricultural, industrial, or structural. They provide peace of mind that the chosen concrete will perform as needed, letting you skip the long process of specifying a designed concrete.

Providers of designated concrete must hold the appropriate level of product conformity certification, as approved by the BSI Standards Policy and Strategy Committee.

Designated concretes are sorted into General (GEN), Reinforced (RC), Foundation (FND), and Pavement (PAV) categories, each designed for a variety of applications.

General

 

GEN concrete is used for domestic and non-structural applications. It has a relatively low strength and durability level. The requirements specify a minimum quantity of cement to be included, but no water cement ratio.

Unless fully encased or covered,GEN concretes should only ever be used for internal applications.

GEN0 is a wet lean mix concrete often used in both commercial and housing projects.

Strength: Estimated at 7.5N/mm2 after 28 days

Uses:

  • Domestic foundations
  • Cavity filling
  • Mass filling
  • Kerb bedding
  • Benching
  • Haunching

GEN1 is multifunctional concrete used for general building and housing applications.

Strength: Estimated at 10N/mm2 after 28 days

Uses:

  • Foundations for conservatories, sheds, walls, and steps
  • Trench filling
  • Cavity filling
  • Mass filling
  • Blinding house floors
  • Kerbing
  • Drainage works
  • Haunching

GEN2 is perfect for domestic floors where no permanent finish will be installed, but carpeting or tiling will be.

Strength: Estimated at 15N/mm2 after 28 days

Uses:

  • Trench fill foundations
  • Foundations for conservatories, sheds, and walls
  • Unreinforced strip footings
  • Unreinforced mass concrete fill
  • Paving for paths
  • Blinding

GEN3 can be used for light duty domestic foundations and applications. It can be used for domestic garage floors and to build unembedded internal floor slabs that will be covered by tiles, carpet, or laminate flooring.

Strength: Estimated at 20N/mm2 after 28 days

Uses:

  • Foundations for houses, garages, and walls
  • Bases for driveways and sheds
  • Unreinforced bases and oversites for conservatories and greenhouses
  • Domestic garage floors (with no embedded metal)
  • Under paving for patios
  • Mass concrete fill
  • Trench fill foundations
  • Blinding

Designated Reinforced Concretes

 

Reinforced concretes are composites pre-stressed or embedded with steel. They are strengthened with added components to prevent cracking or corrosion.

Reinforced concretes have specified requirements for minimum cementitious content .and maximum water-concrete ratios. They are ideal for builds that will be exposed to highly demanding conditions.

RC25 concrete mixes can be used in parts of a building that require steel reinforcement.

Strength: Estimated at 25N/mm2 after 28 days

Uses:

  • Lightly reinforced house or garage floors
  • Foundations, footings, and basement floors
  • Bases for sheds or outbuildings
  • Infill to insulated concrete formwork located above ground

This mix is suitable for mild exposure conditions, like pavements and driveways.

Strength: Estimated at 30N/mm2 after 28 days

Uses:

  • Driveways, walkways, paths, stables, and patios
  • Internal areas for light foot and trolley traffic
  • Slabbing
  • Some reinforced foundations

RC28/35 is a strengthened concrete ideal for moderate exposure conditions.

Strength: Estimated at 35N/mm2 after 28 days

Uses:

  • External slabbing, column bases, walls, and beams
  • Garages and workshops
  • Livestock and crop storage floors
  • Piling
  • Tank fill

RC32/40 is suitable for moderate to high exposure conditions.

Strength: Estimated at 40N/mm2 after 28 days

Uses:

  • Agricultural tracks and roads
  • Floors and walls for slurry and manure storage
  • Cavity infill to reinforced masonry
  • Farmyards
  • Factory floors

RC35/45 is appropriate for high demanding exposure conditions.

Strength: Estimated at 45N/mm2 after 28 days

Uses:

  • Toppings for floors in parlours and dairies
  • Floors and walls for silage or grain stores
  • Stable floors

RC40/50 is the hardiest of reinforced concretes, making it suitable for severe exposure conditions.

Strength: Estimated 50N/mm2 after 28 days

Uses:

  • External yards
  • Heavy traffic areas
  • Stable floors
  • Toppings for floors in parlours and dairies
  • Floors and walls for silage or grain stores

Designated Paving Concrete

 

PAV1 and PAV2 concretes include freeze-thaw resistance and are intended for heavy-duty parking and drives. They are not suitable for power float finishes.

PAV1 mixes are frequently used for domestic pavement construction. They contain an additive that creates micro-sized air bubbles in the concrete, helping protect the surface from freeze-thaw cycles.

Strength: Estimated at 35N/mm2 on 28 days

Uses:

  • Domestic pavements, parking, and carports (where no de-icing salts are used)
  • Reinforced and unreinforced bases for workshops and houses
  • Reinforced and unreinforced hard standings
  • Paved areas such as walkways and patios
  • External paving
  • House driveways

PAV2 is a heavy-duty concrete suitable for commercial and industrial use. It is resistant to frost and can be used with de-icing salts.

Strength: Estimated at 40N/mm2 after 28 days

Uses:

  • Reinforced bases for commercial buildings and agricultural storage
  • Slabbing and paving with heavy vehicle and machinery traffic
  • External yards and roads subject to occasional de-icing salts
  • Heavy-duty outdoor driveways, pavements, and forecourts
  • Industrial external car parks
  • Mass concrete fills

Designated Foundation Concretes

 

As the name suggests, foundation concrete is used in foundations, specifically in those where the ground soil contains sulphates. Sulphates can cause normal concrete to soften, decay, or crack; foundation concrete is designed to withstand this deterioration.

FND2, FND3, and FND4 can be used in all types of un-reinforced foundations. Each is designed for a different soil type.

Strength: Estimated at 30N/mm2 after 28 days

Designed Concretes

 

As directed by European Standards, designed concretes are mixed to achieve a specific strength required for an application. Unlike standardised and designated concretes, they don’t specify the cement to water mix ratios.

Proprietary Concretes

 

Proprietary concretes are custom mixed by the producer for a specific application. They are used where high-performance or specific qualities are required. The producer will provide you with a performance guarantee.

 

Get a Quote From our Concrete Specialists 

 

Wright Readymix have been supplying premium concrete mixes to the South and Wales for over two decades. We can supply your project with ready-mix concrete of all types, as well as heavy-duty concrete pumps and equipment. No matter the size or scope of your project, you can rely on us for quality materials and a top-notch service.

Get a quote online or by calling us on 0117 958 2090. We’re happy to talk through your requirements and offer our recommendations on the best concrete type for your project.

Concrete Mixes FAQs

 

We suggest concrete mixes depending on application requirements and ground conditions. Contact a member of our expert team to discuss the details of your project and we will be able to suggest the best concrete mix to suit your needs.

This will depend totally on the size of your lay site. Use our useful concrete volume calculator to find out how much concrete mix you’ll require for your project.

If you do not have a credit account with us, then our preferred method of payment is by credit or debit card.

Cure time will depend on a number of factors, such as the type of concrete mix being used and external weather conditions, however, you should have at least between 1-2 hours in which to lay the mix. We will be able to advise you more accurately once we have more details, so don’t hesitate to contact us. 

All of our concrete delivery vehicles come with chutes that can deliver ready mix concrete up to approximately 2.4m away from the rear of the vehicle and 1.2m from the side. If your lay site has restricted access that would make delivery by normal means impossible, then one of our concrete pumps for hire would be able to transport the concrete to your lay site with ease.

The minimum width required for our vehicles is 2.7m or 8ft 10 inches. If you believe that entry to your site would be particularly tricky for one of our delivery vehicles, then we would be happy to arrange for one of our team to inspect your site beforehand. You can also request delivery through our mini pump, which is perfect for accessing lay sites that are too hard to navigate for larger vehicles.

If you wish to move the concrete mix yourself i.e. with a wheelbarrow or dump truck, then you should request your ready mix concrete at a lower slump. This will mean that it is drier and therefore easier to transport manually. Please let us know in advance if you wish for our concrete mixers to offload directly into your wheelbarrow, so that we can schedule appropriately.

Our delivery trucks remain on site for an allotted time of 30 minutes. If you require the delivery truck for longer than this time, then this may incur you a waiting time charge.

Yes – without tamping, vibrating, or compacting, air pockets would remain trapped inside the wet concrete mix. These air pockets could seriously weaken the overall structure of the concrete, making it weaker and less durable than it would be if the concrete was made denser. When reinforcing metal is used, this method also ensures that the concrete best bonds to the metal.

Concrete mixes can be harmful if not handled correctly. That is why we always suggest wearing the appropriate safety gear and following these guidelines when handling our ready mix concrete or liquid screed:

  • Fresh concrete or screed can cause burns to the skin and eyes, so wear protective clothing (impervious boots, goggles, gloves, long sleeves and trousers)
  • If concrete makes contact with your skin or eye, then wash it off thoroughly or rinse from your eye immediately.
  • Do not swallow. If any concrete mix is ingested, seek immediate medical advice.
  • Once finished, remove your clothing and wash it thoroughly before reuse.

     

We have a large fleet of delivery vehicles in a range of sizes and capacities (length + width + height = capacity):
6.5m + 2.5m + 4m = 4m3
7.5m + 2.5m + 4m = 6m3
8.7m + 2.5m + 4m = 7.5m3

We are the right people for you – let’s work together!
Contact us on 0117 958 2090 today to get a quote or to find out more.

News
How to Clean a Concrete Driveway & Remove Oil Stains
17th June 2026

The car is sold, moved on, or replaced, and what’s left behind is a dark patch that wasn't there before. Months later, it’s still there, slightly duller than the surrounding concrete, no matter how many times a hose has been run over it. A driveway like this is one of the first things anyone notices, whether that’s a visitor, a neighbour, or a buyer looking round a property.

The good news is that most of it comes off. A clean concrete driveway is achievable with a methodical approach, using the right method for the right stain and starting gently before working up. Anyone weighing up concrete for driveways that resists staining from the outset might find that worth a look too.

Here is what actually works, stain by stain.

Common Types of Concrete Driveway Stains

The three stains you are most likely to be dealing with are oil and grease, rust, and general dirt with moss or algae. Each behaves differently once on concrete, which affects how you tackle it.

Oil and grease are the trickiest because concrete is so porous. According to Which?, this high porosity makes concrete the hardest surface type to clean, allowing stains to work their way deep into the surface, which is why a fresh spill that looks easy to wipe up can leave a shadow behind weeks later. Rust marks usually come from metal garden furniture, tools, or a car jack left in the same spot for too long, and they tend to sit closer to the surface than oil [1].

Dirt, moss, and algae build up over time in shaded or damp areas and are mostly surface issues rather than penetration issues. Stubborn black spots from lichen that thrives in moist conditions can be more resistant and may need repeat treatment.

The driveway needs different things depending on which of these you are dealing with:

  • Oil and grease stains need to be absorbed first, then a degreaser is applied multiple times.
  • Rust marks respond well to a rust-specific remover applied directly to the mark.
  • Moss, algae, and dirt usually lift with a stiff brush, detergent, and a rinse.

How To Remove Oil Stains from Concrete

The most reliable approach to oil stains starts gently. If the spill is fresh, the first job is to stop it from spreading and soaking in further, so blot it with an absorbent material like cat litter or sawdust rather than wiping it across the surface.

For older stains, household products are worth trying before reaching for anything stronger. Squirting washing-up liquid into a bucket of warm water, pouring it onto the affected area, and scrubbing with a broom before rinsing thoroughly is a method some people swear by. Baking soda mixed into a paste and left on the stain for a few hours before scrubbing can also help draw oil out of the surface.

Why Oil Is So Hard to Shift Once It's Set In

Once oil has had time to soak into the concrete, it bonds with the material at a level a surface wipe cannot reach. A concrete-safe degreaser, applied as the manufacturer instructs and left to work before rinsing, is designed to break down oil that has penetrated rather than just sitting on the surface.

Stubborn or older stains rarely lift in one go. Repeating the treatment, sometimes two or three times over a few days, gradually draws more oil out with each application. If a small domestic patch is part of a wider project, our DIY concrete page covers what is involved in replacing a section rather than just how to clean it.

Pressure Washing Tips for Concrete Driveways

A pressure washer can help with general grime and can assist with oil and rust once the stain has already been treated, but it is not a stain remover on its own, and the wrong technique can do real damage to the surface. Getting the settings right matters more than the machine's power.

For concrete and brick, Which? recommends the following settings and technique:

  • Use a 15-degree nozzle with a pressure setting of 2,500 to 3,000 PSI.
  • Start with lower pressure and test a small area first.
  • Work in a consistent sweeping motion, taking care around softer or damaged bricks.

Pressure washing is most useful as a finishing step, after a degreaser or detergent has already broken down the stain. Used that way, it rinses away loosened dirt and residue without forcing reliance on raw pressure to shift the mark itself [2].

What to Avoid When Cleaning Concrete

A few common habits cause more harm than the stain they are meant to fix, and it is worth knowing what they are before you start. The following three mistakes account for most avoidable damage:

  • Going straight to the highest pressure setting without testing a small area first.
  • Using undiluted bleach or strong acidic cleaners, which can etch the surface.
  • Holding the lance too close can dislodge mortar and let weeds establish.

If a cleaned patch ends up looking lighter, rougher, or more porous than the rest of the driveway, one of these is usually the cause. At that point, the best fix is often a sealant over the whole drive to even out the appearance and protect it going forward.

Talk to the Team Before You Decide

A driveway covered in oil stains and old grime can feel like a lost cause, but most of it lifts with patience and the right order of steps. Once it is clean, sealing the surface protects against future spills and keeps the drive looking right for longer.

Wright Readymix has spent years supplying concrete for driveways and domestic projects across the South West and South Wales, and understands the wear that leads to these stains in the first place. If an existing driveway is past the point where cleaning helps, or a new one needs a mix built for durability, the team can talk through the options.

Get in touch to discuss your driveway concrete requirements or call 0117 958 2090 to speak to the team directly.

External Sources

[1] Which?, Danny Dougan, Best Patio Cleaners 2026: https://www.which.co.uk/reviews/patio-cleaners/article/best-patio-cleaners-a8cIA3O3krKQ

[2] Which?, Manca Virant, Common Mistakes To Avoid When Using a Pressure Washer: https://www.which.co.uk/news/article/common-mistakes-to-avoid-when-using-a-pressure-washer-a6q3O7U8gTit

Read more
How to Prevent Air Pockets in Concrete Slabs & Bases
08th June 2026

A concrete slab should be a uniform mass. When air pockets in concrete disrupt that uniformity, the result is a network of weak points distributed throughout the structure. Now, these points may not show at the surface, but they will determine where the slab fails first.

What makes it frustrating is that the conditions producing voids are almost entirely within your control. Mix consistency, pour technique, vibration, and base preparation all play a part, and each is manageable with the right ready mix concrete and the right approach on site.

Here is what you need to know before your next pour.

What Causes Air Pockets in Concrete?

Air pockets, also called voids or entrapped air, form when air becomes trapped inside the concrete mix during or after the pour. Unlike air-entrained concrete, where microscopic bubbles are deliberately introduced to improve freeze-thaw resistance, entrapped air is uncontrolled and damaging.

The most common causes are:

  • Pouring concrete too quickly into the formwork.
  • Using a mix that’s too stiff to flow around the reinforcement.
  • Failing to compact or vibrate the concrete after placement.

Mix consistency matters throughout. A mix that is too dry will not move freely enough to fill the formwork, while an overly wet mix can segregate, with aggregate sinking and water rising to the surface.

Why Air Pockets Lead to Weak Concrete

Voids reduce load-bearing capacity and structural integrity. A slab with internal air pockets is not a uniform mass; it is a series of weak points connected by sound material, and under load, those weak points become the failure points.

For applications such as shed bases and driveways, surface consequences matter as much as structural ones. The Concrete Society (CS) defines honeycombing as coarse, stony areas caused by insufficient fine material, poor mixing, or formwork leakage [1].

Shallow honeycombing is mostly cosmetic, but deeper areas reduce the protection the concrete cover provides to reinforcement, and correction requires increasing the sand and cement content, along with proper mixing and compaction.

Our Newport project where concrete pumping was required in challenging site conditions shows how mix and placement decisions play out together on a real job. It’s a useful reference if you are dealing with access constraints or restricted pours.

How to Prevent Air Pockets During Pouring

Pour in layers rather than placing the full depth in one go. This gives you control and allows each layer to be compacted before the next goes in. Avoid dropping concrete from height; the further it falls, the more likely it is to segregate or trap air on impact.

It is also worth understanding the difference between entrapped air and deliberately entrained air. CS notes that air-entraining admixtures produce small, stable bubbles, mostly below 1mm in diameter, distributed uniformly through the mix to improve freeze-thaw resistance. However, for every 1% increase in air entrainment, concrete strength falls by about 5%. Uncontrolled entrapped air introduces far larger, irregular voids with none of those benefits [2].

The Role of Vibration & Compaction

Proper compaction is the most reliable way to remove entrapped air after placement. CS is clear that concrete not properly compacted will have reduced strength, increased permeability, reduced durability, and surface blemishes, including blowholes and honeycombing. Vibration works by fluidising the concrete, allowing entrapped air to rise to the surface [3].

For in-situ pours, an internal poker vibrator is the standard tool for thick sections. For smaller DIY pours, rodding (working a straight bar up and down through the mix) provides basic compaction; it is less effective than mechanical vibration but significantly better than nothing. On thin slabs, tamping with a straight edge helps consolidate the upper layer and close surface air.

Finishing Techniques to Avoid Surface Defects

The timing of finishing matters as much as the method. Bleeding occurs when mixing water rises to the surface as solid components settle, and it continues until the cement paste stiffens enough to halt the process.

CS identifies two risks with the top surface finish. If bleed water is remixed during finishing, the result is a weak top layer; therefore, finishing should wait until the bleed water has evaporated. If evaporation outpaces bleeding, plastic shrinkage cracking may occur [4].

Screeding should follow immediately after compaction; a bull float is then used in long, overlapping passes, and a broom or trowel finish is applied once the surface has lost its sheen. Avoid overworking the trowel, as it can bring fines to the surface and seal in air just below.

Practical Tips for Better Concrete Slabs

A few consistent habits reduce the risk of air pockets across most pours:

  • Check your base before the truck arrives; soft spots will not compact out.
  • Use a GEN3 or C20 for most domestic bases; stiffer mixes are harder to consolidate.
  • Have compaction equipment ready before the pour starts, not after.
  • Pour at a pace your compaction can keep up with; do not let sections outrun you.

Read the site before booking; access and slope shape how the pour runs.

These are not complicated adjustments, but they are easy to skip under time pressure. The contractors and self-builders who see consistent results are the ones who plan the pour as carefully as they plan the specification. Our testimonials reflect that, time and again, the jobs that go smoothly are the ones where preparation came first.

For projects where standard truck access is not possible, our innovative mini pump handles restricted sites where wheelbarrows cannot reach. So you can keep pour control intact even on difficult ground.

Getting Air Pockets Right Starts Before the Pour

Air pockets do not form by accident. They form when preparation is skipped, the mix consistency goes unchecked, or compaction gets rushed. The result is a slab that looks sound on the day and shows its weaknesses later. Remember, the steps in this guide need to be in place before the truck arrives, not after.

Wright Readymix supplies ready mix concrete and liquid screed to contractors and domestic customers across the South West and South Wales, from five plants with consistent mixes designed for the applications that matter on real sites. Part of The LGW Group, the team is available 24/7 to advise on specification, volume, and delivery logistics.

Call 0117 958 2090 or get in touch to discuss your pour, your mix specification, or anything else you need to get the job done properly.

External Sources

[1] Concrete Society (CS), Fingertips, Honeycombing of Concrete: https://www.concrete.org.uk/fingertips/honeycombing-of-concrete/

[2] Concrete Society (CS), Fingertips, Air-Entraining Admixtures: https://www.concrete.org.uk/fingertips/air-entraining-admixtures/

[3] Concrete Society (CS), Fingertips, Compaction of Concrete: https://www.concrete.org.uk/fingertips/compaction-of-concrete/

[4] Concrete Society (CS), Fingertips, Bleeding and Segregation: https://www.concrete.org.uk/fingertips/bleeding-and-segregation/

Read more
Are Recycled Aggregates Cheaper Than Natural Gravel?
12th May 2026

When you are planning a driveway sub-base, a garden path, or a shed base, the choice between recycled aggregates and natural gravel is one of the first decisions you will face. Both materials are widely available in the UK, but ordering the wrong one is easy to do. They look similar on a price list but behave differently on site, and specifying one where the other was needed can result in poor drainage, an unstable base, or a surface that does not meet the brief.

The cost gap between the two goes beyond the unit price. There are key differences to know:

  • Recycled aggregate is exempt from the Aggregates Levy; virgin stone is not.
  • Haulage distances for recycled material are often shorter, keeping costs lower.
  • Natural gravel delivers more consistent drainage and finish for visible surfaces.

Our bulk bag aggregates and gravels are available in 17 options, and our team are on hand to confirm the right specification before you order.

Here is what you need to know before you choose.

The Cost Difference Between Recycled & Virgin Aggregate

Recycled aggregate carries a built-in cost advantage that goes beyond the unit price. The Aggregates Levy applies to virgin quarried material, not to recycled aggregate, and, according to HM Revenue & Customs (HMRC), the current rate is £2.16 per tonne as of April 2026. That exemption is a real saving that suppliers can pass down the chain [1].

Natural gravel in bulk bag quantities usually runs between £60 and £100 per bulk bag, depending on type, delivery distance, and demand. Recycled crushed concrete comes in at lower prices, often by a meaningful margin on large volumes. Recycled aggregate is also sourced from demolition and excavation waste close to the point of use, which keeps haulage costs below those of quarried stone brought from further afield.

For a broader breakdown of what affects ready-mix pricing in the South West, our ready mix concrete prices guide covers volume, mix type, and delivery variables in detail.

How Recycled & Natural Gravel Actually Perform

Recycled aggregate performs well in structural applications, such as sub-bases, fill material, and compacted bases, but it behaves differently from natural gravel in certain conditions. For load-bearing and compaction, recycled crushed concrete is a reliable choice when properly laid and compacted. The Department for Transport's (DfT) Specification for the Reinstatement of Openings in Highways (SROH) states that recycled or primary materials, or any combination of the two, are permitted for reinstatement provided they meet the relevant performance and compositional requirements [2].

Drainage is where the two materials start to diverge, and natural gravel is the more reliable choice where free-draining performance is a design requirement. Recycled aggregate varies more in particle size and composition, so drainage rates are less uniform. Longevity follows a similar pattern. Natural gravel retains its properties over time, while recycled aggregate's mixed composition can lead to greater batch variability.

For a practical look at how recycled and natural aggregate behave on a live commercial project, our 80m3 ready mix concrete & concrete pump case study from Ferndale shows how material specification and site conditions interact on a real pour.

Matching the Right Aggregate to Your Project Type

The Environment Agency (EA) and Waste and Resources Action Programme’s (WRAP) Quality Protocol for aggregates from inert waste sets out the end-of-waste criteria that recycled aggregate must meet before it enters general construction use. Once a producer meets those criteria, the material ceases to be classified as waste and becomes a specified product on equal footing with quarried aggregate. The approved applications are wider than many buyers assume, covering sub-base, capping, general fill, pipe bedding, drainage, hydraulically bound mixtures, concrete, and asphalt [3].

Recycled aggregate is well-suited to:

  • Sub-base layers for driveways, paths, and hard-standing areas.
  • Backfill, general fill, and earthworks where a decorative finish is not required.
  • Shed bases and utility areas where the surface will be covered or concealed.

Natural gravel is the better choice when:

  • The surface will be visible, and the decorative finish matters.
  • Consistent drainage performance is a design requirement.
  • The project involves planting beds, path edging, or landscape features.

Combining both materials works well on larger projects. A recycled aggregate sub-base with a natural gravel top layer gives cost efficiency at depth and reliable performance at the surface.

If your project involves a driveway or hard-standing with a gravel surface finish, our guide to how to use bulk bag gravel for driveways to help curb appeal covers installation, depth, and material selection in full.

The Sustainability Case for Recycled Aggregate

Using recycled aggregate diverts material from landfill and reduces demand for quarried stone. Both outcomes carry real environmental weight.

Using recycled aggregate diverts material from landfill and reduces demand for quarried stone. In November 2025, Nuclear Restoration Services confirmed that over 15,000 tonnes of concrete from the decommissioned Sizewell A nuclear power station had been crushed, tested, and certified to the WRAP Quality Protocol before being transported to Sizewell C. The material is being used as a sub-base for foundation platforms, preventing 28 tonnes of CO₂ emissions and keeping almost 800 vehicle movements local [4].

For domestic and commercial projects, the principle holds at a smaller scale. Choosing recycled aggregate where performance requirements allow it reduces the extraction of virgin materials and lowers a project's carbon footprint without compromising the result. The important caveat is to source from a reputable supplier who can confirm the material meets the Quality Protocol standard, as not all recycled aggregate is equal in quality or consistency.

Three Questions to Ask Before You Order Aggregate

Before the Quality Protocol existed, recycled aggregate was difficult to specify with confidence. That has changed. There is now a clear framework for when recycled material is appropriate, how it should be sourced, and what performance to expect.

The decision comes down to three practical questions:

  • What does the surface need to do: bear load, drain freely, or finish well?
  • What volume are you ordering, and does the levy saving make a material difference?
  • Can your supplier confirm the recycled aggregate meets the Quality Protocol standard?

Wright Readymix supplies bulk bag aggregates and gravels across the South West and South Wales, with 17 aggregate options available for domestic and commercial projects. The team can advise on the right material for your application before you order, whether that is recycled crushed concrete for a driveway sub-base or natural gravel for a visible garden surface. Five concrete plants across Bristol, Avonmouth, Newport, Cheddar, and Paignton keep delivery distances short, and logistics well managed.

Call 0117 958 2090 or get in touch to discuss your aggregate requirements and arrange delivery to the site.

External Sources

[1] GOV.UK, HM Revenue & Customs (HMRC), Rates and Allowances — Aggregates Levy (2026): https://www.gov.uk/government/publications/rates-and-allowances-aggregates-levy/rates-and-allowances-aggregates-levy

[2] GOV.UK, Department for Transport (DfT), Specification for the Reinstatement of Openings in Highways (SROH) (2020): https://assets.publishing.service.gov.uk/media/6839b437210698b3364e86f7/reinstate-works-after-doing-streetworks.pdf

[3] GOV.UK, Environment Agency (EA), Waste and Resources Action Programme (WRAP), Quality Protocol, Aggregates from Inert Waste (2013): https://assets.publishing.service.gov.uk/media/65fd7426f1d3a0001132add0/CD1.Y_Quality_Protocol.__Aggregates_from_inert_waste.__End_of_waste_criteria_for_the_production_of_aggregates_from_inert_waste._WRAP_October_2013..pdf

[4] GOV.UK, Nuclear Restoration Services (NRS), Nuclear Decommissioning Authority (NDA), Sizewell a Concrete Reused at Sizewell C (2025): https://www.gov.uk/government/news/sizewell-a-concrete-reused-at-sizewell-c

Read more
Should You Put Rebar in Concrete Footings and Why?
07th May 2026

Concrete has a structural limitation that remains unchanged regardless of mix design or finish quality. It handles compression well, the downward force of load-bearing onto a footing. What it cannot resist on its own is tension. The pulling, flexing force generated by ground movement, uneven loading, and freeze-thaw cycles working on the structure from below. Without reinforcement, that tension finds the weakest point in the pour, and that point becomes a crack.

For anyone planning a deck, small extension, or outbuilding, understanding when rebar for footings is necessary and how to install it correctly removes the guesswork from a decision that determines whether the structure performs for decades or starts showing its weaknesses long before it should.

This guide covers when reinforcement is required under UK Building Regulations, how to achieve the right spacing and cover depth, and the installation mistakes most likely to cause problems on site.

What Rebar Actually Does Inside a Footing

Rebar spreads concentrated loads across the full width of a footing, preventing stress from accumulating at a single point. In a strip footing carrying a wall, that matters every time the load above is uneven, which, in practice, it almost always is. Reinforcement steel embedded in the pour also carries tensile loads, binding the footing together and preventing cracks from forming or widening underground movement or thermal stress.

Approved Document A sets out the Building Regulations framework for structural design in England. Section 2E covers foundations of plain concrete and defines the specific ground conditions under which they are permissible. Where those conditions are not met, whether due to poor ground, significant load, or stepped formations, the document directs designers to Eurocode 2 and the associated British Standards for reinforced concrete work. Plain concrete is not compliant in those situations [1].

The Ground Conditions That Make Reinforcement Necessary

Not every footing requires reinforcement. For very light structures on stable, well-draining ground, plain concrete to grade ST2 or GEN1, as referenced in Section 2E of Approved Document A, may be adequate, provided the ground meets specific conditions. There should be no non-engineered fill, no wide variation in ground conditions within the loaded area, and no weaker or more compressible ground at depth that could affect stability.

Where those conditions are not met, the case for reinforcement grows quickly. Stepped foundations must overlap by at least twice the height of the step or the foundation thickness, whichever is greater. On clay soils subject to shrinkage, foundation depth must reach at least 750mm on low-shrinkage clay and 1.0m on high-shrinkage clay, depths at which ground movement forces are significantly higher than a plain pour can reliably handle. Any project requiring Building Regulations approval should have the footing specification checked against these requirements before work begins.

Where ground conditions, load, or site complexity take the project outside the Section 2E provisions, reinforced design under Eurocode 2 applies. If you are working without a structural engineer, the safer default is to treat reinforcement as standard rather than optional. The cost of the steel is modest compared to the cost of a footing that fails.

Thermal movement and freeze-thaw cycles also affect how concrete performs over time. Our guide to is pouring concrete in winter for footings safe in the UK? covers the conditions most likely to compromise a slab or footing in cold weather.

Rebar Spacing & Concrete Cover Guidelines

Rebar placed incorrectly does little. Two measurements govern whether reinforcement actually works: spacing and concrete cover.

For typical domestic footing applications, horizontal bars are usually spaced at 200–300mm centres, with additional bars placed at right angles to form a grid where the footing is wide. Bunching bars together without adequate spacing prevents concrete from flowing through the cage and bonding correctly.

Concrete cover is the minimum thickness of concrete between the surface of the rebar and the outer face of the footing. It serves three purposes:

  • Protecting reinforcement from frost.
  • Accommodating thermal movement.
  • Preventing corrosion.

According to Designing Buildings, atmospheric carbon dioxide diffuses through concrete over time, reacting with calcium hydroxide to reduce the concrete's pH. Plain cement concrete has a pH of around 12.5, at which steel is stable. When carbonation drives pH below 11.5, corrosion becomes possible. Once steel corrodes, it expands, and the surrounding concrete spalls. For commercial foundations in typical UK ground conditions, a minimum cover of 40-50mm is standard practice, increasing where soils are aggressive or sulphate-bearing. Chairs or spacers placed under and alongside the rebar cage before pouring are the only reliable way to hold cover consistently across the full footing [2].

Getting the mix right before you pour is as important as placing the steel correctly. A guide to laying concrete yourself covers preparation, mix selection, and finishing in detail.

The Installation Errors Most Likely to Cause Footing Failure

Most footing failures involving reinforcement come down to a small number of errors rather than wrong specification. Getting the preparation right matters as much as the steel itself.

These are the mistakes worth checking before you pour:

  • Placing rebar directly on the ground eliminates cover and exposes steel to moisture from day one.
  • Using rebar too close to the footing face leaves less than 40mm cover and creates a corrosion path.
  • Omitting crossbars leaves parallel bars that distribute load in only one direction.

When combining rebar with ready mix concrete, use a mix with a maximum aggregate size of 20mm to allow concrete to flow through the cage without bridging. A slump class of S3 or S4 suits most reinforced domestic footing applications. Soil conditions are also regularly overlooked. A specification that works on firm, well-drained ground may be inadequate on clay-heavy or waterlogged sites. If ground conditions on your site are anything other than straightforward, the complete guide to concrete footings covers ground assessment in more detail, and speaking to a structural engineer before you pour is always time well spent.

Specify the Right Mix & Pour It with Confidence

Reinforcement done properly provides the structural integrity to last the life of the building above it. Position the cage correctly, hold the cover, use the right mix, and the concrete and steel work together as they should. Cut corners on any of those points, and the footing will perform below what the project demands.

Wright Readymix supplies ready mix concrete across the South West and South Wales, with mixes specified for reinforced domestic and commercial applications. With five concrete plants and a team available 24/7, the business has the capacity and experience to support projects from small self-build footings to large-scale commercial pours.

Call 0117 958 2090 or get in touch to discuss your footing mix requirements and delivery logistics.

External Sources

[1] GOV.UK, Ministry of Housing, Communities and Local Government, Ministry of Housing, Communities & Local Government (2018 to 2021), Structure: Approved Document A: https://www.gov.uk/government/publications/structure-approved-document-a

[2] Designing Buildings, The Construction Wiki, Concrete to Cover: https://www.designingbuildings.co.uk/wiki/Concrete_to_cover

Read more