Concrete for a Shed Base
Ready Mix Concrete For Sheds Across North London & Hertfordshire
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Base Concrete
What Concrete Grade Do You Need for a Shed Base?
A shed without a solid base will not last. The ground underneath will shift over time, the structure will go out of square, doors will jam, and moisture will get in. A concrete base solves all of these problems in one pour. It keeps your shed level, keeps it dry, and gives it a surface that will outlast the building itself.
For most shed bases, C20 concrete is the right choice. It is strong enough to support the weight of a timber or metal shed, any tools or equipment stored inside, and foot traffic over many years.
If you plan to store something particularly heavy, such as a ride-on mower, large power tools, or a quad bike, you may want to consider C25 concrete. This gives you a stronger slab without a big jump in cost.
C10 or C15 are not recommended for shed bases. They are too weak for a structural slab and will crack under load over time.
For more information feel free to get in touch by filling in our from on our Contact Us page or phone us on 01442 389105 for a quote.
shed base Concrete
Finding the Right Mix for Your shed base
Concrete Grades Mixed On Site
We supply all the concrete grades listed below along with many other specialist mixes. If you need something different, just get in touch and we’ll find the right mix for your project.
Shed Concrete base
How Thick Should a Concrete Shed Base Be?
The standard thickness for a concrete shed base is 100mm (4 inches). This is suitable for most garden sheds and gives you a strong, stable slab that will not crack under normal use.
You will also need a sub-base beneath the concrete. A layer of compacted MOT Type 1 hardcore, around 75mm to 100mm thick, goes down first. This gives the concrete something firm and well-drained to sit on. Without a sub-base, the concrete can sink or crack as the ground moves.
Calculate the amount of concrete
How Much Concrete Do You Need?
Multiply length by width by depth in metres to get your volume in cubic metres.
To work out the volume of concrete you need, multiply the length by the width by the depth of your base, all in metres. This gives you the volume in cubic metres.
For example, a 3m x 2.4m shed base at 100mm (0.1m) thick needs:
3 x 2.4 x 0.1 = 0.72 cubic metres
It is a good idea to add your border allowance too. Most guidelines suggest making your base 100mm larger than the shed on each side, so factor that in when you take your measurements.
Use our concrete calculator to get an accurate figure before you call.
Get Ready to Build your shed base
What to Prepare Before the Concrete Arrives
Getting the site ready in advance makes the pour much easier. Here is what to do before we arrive:
Mark out the area
Use pegs and string to mark where the base will go. Double-check that the corners are square. Add 100mm on each side beyond the shed's footprint.
Excavate and compact
Dig out the topsoil to a depth that allows for your sub-base and concrete. Remove all grass, roots, and loose material. Compact the ground as firmly as possible.
Lay the sub-base
Spread MOT Type 1 hardcore and compact it with a wacker plate. Aim for a level, even surface.
Build the formwork
Use treated timber boards around the edge of the area to hold the wet concrete in place. Make sure the frame is level on all sides, as this determines how level your finished base will be.
Add a damp-proof membrane
Lay heavy-duty plastic sheeting over the sub-base before you pour. Turn the edges up inside the formwork to form a tray. This stops moisture rising through the slab and keeps the inside of your shed drier.
Once all of that is in place, you are ready for the concrete.
Base Concrete
Pouring and Finishing the Slab
Pour the concrete into the furthest corner of the formwork first and work towards you. Spread it evenly with a rake or shovel, making sure it fills into all the corners. Aim to pour it around 10mm higher than your formwork so there is room to compact it down.
Use a tamping board or straight-edged piece of timber to level and compact the surface. Slide it across the formwork from side to side, working out any air pockets. A smooth trowel finish is not necessary for a shed base, but a flat surface will make fitting the shed easier.
Cover the finished slab with plastic sheeting to stop it drying too quickly. Concrete that dries too fast is more likely to crack. Leave it covered and undisturbed for at least 48 hours before building on it. In cold or wet weather, allow longer.
For more information feel free to get in touch by filling in our from on our Contact Us page or phone us on 01442 389105 for a quote.
shed base Concrete
delivery of concrete
How We Deliver Concrete for Shed Bases
Shed bases are small jobs, and most concrete companies are not set up for them. They charge you for a full load whether you need it or not. We work differently.
We use volumetric mixers that carry the raw materials separately and mix the concrete fresh at your site. You only pay for what you actually use. If your base needs 0.7 cubic metres, that is all you are charged for.
If your garden has a tight driveway or a narrow access route, our mini mix lorries are the answer. They are the same size as a 6-yard skip lorry, so if a skip has reached your property before, our mini mixer will too.
If access is very difficult, such as through a side gate or down a long path, we also offer concrete pumping, which can pipe concrete directly to where it needs to go.
Use our concrete calculator to get an accurate figure before you call.
A Family Business You Can Trust
Why Choose Base Concrete?
When you need commercial concrete in London or Hertfordshire, Base Concrete offers a service you can rely on. Here is what sets us apart:
Family-Run Quality
We have been delivering concrete since 2002, building a strong reputation for helpful service and quality products. Our staff are friendly, knowledgeable and always happy to offer advice.
Volumetric Mixing Technology
Our volumetric trucks mix concrete fresh on site. This means better quality concrete, no waste, and you only pay for exactly what you use.
Clean and Tidy Service
We pride ourselves on leaving your site clean after every delivery. This is something you do not always find in our industry, but it matters to us.
Flexible Delivery Options
We have smaller lorries (the same size as a 6 yard skip lorry) for tight access, plus larger 8 metre lorries for bigger jobs. We also offer concrete pumping for difficult access situations.
Can I pour a shed base myself?
Yes. Many customers do this as a DIY project. The key is to get the sub-base right and make sure your formwork is level before the concrete arrives. Our team can advise you over the phone if you are unsure about any stage.
How long before I can build on the slab?
You can usually start building after 48 hours under normal conditions. Concrete reaches its full strength after 28 days, but it is strong enough to work on well before that.
Do I need reinforcement in a shed base?
For a standard garden shed, reinforcement is not usually needed. If you plan to park a vehicle on the slab, or if the ground conditions are poor, a layer of steel mesh can add extra strength.
What if my garden has difficult access?
Our mini mix lorries handle tight spaces well. For very restricted access, our concrete pump service can pipe concrete over fences, through gates, and along paths up to 100 metres or more.
How do I work out how much concrete I need?
Multiply length by width by depth (all in metres). Use our concrete calculator for a quick and accurate answer.
Getting Answers to Common Questions
Common Questions About Shed Base Concrete
Answers to the things customers ask us most often.
Ready Mix Concrete
Our ready mix concrete is available in standard 8 cubic metre lorries or our smaller Mini Mix lorries carrying 4.5 cubic metres for sites with limited access.
Domestic Concrete
From shed bases to patios, we help homeowners and DIY enthusiasts complete their garden and home improvement projects with quality concrete and friendly advice.
Commercial Concrete
We supply concrete for businesses and contractors working on commercial projects across North London and Hertfordshire, with flexible delivery options to suit your schedule.
Base Concrete
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We specialise in ready-mixed concrete for commercial and DIY customers alike, in all surrounding areas of North London.
Service Areas
Locations We Cover
We deliver to all the areas listed below and many more surrounding towns and villages. If you don’t see your location, just give us a call, and we’ll let you know if we can help.