18th Nov 2022 -

There are many uses for a new garden shed. It provides a great way to add storage space and is a means to tidy up your garage and garden. It can be a hobby room for amateur painters, or it can function as a shed or mechanical shop. A shed can be whatever you want it to be, but buying one can become very costly if it is ready-made and erected or if you have to pay someone else to build a shed for you.

The materials to build your shed do not have to be expensive - you can save a lot of money if you build your own using a shed kit and the building process can feel very fulfilling.

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Planning Permissions for Your Shed

Before starting to build a garden shed, you should call your local authority planning office to find out if you need planning permissions. Most likely you will not need these unless your shed is bigger than 30 square metres, but it is always a good idea to check before building it, so you do not risk being told later to take it down.

Shopping List for Shed Materials

You need to buy a few tools of the trade and, of course, materials for the actual build. This is a list of what you need to make a success of your DIY shed.

  • Shed kit: This is cheaper than getting one readymade. A shed construction kit should include plans for building it, walls, roof, door and windows. It typically will not include a floor or roof felt.
  • Pegs, string and tape measure: To measure out the size of the base.
  • Building sand and hardcore: For the base.
  • Concrete: Decide what size shed you want to build and buy sand and cement accordingly. A premixed dry concrete mix makes the job easier.
  • Bucket and stirrer: For mixing concrete.
  • Timber for the shed base framework: Approximately 15cm in width. This does not need to be high-quality timber as it is going to be used as a framework.
  • Timber for the shed floor: Timber for both the framework of the shed floor and floorboards, unless this is included in your kit.
  • Roof felt: Roof felt keeps the shed watertight - you need this unless it’s already included in your kit. 
  • Hammer, nails, screws, bolts and screwdriver
  • Drill
  • Spirit level
  • Ground spikes: Holds the shed frame in place.
  • Work gloves: To keep your hands protected from concrete and any wood splinters.
  • Safety goggles
  • Mortar: To support the paving slabs.

Step 1 - How to Build a Shed Base

Brown build a shed in a garden with trees and paving slabs.

Before you start to build the shed base, you want to think about the shed dimensions and where the shed goes in your garden. The dimensions of the shed base should be the same size as the shed floor, but with a concrete base, you can also make the base 25mm larger on all sides to create a slight overhang. This helps to prevent water from building up around the floor. 

Make sure the position you choose is on level ground for it to be built comfortably. If it is not level, it could cause problems over time and even high humidity and temperatures may not allow windows and doors to shut properly as the timber flexes.

Laying a Concrete Base

Make a timber frame to hold the concrete. If you are using a shed building kit, the materials for this will be provided for you. Firstly, lay out the shorter pieces of timber with the narrow side down and align them with the longer pieces to create a grid. From corner to corner, measure the diagonals for accuracy before you drill the frame together. With a ground spike for each corner, hammer into the ground until the spike top and timber frame are level and drill both together. 

Then, you need to pour concrete into the timber shed frame. You can either mix your concrete using water, sand and cement, or you can buy ready-mixed concrete for the job. Our advice is to have about 10% more concrete readily available - it is worth preparing more than you need, just in case.

Be sure to move quickly when you are working with concrete as it starts to go off two hours after mixing and wear long-sleeved clothing, safety goggles and gloves as cement can cause serious damage to your eyes and skin.

Once you are ready, start to pour the concrete into the timber shed frame and make sure the edges and corners are also covered. To remove any air bubbles that may appear, knock the sides of the timber frame with a hammer. When the concrete reaches the top, use a spirit level to check for a flat and even surface.

Building a Timber Shed Base

As an alternative, you can also create a simple timber shed base without the use of concrete by fixing the timber frame directly into the ground. With the help of a family member or friend, lift the base to where you want the shed and make sure the ground is even using a spirit level. Place a ground spike in each corner and hammer them into the ground. 

Each one should be level with the timber and you will need to screw the spikes to the wood. To help keep the shed level, two L-shaped plates for all corners should be installed and screwed to the timber: the first on the ground and the other against the wood. 

Using Paving Slabs for Your Shed Base

Paving slabs as a base can also do the trick for putting up your shed. Map out where you want your shed to be with wooden pegs and string, and dig approximately 120mm into the soil. This leaves enough room for the paving slabs to sit, as well as the hardcore and sand. 

Measure diagonally from each corner to check you have mapped out an equally sized space. The wooden pegs should be about 50 mm above ground, which makes them level with the hardcore. Leaving the pegs in their place, add the hardcore until it’s level with the peg tops and compact it before adding a layer of sand to fill any gaps.

Rake the surface to make sure it is level, and double-check this with a spirit level. Before laying the paving slabs, you want to hammer the four wooden pegs into the ground and lay an even layer of mortar, starting from one corner.

Place a slab from a corner and be sure it fits securely - you may want to use a mallet to gently tap the top of the slab in place. Continue this pattern and make sure there is at least a 5mm gap between each paving slab. Keep using a spirit level as you go along. 

Step 2 - Building the Shed Floor

Timber flooring build a shed with long screw.

After you have made your shed base, you are ready to start building the actual shed. If you have laid a concrete base, you should wait for the concrete to dry for at least three days. You might want to enlist the help of a friend or a family member for this task as you will probably need help lifting panels into place.

You do not need a wooden shed floor unless you want one. It depends on what you want to use the shed for. If it is going to be a tool shed or used for garden equipment, you are probably better off only having a concrete floor. 

However, if you want a shed floor made out of wood, here is a brief guide on how to make it. First of all, make a frame for the floor using timber skids and rim joists. Lay flat on the ground to form a basic outline. Make sure you have enough cross joists to make the frame solid. Then you nail the floorboards to this framework using a hammer and nails. This framework now forms the floor of the shed on which you can build the frame of the shed.

To fix the walls of the shed to the floor, it is advisable to fix pressure-treated timber plates to the concrete base using anchor bolts. When you come to erect the shed walls, you can screw them in through this plate.

Step 3 - Building the Walls of the Shed

A shed plan will usually tell you how to build the walls of the shed. Frames are generally constructed in a specific order – back wall, front wall and sidewalls. You build the framework from the floor up in that order. If you have bought a shed kit, you should have readymade walls available, which should consist of four wall sections.

These sections should fit easily together. Start by standing one of the long sections and one of the short sections next to each other on the shed floor and use bolts and screws to fix them together. Then add the other two sides. Once the four sides of the shed are up, make sure they are looking straight and level before screwing them into the floor (or wall plates if you have not made a wood floor).

Step 4 - Building the Shed Roof

If you are following a shed plan, framing the roof is one of the more critical stages of a shed build. You need a solid and sturdy roof to withstand harsh weather. With this in mind, make sure you work slowly and meticulously following the plans.

The roof usually comes in two sections when you buy a shed kit. Fit one section at a time before screwing the two sections together. Roof felt, which is waterproof and will protect your shed from the elements, should also be included in your shed kit. But if you have to buy this separately and cut it to size yourself, be sure to add 5cm to the edges and 7.5cm to each gable end.

When it comes to attaching the felt, it is best to start at the bottom edge and work your way upwards. At 10cm intervals, you will need to hammer nails through the top edge, starting at the centre before securing the edges. Make sure to pull the felt tight as you go along. Once you reach the bottom edge, increase the intervals to 30cm before you hammer the nails.

For the shed corners, it is a good idea for a friend or family member to help you as this part can prove challenging and fiddly. Fold each corner and hammer it into place, before creating a slit at the roof’s apex. The felt at the gable ends should then be folded and hammered into place, leaving 10cm gaps.

Step 5 - Finishing Touches on Your Shed

Build a shed outside with garden rake and trees.

After erecting the walls and the roof, fit the windows, door and any trim you might have (window ledges etc). You may want to consider adding gutters to the roof to collect rainwater and avoid water damage on the shed walls. Not only can water cause considerable damage to timber but the shed’s strength and durability will also be affected. If it is severe, the rain can cause the timber to rot.

Installing plastic (UPVC) guttering is the easier and cheaper option and has the added benefit of being lightweight. If you however decide on the more expensive option to install metal guttering, you can expect better strength and durability. With some light maintenance, metal guttering can last up to 25 years. 

You should also consider painting the shed to protect it further and to create a unique appeal. Before picking out a colour scheme, we recommend you varnish the timber to further protect it from tough weather conditions and other factors such as mould, fungi and algae. 

Perhaps you are using your shed as a workshop and you have thought about some tool shed ideas? Consider some simple DIY by adding a few shelves to tidy up the space. This will create a nice feature as well as free up some floor space for larger tools and materials. You could even add climbers to the exterior of your shed to grow plants such as ivy, jasmine or honeysuckle.

Easy-To-Build Shed Kits Across the UK

Building Materials Nationwide offers a wide range of garden buildings, from sheds and workshops to summer houses, including the tools you need to get the job done. If you are planning on building your shed, our knowledgeable trade experts can help you every step of the way.

By signing up for a trade account, you get access to your dedicated trade account manager. They will help you source all the building materials and tools you need and get them all delivered. Give us a call, send us an email to get started, or sign up for a trade account online today.