How to build a shed base?

You need a firm, level base for your shed to ensure that it stays structurally sound – without one, doors will sag, walls will lean and it won’t last you as long. But how do you build a shed base and what should you make it from? Timber shed bases A timber shed base is made from pressure-treated timber and has metal spikes that you hammer into the ground to keep it in place. You can often buy them with your shed installation kit, but they also come separately, often in 6x4 or 7x5 sizes. To build a timber shed base, you’ll drill holes then fit screws in the timber until the entire frame is built. Remember to check it’s square, then fix L-shaped feet to the inside of the frame. If you’re putting your shed on a hard surface like concrete, this is all you need to do. If you’re putting the base on soft ground, hammer in spikes at each corner until they’re level with the top of the base, then secure the spikes to the base with screws. Then you can position the shed floor onto the base. How to build a plastic shed base A plastic shed base is a simple and quick way to build a shed base. You can lay it on level concrete or paving slabs, but adding sharp sand on top will help keep it more secure. They come in a kit containing plastic grids. To build your plastic base, first measure out the site and hammer a peg into each corner and tie with string or builder’s line. Make it slightly larger than the shed base to help with drainage. Then cut into the lawn and remove the turf, making sure it’s level. Lay down a membrane sheet and weigh it down if it’s windy. Then lay out the number of plastic grids you need, then remove the locking pins and clip all the grids together. Once they’re all connected, put the locking pins back in the centre of the grids. Put your shed floor on top and you’re done! Concrete or paved shed bases For a concrete base or a shed base made from paving slabs, you’ll need to dig a sub-base. For concrete bases, you’ll need to dig down 150mm so you can add 75mm of compact hardcore under 75mm of concrete. For paved shed bases, you’ll want it to be about 120mm deep for 50mm of compact hardcore and the paving slabs. How to build a shed base out of paving slabs Mix sand and cement together to make mortar or use a pre-mixed one Use a trowel to lay mortar for 1 slab at a time on the sub-base and lift a damp-sided slab onto the mortar, using a piece of timber and club hammer to tap the slab into position carefully. Continue to lay the first row of slabs Make equally-sized spacers in all the joints in the slabs to ensure they’re the same size, checking it’s level as you go along Next lay slabs along the two adjacent outer edges, filling in the central area row by row Leave the mortar to set according to the instructions or for at least 48 hours before filling in the joints with mortar or paving grout Building a shed base from concrete Create a wooden frame around your shed base area (also called formwork) to stop the concrete from spreading Mix pre-mixed concrete with water or use 1 part cement to 5 parts ballast Wet the sub-base using a watering can with a rose on the end Pour the concrete onto the framed base starting in one corner Push the blade of a shovel up and down in the edges of the concrete to get rid of air bubbles Use a rake to spread the concrete, leaving it around 18mm higher than the top of the frame. Work in sections of around 1-1.m2 Compact the concrete using a straight piece of timber that’s longer than the width of the base. Move the timber along the site, hitting it along at about half of its thickness at a time until the surface is evenly ridged Remove excess concrete and level the surface by sliding the timber back and forwards from the edge that you started. Fill in any depressions and repeat until even Run an edging trowel along the frame to round off exposed edges of the concrete and prevent chipping Cover the concrete with a plastic sheet raised on wooden supports to allow slow drying. Weigh it down with bricks Once the concrete is set, you can install your shed and remove the wooden frame with a crowbar Don’t fancy having a go at building a shed base yourself? Get a range of quotes from a professional and see how much it will cost.

Garden Shed in Harrow and beyond

Garden Sheds in Harrow

Garden sheds are an essential element of any practical garden space. They can offer storage for large garden tools, as well as for other tools. A generous shed could provide enough room for plant potting or a general workshop. Alternatively, a big shed could be utilised as an indoor sitting area. Garden sheds are available in a huge selection of sizes and can be specified to your particular needs, giving you complete control over the amount and position of windows, type, size and location of door, and style of roof. Garden sheds usually come in one of three materials. Wooden sheds are the common style and can be integrated well into any garden creating a natural look, particularly if the wood used for the shed is matched to neighbouring fences. Wooden sheds are still very popular, although they will need maintenance by retreating or staining the wood to protect the lifespan of the shed. Garden sheds are also manufactured from metal, which is very resilient and therefore great for storage of tools and other equipment. Metal sheds additionally require hardly any maintenance. The final material for garden sheds is plastic, which in modern examples is much more resilient than might be expected. When considering a garden shed, it's essential to ensure that you choose one that will fit in your garden space. Garden sheds will need to be placed on a flat area, and will need a base to be built as a foundation. This base could be made from either concrete, paving, gravel or a floating wooden base, but will have to be the right size for your shed and capable of supporting the weight of your shed when loaded.

Avg. price low	Avg. price low £300
Avg. price	Avg. price £438
Avg. price high	Avg. price high £545

Avg. price low

Avg. price low
£300

Avg. price

Avg. price
£438

Avg. price high

Avg. price high
£545

Garden shed pros in Harrow

Mitchell Landscaping have been established for 10 years, offering quality advice and services in landscaping, Gardening and Fencing. We pride ourselves in offering a prompt, efficient service and are always conscious of our customers needs. I alw...

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Edna B., PO7

Garden | Sheds in Waterlooville

Very knowledgeable in all aspects of garden landscaping. Very approachable manner and my Shed now has new felt roof a...

Surbiton landscaping and building services in business since 1999 very professional run, family Business that takes pride in their work

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Brenda F., KT4

Garden | Sheds in Worcester Park

I felt very comfortable with him and he seemed very efficient and he went into more depth as to how he and his men would...

Yes, it is possible to insulate a shed. You might want to do this if you’re planning on working in it during the winter. A professional will be able to help you find an insulated shed or advise you on how to insulate a shed that you already have. Always seek professional advise first before attempting to do this yourself!

You need a firm, level base for your shed to ensure that it stays structurally sound – without one, doors will sag, walls will lean and it won’t last you as long. But how do you build a shed base and what should you make it from? Timber shed bases A timber shed base is made from pressure-treated timber and has metal spikes that you hammer into the ground to keep it in place. You can often buy them with your shed installation kit, but they also come separately, often in 6x4 or 7x5 sizes. To build a timber shed base, you’ll drill holes then fit screws in the timber until the entire frame is built. Remember to check it’s square, then fix L-shaped feet to the inside of the frame. If you’re putting your shed on a hard surface like concrete, this is all you need to do. If you’re putting the base on soft ground, hammer in spikes at each corner until they’re level with the top of the base, then secure the spikes to the base with screws. Then you can position the shed floor onto the base. How to build a plastic shed base A plastic shed base is a simple and quick way to build a shed base. You can lay it on level concrete or paving slabs, but adding sharp sand on top will help keep it more secure. They come in a kit containing plastic grids. To build your plastic base, first measure out the site and hammer a peg into each corner and tie with string or builder’s line. Make it slightly larger than the shed base to help with drainage. Then cut into the lawn and remove the turf, making sure it’s level. Lay down a membrane sheet and weigh it down if it’s windy. Then lay out the number of plastic grids you need, then remove the locking pins and clip all the grids together. Once they’re all connected, put the locking pins back in the centre of the grids. Put your shed floor on top and you’re done! Concrete or paved shed bases For a concrete base or a shed base made from paving slabs, you’ll need to dig a sub-base. For concrete bases, you’ll need to dig down 150mm so you can add 75mm of compact hardcore under 75mm of concrete. For paved shed bases, you’ll want it to be about 120mm deep for 50mm of compact hardcore and the paving slabs.

How to build a shed base out of paving slabs
- Mix sand and cement together to make mortar or use a pre-mixed one
- Use a trowel to lay mortar for 1 slab at a time on the sub-base and lift a damp-sided slab onto the mortar, using a piece of timber and club hammer to tap the slab into position carefully. Continue to lay the first row of slabs
- Make equally-sized spacers in all the joints in the slabs to ensure they’re the same size, checking it’s level as you go along
- Next lay slabs along the two adjacent outer edges, filling in the central area row by row
- Leave the mortar to set according to the instructions or for at least 48 hours before filling in the joints with mortar or paving grout
Building a shed base from concrete
- Create a wooden frame around your shed base area (also called formwork) to stop the concrete from spreading
- Mix pre-mixed concrete with water or use 1 part cement to 5 parts ballast
- Wet the sub-base using a watering can with a rose on the end
- Pour the concrete onto the framed base starting in one corner
- Push the blade of a shovel up and down in the edges of the concrete to get rid of air bubbles
- Use a rake to spread the concrete, leaving it around 18mm higher than the top of the frame. Work in sections of around 1-1.m²
- Compact the concrete using a straight piece of timber that’s longer than the width of the base. Move the timber along the site, hitting it along at about half of its thickness at a time until the surface is evenly ridged
- Remove excess concrete and level the surface by sliding the timber back and forwards from the edge that you started. Fill in any depressions and repeat until even
- Run an edging trowel along the frame to round off exposed edges of the concrete and prevent chipping
- Cover the concrete with a plastic sheet raised on wooden supports to allow slow drying. Weigh it down with bricks
- Once the concrete is set, you can install your shed and remove the wooden frame with a crowbar

Don’t fancy having a go at building a shed base yourself? Get a range of quotes from a professional and see how much it will cost.

Try to put your shed in open space, away from trees, bushes and other buildings. This will help to protect it from falling branches and sap. It will also mean that you can access all sides of the shed for repair and maintenance purposes. Make sure you take a look at garden shed planning rules before you pick a final spot for your shed.

Yes, your shed does need a base. This is to give it a solid, level foundation. Open soil will not help with the longevity of the shed itself or the contents within. The best materials to use to make your shed base are concrete, natural stone or wood.

	Labour cost	£420
	Material cost	£150
	Waste removal	£30

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