Beginner's guide to building a shed

With shed kits readily available to help you build your own, you could soon have an extra garden room. Follow our tips on how to choose and build a shed safely.

Beginner's guide to building a shed

Top shed building tips

  • Always build your shed on a level flooring.
  • Apply treatments and wood preservatives before you start building.
  • If security is a worry, upgrade your shed lock to one that bolts behind the door and side panel.

Choose your design
The most popular design is apex-roofed, but others are available, like flat roofed ones. Overlapping wall panels - feather or wany-edged - are cheaper, but not as weatherproof as tongue-and-grooved or shiplap. Make sure it's big enough for a variety of uses - will the door be wide enough to give easy access to bikes, wheelbarrow, etc? 2.5m x 1.8m (8ft x 6ft) is a popular size.

Choose your site
Locate your shed either in a shady part of the garden or in an area where it’s difficult to plant. If you're unhappy with its appearance, you can always camouflage it behind a trellis or grow plants around the outside. But remember you will need access all around for maintenance, such as applying weather treatments or painting.

Before you build
Before you start building the shed, apply several coats of preservative to the wood. Add at least one coat with the parts upside down to ensure the surplus runs into all the cracks. See painting exterior woodwork and metal for tips. Average-sized garden sheds don't need concrete foundations. Unless you're placing it on unstable or boggy ground, paving slabs will do. Ensure the shed walls fit together by building on a firm and level base. Check the shed size before making the base, which should be slightly narrower to ensure that dripping rain doesn’t form puddles on the floor, causing rot. To provide good drainage, add a gravel border around the edge.

Preparing the foundations
Mark out the base area before removing vegetation and a few inches of topsoil. Fill the depression with coarse sand, compress and level. Lay a line of paving slabs down one side keeping to a string line. You can lay these on blobs of 5:1 mortar. Leave slight gaps between slabs and brush in dry mortar for a sealed foundation. If the slabs are too wide, lay around the edges and fill the centre with concrete.

Assembling the shed
Your shed will contain detailed assembly instructions but consider the following tips:
After you've identified all the parts, lay the floor on the base and ensure its level and stable. If it moves up and down when you walk across it, it will do the same when the shed is fixed on top. Any differences in level can be easily solved by fixing small wedges of wood under the bearers.

Get more tips on how to assemble flat packs and get inspired by our flat pack gallery.