DIY Shed Foundation

Hello, dear fundamentt.com subscribers. Today, we’re going to learn how to build a DIY foundation for a shed. Generally, a shed isn’t just a simple outbuilding in the yard for keeping animals or storing old things; it’s a multifunctional structure. You can set up a nice workshop in a shed, build shelving for storing household supplies, or otherwise take advantage of a completely dry space located near your house. But for a shed to last its entire service life without needing monthly repairs, it requires a reliable foundation.

Types of Shed Foundations

The most common types of foundations used for building sheds are:

• – Pier foundation;
• – Screw pile foundation;
• – Strip foundation;

Each type has its own construction features and performance characteristics. However, they all share a relatively low installation cost, an inability to support truly heavy loads, and a simplified construction process that is accessible to practically anyone interested.

Required Materials and Tools

You should gather the necessary tools and equipment before starting any work. This will save you not only stress but also expensive materials, not to mention time. You may need the following:

1. – Concrete mixer;
2. – Crushed stone;
3. – Cement, sand, or a ready-made cement-sand mix from a hardware store;
4. – Bricks;
5. – Water;
6. – Metal rebar;
7. – Waterproofing material;
8. – Metal piles;
9. – Angle grinder;
10. – Boards, thin plywood, or heavy cardboard for formwork;
11. – Foam blocks;
12. – Synthetic cord;
13. – Pegs;
14. – Spirit level;
15. – Tamper;
16. – Screed;
17. – Trowel;
18. – Shovels and buckets.
19. This list is for the general case, typical for any construction project. Therefore, depending on the type of foundation chosen, it may be slightly modified and supplemented.

Pier Foundation for a Shed

The advantages of a pier foundation for a shed are obvious: it’s inexpensive and relatively easy to build yourself. However, it’s essential to strictly follow the sequence of steps.

1. You need to determine the required number and locations of the foundation piers. In the simplest case, you’ll need four piers, one under each corner. However, if you plan to build a shed with a complex layout, a pier will also be required under each corner element of the walls.

2. Next, calculate the depth of the holes for the piers. The base of the pier should be at least 15 cm below the frost line.

3. Now you can begin laying the piers. The most common material used for this purpose is ordinary brick. The bricklaying follows standard rules. A sand cushion is created at the bottom of the hole for drainage, and the bricks forming the body of the pier are laid on top of it. Since a shed rarely has significant weight, a one-and-a-half brick bond is usually sufficient. It’s important to use a running bond (overlapping the joints) to give the structure the necessary strength.

Besides bricks, you can also use concrete blocks for a pier foundation. The hole for them is dug in the same way as described above. However, the subsequent laying depends on the shape and size of the blocks used. If it’s a single, large rectangular block, you can simply place it in the hole. If the blocks are small, they are stacked on top of each other using cement mortar.

A third option for a pier foundation is an asbestos-cement pipe of a suitable diameter. It is placed in a pre-dug hole or pit, at the bottom of which a sand cushion has been laid below the frost line. Since the walls of an asbestos pipe are quite fragile, the pipe’s cavity should be filled with concrete to give the foundation the necessary strength. It’s best to add pea gravel to this concrete mix.

4. After completing the pier construction, a layer of waterproofing should be placed on top. This will protect the foundation from moisture damage.

Video – Building a Pier Foundation for a Shed

Screw Pile Foundation

Screw pile foundations were developed relatively recently, but that hasn’t stopped them from gaining considerable popularity. Their widespread adoption is due to a successful combination of low cost and high strength, even on the most unstable soils.

The installation process for a screw pile foundation is quite simple:

• – The pile is positioned vertically at the designated points;
• – Using a crowbar or a piece of pipe, the pile is screwed into the ground to the required depth.

The design of screw piles allows them to be installed by two or three people. A third person can help monitor the vertical alignment of the pile while the other two are doing the physical work. It doesn’t require immense effort, as each screw pile has sharp cutting edges at the bottom that easily cut and displace the soil. To attach a crowbar or metal pipe as a turning handle, there is a corresponding hole at the top of each pile.

Strip Foundation for a Shed

Building a strip foundation for a shed allows you to construct a fairly robust outbuilding on it, as this type of foundation can support almost any load. The construction work can be divided into several stages:

1. Marking out the dimensions of the future shed.

2. Dig a trench to a depth slightly below the frost line for your area. The width of the trench should be chosen so that after installing the formwork (made of plywood, thin boards, or heavy cardboard), there is enough space in the center for the foundation itself. For example, for a 40 cm wide strip foundation, you will need a trench that is 60-70 cm wide.

3. A cushion layer is placed at the bottom of the trench. It consists of two layers: sand on top and crushed stone at the bottom. The sand layer should be 5 cm thick, and the crushed stone layer should be 10 cm thick.

4. Build the formwork. Its height should extend 20-30 cm above ground level. This will protect the shed floor from rot. To give the formwork strength, you can install braces and supports between the walls inside it.

5. A rebar grid is placed at the bottom, and then the concrete is poured.

After the concrete has fully cured, waterproofing is laid on top of the strip foundation to protect both the foundation and the shed from moisture. If all the foundation work was carried out according to these recommendations, the shed built on it will last for many years. Thus, we have seen that anyone can build a DIY foundation for a shed; you just need a little patience.