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building concrete steps

By April 25th, 2024No Comments

Because concrete can be formed to any purpose, it is also a very good material for the risers and treads of steps.

Ordinary softwood planks were used in the construction of the steps, while pliable hardboard (masonite) was used for the pathway. The height of the risers and depth of the treads will depend on the slope of your garden.

Formwork is essential if concrete is to be laid above ground level and for steps. Various materials are available for formwork, including lumber. Old 2x4s may be used, provided they have reasonably straight edges and are rigid enough to bear the weight of the poured concrete.


Assemble a simple profile to establish how many steps will fit the slope of your garden. Decide more or less where you would like the steps to begin and end, and knock a peg into the ground at the top point and a longer post at the bottom.
2 Set a 2×4 at the base of the peg and mark the point where it meets the post positioned on the lower part of the slope. For accuracy, it is essential that the straightedge remain level, so use a spirit level to ensure you have the measurements right.
Measure the distance from the ground to the mark on the post, i.e. the total change in level. Then measure the distance between the post and the peg to establish the depth of the slope. Use these figures to decide how many steps to build.

Peg out the remaining corners of the stairway. The two new pegs should be 24 inches away from the peg and post already in the ground. Check that the outside corners are at 90°, using a steel measuring tape and the 3:4:5 method.
5 Stake out all five steps, spacing them as required. The pegs are positioned at 154-inch intervals, and the steps themselves will be 14 inches deep and 51/2 inches high. Use flour, chalk, or cement to mark the position of the treads on the ground.
6 Before excavating excess dirt, remove any turfs of grass which may be re-used somewhere else in the garden. It is not necessary to dig out all the soil. If you dig carefully, you can create a rough stairway which will be a good guide for the formwork.
7 The wood you use for the formwork must be straight, not bowed or warped, although it need not be new or clean. It is important to cut the upper edges neatly and absolutely straight as the concrete will be leveled off against the top edge of the wood.

The formwork must also conform to the dimensions of the treads and risers. Measure each piece and then nail all the pieces together, using a combination square for accuracy. If you cut the ends to form a point, it will be easier to knock them into the ground.
9 Position the formwork along the sides of the excavated staircase and knock it firmly into the ground with a club hammer. Ensure that the horizontal surfaces of the formwork remain level by checking them with a spirit level.

10 Since the formwork will be your guide for leveling the surface of the concrete, which will form the tread of the step, use a spirit level across the width of the steps to check that the sides are level with one another. Adjust if necessary.
11 It is also vital that the two pieces of formwork stand perfectly vertical. There should be a very slight slope from the back of each tread down to the front. Check all planes with a spirit level before you begin to mix the concrete.

Once the sides of the formwork are straight and secure, nail boards between them to contain the concrete which will form each of the risers. If there are any gaps at the sides, these will also have to be closed off with timber.

13 Now compact the sub-base of the steps with a punner or heavy post. If a layer of hardcore or crushed stone is to be included in the structure, it must be placed below the level of the formwork, or the loose material will be exposed once the formwork is removed.
14 Once all the formwork is in place you can mix the concrete. Choose a clean, dry, flat surface which will not result in moisture being absorbed from the mixture into the ground. Measure out the sand first and tip it out onto the mixing surface.
15 Now measure out the cement, using the same container to ensure that the proportions are correct. The ratio of cement: sand should be 1:3. Then mix the cement and sand with a spade or shovel until you achieve a consistent color.

Make a small crater in the center of the dry mixture and add water slowly. There is no need to measure the water, but it is important not to add too much or the concrete will be too liquid. Rather work gradually and add a little more once you have mixed it in.
Shovel the dry materials from the outside of the crater into the center. Take care that the water does not run out as you are mixing. Aim for a pliable mixture which is neither too watery nor too stiff. Add more water, a little at a time, if necessary.
18 Add the crushed stone to the mixture last. Measure it out in the container used for the cement and sandthen spread it evenly over the surface of the wet mixture. Continue to shovel until all materials are thoroughly combined.

19 Before you pour the concrete into the form, moisten the bare earth. This will prevent water from being absorbed from the concrete into the earth. Transport the wet concrete in a builder’s wheelbarrow and then shovel it with a spade, filling each step.
20 Cut a straight length of 2×4, just long enough to cover the width or depth of each tread. Use it to compact the concrete with a chopping movement to get rid of any air bubbles, and then level it to the upper surface of the form, using a sawing motion.
21 Allow the concrete to set thoroughly for about 24 hours before removing the shuttering. First, carefully prise the planks away from the front of each riser, using a screwdriver. Then pull the two side sections out of the ground.

22 If you wish, lay pavers over the top of the treads. First position them loosely over the concrete to see how they fit, and then mix mortar in a cement: sand ratio of 1:5. Lay them as described on page 39, using a trowel to fill the joints with mortar.
23 Once the steps are complete, you can lay the path. You will need pegs and string or a builder’s line to mark out its position. Use additional pegs where it curves, and measure the width at various points to ensure that the edges are parallel to each other.
24 Use flour or chalk to make more distinct lines on the grass, then carefully remove the turfs between them. Excavate the pathway to a depth of 4-6 inches to accommodate a 2-inch layer of gravel or crushed stone (hardcore) and 2-4 inches of concrete.

25 Compact the ground well with a punner or heavy pole and then pour in the hardcore. Distribute it evenly with a spade or rake, then compact it well. This will form the sub- base for the path, so it is vital that it is stable and there are no air-pockets.
26 Cut hardboard or any other suitable flexible material to the depth of the concrete, and nail to pegs to form shuttering. You can re-use the upright sections of the step formwork if you wish. Position the formwork and hammer it in place.
27 Make sure that the tops of both sides of the shuttering are on an even plane, allowing for a very slight drainage slope across the path. A gradient of 1:40 is ample in this context. Do not forget to use a spirit level to check the alignment.

Instead of mixing the concrete on a flat surface and then transporting it to the site, you could mix it in a builder’s wheelbarrow for convenience. Follow steps 14-18, adding a little more water if you find that the mixture is too dry.

29 Spray the compacted hardcore base lightly with water before you tip the contents of the wheelbarrow between the shuttering. Shovel it evenly, so that it completely fills the formwork next to the bottom step. Mix another batch and repeat.
Use a 2×4 to compact and level the concrete. As you chop into it, water will rise to the surface. When the concrete has set, remove the formwork. Keep the concrete moist for several days to allow it to cure, hosing it every few days if necessary.


George Gitau

Meet George, an advocate for traditional craftsmanship. I will provide you with educational content, techniques and ideas for your next garden and home improvement project. Together, let's create beautiful spaces that are not only beautiful but also functional

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