How to build garden steps
Introduction
If you want to construct garden steps that are built into an earth slope, you can use a whole range of materials - from bricks to concrete slabs, timber to gravel, and concrete to large flat stones. The design really depends on the type of material you're using, the gradient and the length of the slope.
The steps shown here are built from brick and concrete slabs. The first riser is laid on a concrete footing, while the rest of the risers are bedded directly onto the tread below. The tread lengths are all the same, but the excavation for the first step is longer than the others.
Step 1
Start by marking out your site using a builder's line and pegs. Fix two parallel lines down the length of the slope to mark the outer edge of the steps, and two more to mark the top and bottom. Use a builder's square to check that the corners form a right-angle.
Step 2
To work out how many treads and risers you need, you'll need to measure the vertical height and horizontal distance of your flight of steps. Knock in a peg to mark the back of the highest tread, then hold one end of a long spirit level (or a level and straightedge) at the top of the peg. Ask someone to help you measure the horizontal distance to the first riser, as well as the vertical distance to the ground at that point.
Step 3
Divide the vertical height by your riser height and use the tread-riser combinations chart to find the tread length you need. Strip away any turf in the marked-out area with a spade.
Step 4
Use lines to mark the back of the treads - making sure you set back an extra 50mm or so to give you enough room to work. Then roughly shape the steps with a spade. You'll need to leave enough depth beneath the concrete slab treads for 100mm of hardcore.
Step 5
Dig a trench about 125mm deep for the footing for the first riser. Drive in pegs levelled with a spirit level to mark the surface of the footing before you pour in the concrete. If you're going to have a paved surface leading to the steps, then dig a deeper footing and lay one or two courses of engineering bricks on top of it, below ground level. You'll then be able to lay your paving right up to the first riser.
Step 6
Concrete the footing, making sure the surface is level with your pegs. Then leave it to dry for 24 hours before you build on it.
Preparation
First, you need to decide on your best tread and riser combination. To work out how many risers you need, divide the vertical height of the flight by the height of your riser. Then divide the horizontal length of the flight into a suitable number of treads.
The combinations of tread and riser measurements in the table will make attractive, safe steps. You won't always be able to follow them exactly, though: you might need to shorten or lengthen your treads, cut some bricks or build up the ground to make your flight work. But you should try to follow these measurements as closely as possible when you make your calculations - and don't forget that a tread should never be less than 300mm from front to back.
| Tread length | Riser depth |
|---|---|
| 460mm | 100mm |
| 430mm | 113mm |
| 400mm | 125mm |
| 380mm | 140mm |
| 360mm | 150mm |
| 330mm | 165mm |
| 300mm | 180mm |
When you've worked out your measurements, it's a good idea to make a drawing that shows your step dimensions, as this is a useful reference while you're building your steps. And if you're using slabs that are 600mm square or bigger, make sure you have a helper - it really takes two people to lift and lay them.
Step 1
Mix a mortar using four parts sharp sand to one part cement. Build the first riser on the concrete footing using two skins of stretcher bond bricks. Remember to keep checking they're horizontal with a spirit level. Then leave the mortar to dry for two hours.
Step 2
Fill behind the riser with hardcore - it should extend beyond the back of the slab when you lay it. Then compact the hardcore with an earth rammer.
Step 3
The hardcore should rise slightly towards the back of the step. You can do this by using a spirit level and laying 10mm of shim across the front of the step.
Step 4
Lay a continuous bed of mortar on the riser and hardcore, and position the slab for the first tread on top of it. The slab should overhang the riser at the front and sides by about 40mm. Place the spirit level along the front edge to check the step is in line. If you're laying two slabs side by side, make a pointing mortar with three parts sharp sand to one part cement, and spread it on the edge of the first slab before you lay the second. This'll make it easier to fill the joints.
Step 5
Use a spirit level and 10mm shim to check the treads have a slight fall towards their front edge. Then fill all the joints with mortar.
Step 6
Next, build the next riser on the first tread. Check its depth is the same as the first, and make any adjustments to the horizontal joints. It's very easy for slight errors to occur, so it's a good idea to check each riser against the overall height of the flight. You can find this out by measuring from the top guide peg with a spirit level and tape measure. Then you can lay the slabs of the next tread.
Step 7
Carry on building the steps, checking the tread lengths are right. Then place a long spirit level or straightedge on the front edge of the treads to check they're in line. You can bank up the slope on either side of the steps with earth for planting, or you can grass it instead.
Not all steps are built into a slope: freestanding steps can be built on a flat base alongside an existing garden wall (not a house wall, for they would breach the damp-proof course). They are supported by low walls built of bricks, which also form the risers. The walls are like a series of boxes and are filled with hardcore. For a flight of up to five steps, the supporting walls can be centred on concrete footing strips. For a longer flight, you need a concrete pad under the whole structure. The brick risers can either be built up from ground level or you can lay a 100mm concrete footing at the back of each tread on built-up compacted hardcore before you lay the slab, and build the next riser on it. With brick steps parallel to a brick wall, the bricks in the risers should correspond to the bricks in the existing wall. The risers must be anchored, or toothed in, to the existing wall to make them more secure.
If you want to create free-standing steps next to a brick wall, you'll need to build them with brick and concrete and anchor them to the wall to make them secure. You could also use logs to support a single step on a gentle slope, or arrange them at intervals on a long incline.
To anchor your steps safely, you'll need to 'tooth in' the adjoining brick in every third course of the low walls that support them to the brickwork of the existing wall. To do this, cut out half a brick from the existing wall, then insert half of the adjoining brick and mortar this securely in its place. But make sure you take out all the relevant half-bricks from the existing wall before you start building your steps.
Step 1
Drill 10mm holes into the joints around the half of the brick you're removing. Then drill down the centre of the brick.
Step 2
Use a cold chisel and club hammer to take out the half-brick.
Step 3
Next, build your steps and support walls up to the level of the cavity. Spread mortar on the top of the wall and into the cavity, then fit half of the adjoining brick into it. After you've tapped it in place with the trowel handle, go on building the rest of that course of bricks and lay the tread.
A log step will blend in really well in an informal part of your garden. If you prefer, you could even use railway sleepers or sawn lengths of timber instead of logs. Choose one large log or two slimmer ones for each step (the logs shown here are 75mm in diameter). If you buy untreated softwood logs, make sure you give them a coat of wood preservative before you start.
Step 1
Excavate the ground either side of the step, roughly levelling it. Tread down the soil to compact it if you need to. Use a handsaw to cut your log (or logs) to the length you want, and paint the cut ends with wood preservative. Then lay one log in position to mark the first riser. Cut two pieces of log about 450mm long and sharpen one end of each to a point - you'll use these as stakes to hold your riser. After this, use a sledgehammer to knock in the stakes in front of the riser at either side of the step. But remember to leave them higher than the proposed depth of your riser.
Step 2
Put the next log directly on top of the first, and use a spirit level to make sure it's horizontal. Roll the logs away and adjust the earth below if you need to.
Step 3
Use the sledgehammer to knock down the stakes to the level of the riser.
Step 4
Take off the top log. Then, using a drill with a twist bit, drill pilot holes all the way through the lower log in line with the two stakes. Get a helper to hold the post steady from the other side with the sledgehammer, and knock in 125mm galvanised nails from the inside of the step to secure the bottom log to the stakes. Repeat this process with the top log.
Step 5
Pack hardcore behind the riser to form the step tread, and compact it with an earth rammer.
Step 6
Cover the hardcore with a layer of gravel and rake it level.
Reclaimed railway sleepers have a rugged, weathered finish that works perfectly with the informality of simple garden steps. Fill the excavated part of the step with stones, chippings or wood bark. You could relay the turf, but it'll probably wear away if it's used regularly. For a more hard-wearing surface, let the grass grow between loose-laid log cobbles.