How to Build Sandstone Steps: Sizes, Materials and Step-by-Step Guide

To build sandstone steps, first work out a comfortable rise and going: most outdoor steps sit at 150–180mm high and 300–400mm deep, checked with the rule that twice the riser plus the going (2R + G) should land between 600 and 650mm. Then build each step from the bottom up on a compacted or concrete base, using sandstone blocks, solid treads or boulders.

• Comfortable riser: 150–180mm. Keep every riser in a flight the same height.
• Comfortable going (tread depth): 300–400mm or more for garden steps.
• Check rule: 2R + G ≈ 600–650mm (for example 2 x 150 + 330 = 630mm).
• Block sizes: sandstone blocks are 110mm bedwidth in heights of 100, 150, 200 and 250mm, so a 150mm block makes one riser.
• Guide prices: rockfaced blocks from $180/m² of face, sawn all round blocks from $250/m²; bullnosed treads and boulders by quote.

How high and deep should outdoor sandstone steps be?

Outdoor steps feel comfortable when they match a normal walking stride. The 2R + G rule captures this: two risers plus one going should add up to roughly 600–650mm. Lower risers need deeper treads, which is why garden steps are often shallower and longer than indoor stairs.

Riser (R)	Going (G)	2R + G	How it feels
100mm	450mm	650mm	Very gentle; good for long, low garden slopes
125mm	400mm	650mm	Relaxed garden steps
150mm	300–350mm	600–650mm	Comfortable everyday steps; matches a 150mm block
165mm	300mm	630mm	Compact flight where space is tight
180mm	300mm	660mm	Upper limit; fine for short flights

How many steps do I need?

Measure the total rise from the bottom ground level to the top ground level. Divide it by your target riser height, round to a whole number of steps, then divide the total rise by that number to get the exact riser. For example, a 750mm rise ÷ 165mm = 4.5, so use 5 risers of 150mm each. Five risers give four treads plus the top landing; at a 330mm going that is a horizontal run of about 1,320mm. If the run doesn’t fit, use fewer, taller risers or add a turn or landing.

Which sandstone should you use for steps: blocks, solid treads or boulders?

There are three common ways to build sandstone steps. Blocks give a crisp, built look and are the usual DIY choice; a solid bullnosed tread over block risers is the most finished option; boulders suit natural gardens and steep banks.

Option	How it is built	Look	DIY difficulty	Guide price
Sawn all round blocks	150mm-high blocks form each riser; three or four 110mm-wide blocks laid back to back, or a paver on top, form the tread	Crisp, formal, square edges	Moderate	From $250/m² of face
Rockfaced blocks	Same dimensions as sawn blocks with a chiselled, pitched riser face	Traditional, textured	Moderate	From $180/m² of face
Solid bullnosed treads	A single slab tread with a rounded front edge, set over block or concrete risers	Finished, architectural	Moderate to hard (heavy pieces)	By quote (stonemasonry)
Boulder steps	Large flat-topped boulders bedded into the slope, each one overlapping the one below	Natural, bush garden	Hard; usually machine placed	By quote
Split logs	300x300mm logs set partly into the slope as risers, with gravel or pavers behind as the tread	Chunky, rustic	Moderate; small machinery helps	By quote

Sawn all round blocks are diamond-sawn on all six faces, so treads are flat and joints are tight. Rockfaced blocks have the same dimensions but a hand-pitched face for a heritage look. Bullnosed stair treads are made to order through our custom stonemasonry service. Sizes, options and photos for all of these are on our sandstone steps Sydney page.

What you need to build sandstone steps

• Sandstone blocks, treads or boulders (allow 5–10% extra for cuts)
• Crushed sandstone or road base for the sub-base, and concrete for footings
• Mortar (sand and cement) or a stone-rated construction adhesive
• String lines, pegs, a spirit level or laser level, tape and a straight edge
• Plate compactor or hand tamper, shovel, rubber mallet
• Wet-cutting diamond saw, gloves, eye protection and a P2 respirator (sandstone dust contains crystalline silica, so cut wet)

How to build sandstone block steps, step by step

Step 1: Measure and set out

Measure the total rise and the space available for the run, then work out your riser and going as above. Drive a peg at the bottom and top, run a string line at finished height and mark where the front edge (nosing) of each step will sit.

Step 2: Excavate the slope

Cut the slope into a rough staircase shape, slightly deeper and wider than the finished steps. Each step needs firm, undisturbed ground or well-compacted fill under it.

Step 3: Build the bottom footing

The bottom riser carries the most load, so sit it on a concrete footing or at least 100mm of compacted crushed sandstone or road base. Check it is level side to side.

Step 4: Lay the first riser

Bed the first row of blocks on mortar, tap them down to the string line and check level along the length. Build in a slight fall to the front, around 1:100, so water runs off each tread instead of pooling.

Step 5: Backfill and compact behind the riser

Fill behind the blocks with crushed sandstone or road base in thin layers, compacting each layer. This compacted fill supports the tread and the next riser.

Step 6: Lay the tread

Either lay three or four blocks (110mm bedwidth each) back to back to make up a 330–440mm going, or bed a solid tread or 50mm paver over the riser and fill. Let a solid tread overhang the riser by 20–30mm to create a shadow line and a clear nosing.

Step 7: Set the next riser on the back of the tread

The next riser sits on the back 50–100mm of the tread below, which locks the flight together. Repeat steps 4–7 up the slope, checking every riser height with a gauge stick.

Step 8: Finish, clean and seal

Point any open joints, sponge off mortar from the faces as you go, and once the steps are dry apply a penetrating sealer. Reseal outdoors every 2–3 years and avoid acid cleaners.

How to build boulder steps

Boulder steps use large, flat-topped boulders placed one above another, each one overlapping the boulder below by 100–150mm. Start at the bottom with the largest stone bedded well into the ground, then backfill and compact behind it before placing the next. Because boulders vary, ask to hand-select pieces with flat tops at the quarry. Large stones are usually placed with an excavator; we deliver across greater Sydney, including crane-truck delivery for difficult access.

How do you make sandstone steps safe?

• Keep risers equal. A variation of more than a few millimetres between steps is a trip hazard.
• Choose a grippy surface. Use a sawn, natural split or sandblasted finish on treads rather than a honed one, and keep treads clear of moss.
• Add a handrail on longer flights. If steps are part of the main access to a house, building rules on handrails and balustrades may apply, so check with your council or certifier.
• Light them. Low-glare step lights make edges visible at night; see how many step lights you need.

How much do sandstone steps cost?

Material cost depends on the stone, the width of the steps and the number of risers. Blocks are priced per square metre of face: rockfaced from $180/m² and sawn all round from $250/m² (guide prices). Solid bullnosed treads and boulders are priced by quote. Labour often costs more than the stone on a flight of steps; landscapers and stonemasons typically quote per step or per day, so get two quotes and ask whether footings, fill and sealing are included. Finish the area around the steps with matching sandstone garden edging for a tidy look.

Get sandstone for your steps from Stone Front

We quarry, saw and split blocks, treads and boulders at Glenorie and can cut pieces to your riser and tread sizes. Send us your total rise and step width through our quote form and we will work out quantities and delivery; final pricing depends on quantity, finish and delivery.