Granite Stair Tread Price per Step: a Step Is Two Boards, Not a Length
Granite stair tread price per step is quoted by the step, and a step is a tread board, a riser board and two runs of edge work. Ask per metre and the factory has to convert first. Ask per square metre of tread face and about a third of the material drops out of the quote. One flight reads as three different numbers, so pin the basis before you compare.
What does granite stair tread price per step cover, and why must the metre be converted first?
A granite stair tread price per step is a price per set, not per length. A metre on a stair does not map to a single length, so the metre has to be converted before any figure appears. A step is not a distance, it is a set: one tread board, one riser board, two runs of edge work. Ask per metre and the first questions back are how many flights, and how many steps in each. Example, numbers only to show the method: one flight of 12 steps, 300mm tread depth, 150mm riser height, 1.20m clear width. Horizontal run is 12×0.30 = 3.60 m, slope length is 12×√(0.30²+0.15²) ≈ 4.03 m, exposed tread face is 12×1.20×0.30 = 4.32 m², and the set-based material is 12×(0.30+0.15)×1.20 = 6.48 m². Three numbers for one flight, so a quote without a stated basis cannot be compared with anything.
| Basis | What this flight works out to | Where the gap sits |
|---|---|---|
| Per step (tread and riser as a set) | 12 steps, 6.48 m² of material | Reference (6.48 = 12×0.45×1.20) |
| Per square metre of tread face | 4.32 m² | 2.16 m² short, a third of the material |
| Per metre of run, horizontal projection | 3.60 m | A length, not an area to compare |
| Per metre of run, slope length | 4.03 m | 0.43 m longer than the projection, 12% more |
Why is one step counted as two boards, and can the riser be dropped?
It cannot. The tread board is what people walk on, the riser board closes the height difference between two steps, and its height is the riser height itself, which sets how wide the material for that board must be. Drop the riser and you can see straight down to the mortar and the structural slab. The two boards carry a second condition: same batch, same grain. Their joint sits directly under the front edge, so even a small colour shift shows as a dark-to-light line when you look up from the bottom of the flight. When a quote is given per step, ask whether the riser is inside that price and what height it assumes. Quotes based on exposed tread area alone usually leave the riser out, and that is where the shortfall starts. The two numbers belong together on the drawing: tread depth sets the tread board width, riser height sets the riser board width, and with only one of them the factory can do nothing but assume a standard detail.
Why shouldn't the front edge be written off as one line of edge work included?
The front edge is the item that moves most in a step price, and the labour between one method and another differs several times over. Three things have to be written apart. Anti-slip grooves: how many, how wide, how deep, how far back from the edge. Edge work: rounded or chamfered, and whether a round is single or double, with the radius stated. Thickened nosing: a straight buildup or a duckbill, and whether the extra thickness is a glued-on strip or comes out of the slab itself. One line saying edge work included means the other side picks the cheapest method, which is a plain arris, no groove, no round. Fixing that after delivery means reworking the whole batch. On a 30mm slab, also ask where the thickness for a thickened nosing comes from.
| Front edge treatment | What is actually done | How it is measured | What the quote must state |
|---|---|---|---|
| Anti-slip grooves | Shallow grooves cut near the front edge, count set by the design | Per metre along the step width | How many, groove width, depth, distance from the edge |
| Rounded edge or chamfer | The top arris is rounded, or cut to a chamfer | Per metre | Radius or chamfer size, and whether forming and polishing are priced separately |
| Thickened nosing | The front edge is built up so it stands proud | Per metre, add-on strip listed separately | How many millimetres, and whether it is a glued strip or taken from the slab |
Why do corner steps and landing slabs always get their own line?
These pieces are not priced by the step. A step is one tread board plus one riser board, while each of these has its own shape and edge length, so a single step rate cannot cover them. A fan step is nested out of a large slab, its outer arc is longer than the inner one, and both side edges need work. The first and last steps at an angled or L-shaped turn are normally drawn from a site template. A landing slab is one large piece, its front edge treatment differs from a step, and it often needs a fall for drainage. These pieces are few, yet they are the slowest to replace: the shape needs a new layout, and a broken piece has no offcut to stand in for it. Order them as three lines, standard steps, corner steps, landing slabs, each with its own count, never as one total. Corner steps and landing slabs are priced per piece, which reconciles more easily than folding them into a step count and is easier to check on delivery.
| Which pieces carry the extra cost | Why | What to write on the order |
|---|---|---|
| Fan or curved steps | Nested from a large slab, two edges worked, shape set by the radius | Count, inner and outer arc length, radius |
| Angled or L-shaped turn steps | First and last step of the turn, drawn from a site template | Count, template or drawing number |
| Landing slabs | One large piece, different front edge, usually a drainage fall | Count, size, fall direction |
Why does a stair tread cost more than floor paving in the same granite?
Not the material, the piece count. Take the same 0.36 m² of exposed tread face. A 600×600 floor tile is laid tight to its neighbours and normally gets no edge work at all. A step 1.20 m wide and 300 mm deep also shows 0.36 m², but its front edge is worked along 1.20 m and the bottom edge of the riser along another 1.20 m, so 2.40 m in total. Same area, and the edge metres go from zero to two point four. Add the small piece size, the extra cutting, the offcuts from nesting that cannot be sold, and the packing: steps are loose pieces, the front edge needs corner protection, and a container does not reach the 346 m² slab figure. Compare step against step, not a square metre rate against a step rate. Same thickness, same stone, edge work carries more of a step price than of a floor tile, which is why a step rate reads firm.
| Compare | 600×600 floor tile | One step, 1.20 m wide |
|---|---|---|
| Exposed tread face | 0.36 m² | 0.36 m² |
| Edge metres | Zero, laid tight on four sides | 2.40 m (1.20 front edge + 1.20 riser bottom) |
| Pieces per m² of tread face | 2.78 (1÷0.36) | 2.78 steps (1÷0.36) |
Three quotes on the table, how do you line up the basis in three minutes?
Ask these five, in order, and any unanswered one is a basis that is still open. Is the riser inside this step price, and at what height. Is the price per step, per square metre of tread face, or per metre of run. Are grooves, rounds and thickening listed item by item, and which of them the step price already covers. How many corner steps and landing slabs are priced separately. Are edge metres counted on one edge or on two. Answer all five and the three quotes sit on one line, leaving variety, surface finish and lead time as the real differences. For stair work we usually run Maple Red G562 (also listed as G4562, quarried in Cenxi, Guangxi) in 30mm, cut from the same block batch and numbered by flight, MOQ 100 m², 5-day lead time.