Question 1

What does a granite column price per meter cover, and which metre are you measuring?

Accepted Answer

A granite column price per meter only lines up once you know which metre is being priced. The shaft is quoted in square metres of arc panel, you ask per linear metre of height, and the difference between the two is π × diameter. One linear metre of height needs arc panel equal to the circumference of the column: 0.94 m² at 300 mm outside diameter, 3.14 m² at 1,000 mm, more than three times as much for the same metre. Give all four columns of the table together. Outside diameter fixes the area, inside diameter fixes the wall, weight fixes loading and lifting. Inside diameter is the outside diameter minus two 30 mm walls. Send the outside diameter alone and the reply can only be a question about wall thickness.

Question 2

Why does doubling the diameter also double the price of a metre?

Accepted Answer

One linear metre of height consumes the circumference, not the diameter. Arc panel area is π multiplied by the outside diameter and by one metre, so doubling the diameter doubles the area: 1.26 m² per metre at D400 and 2.51 m² at D800, exactly twice at the same rate. A single question about price per metre therefore cannot compare a 400 mm column with an 800 mm column. Two suppliers may each answer on their own diameter and neither need be wrong. The action is simple. When you ask per metre, put the outside diameter and the total height into the enquiry so both replies use the same diameter. Diameter is the one number a column quotation cannot drop. Drop it and comparison turns into guesswork.

Question 3

Beyond the shaft, what else is paid for on one column?

Accepted Answer

Three accounts sit outside the shaft: the capital at the top and the base at the foot, priced per piece; surface finish, priced by process; and grooving and moulding, billed per metre or per piece. The capital and the base are two pieces but one account, because their shape and carving work do not scale with height. Polished, flamed and bush-hammered cost differently on the same metre. Ask for four lines: shaft per metre, capital per piece, base per piece, finish and moulding. State the part we handle up front. Our slabs come from our own quarry in Cenxi: 30 mm Sanbao Red, cut to size, priced by the square metre, 100 m² minimum, 5 days to ship. Bending shaft panels into an arc and carving the capital and base go to a processing partner, and whether they can do it and down to what minimum diameter is one of the first things to check when choosing a supplier.

Question 4

Hollow shaft against solid shaft: how many times more stone does solid take?

Accepted Answer

On the same 30 mm wall, a hollow shaft is built from arc panels while a solid shaft is cut out of a block, so the difference is measured in cubic metres. At 400 mm outside diameter, one metre of solid column takes 0.126 m³ and weighs 339 kg, against 102 kg for hollow arc panels. At 800 mm, solid weighs 1,357 kg against 204 kg. The multiplier equals the outside diameter divided by four times the wall thickness, so the larger the diameter, the more stone solid construction eats, and the more a hollow dry-fixed build pays off. Loading follows the same logic. A 20 ft container holds 346 m² when counted by area, while a solid column can only be counted by weight, so how many fit has to be weighed first.

Question 5

How many pieces make up the shaft, and what does the piece count change?

Accepted Answer

The shaft is built from curved pieces, and the piece count sets the chord length and the arc height of each one. At 600 mm outside diameter, four pieces give a chord of 424 mm and an arc height of 88 mm, so each piece needs a slab at least 424 mm wide. Eight pieces bring the chord down to 230 mm, which eases the width, but doubles the number of joints. Chord length is the outside diameter times sin(180° ÷ number of pieces), and arc height is the radius times one minus cos(180° ÷ number of pieces). Fewer pieces mean each one is wider and more sharply curved, which puts more demand on slab width and on the bending equipment. More pieces mean more vertical joints around the ring, harder joint alignment and colour matching, and more chipping risk in transit. The count is therefore not a workshop habit; it is calculated together with slab width, joints and lifting.

Question 6

Which items must a quotation fix before the word metre stops confusing you?

Accepted Answer

Fix seven items in writing: outside and inside diameter, wall thickness, number of pieces, how the height is split into lifts, surface finish, whether capital and base are included, and whether the area is net face area or cutting area. Leave item seven blank and nobody owns the wastage: net area is what you see once installed, cutting area is what leaves the slab, and the difference is wastage. Converting your quantity into column height makes the conversation easier. The 100 m² minimum order comes to about 106 m at D300, 80 m at D400, 64 m at D500 and 53 m at D600. A 20 ft container of 346 m² comes to about 367 m at D300, 275 m at D400 and 184 m at D600. With columns, check first whether your total fills a container and clears the minimum. We take orders by the square metre, not by the metre.

Outside diameter	Arc panel per 1 m of height	Inside diameter (OD − 2×30 mm)	Weight per 1 m of height
300 mm	0.94 m²	240 mm	76 kg
400 mm	1.26 m²	340 mm	102 kg
500 mm	1.57 m²	440 mm	127 kg
600 mm	1.89 m²	540 mm	153 kg
800 mm	2.51 m²	740 mm	204 kg
1,000 mm	3.14 m²	940 mm	255 kg

Outside diameter	Solid, volume per metre	Solid, weight per metre	Hollow arc panel per metre	Ratio
400 mm	0.126 m³	339 kg	102 kg	3.3
600 mm	0.283 m³	763 kg	153 kg	5.0
800 mm	0.503 m³	1,357 kg	204 kg	6.7

Pieces	Chord length per piece	Arc height per piece	Vertical joints per ring
4	424 mm	88 mm	4
6	300 mm	40 mm	6
8	230 mm	23 mm	8

Item to fix	What goes wrong without it
Outside and inside diameter	The area has no defined circle and the wall cannot be checked
Wall thickness	30 mm and thinner walls get compared, so quantities do not reconcile
Piece count	Joint count and slab width stay open, so the processing cost floats
How the height is split	Cut lengths are undefined, joints and wastage cannot be costed
Surface finish	Polished and flamed get quoted at one rate, leaving nothing to inspect against
Capital and base included or not	Two pieces are missing from the rate and get added later
Net area or cutting area	The two quotations price different areas, so the rates cannot be compared