How we supply it: Granite slabs are arranged through a partner stone dealer who quotes, supplies, cuts and bills them and pays us a referral commission. Our own blue metal is crushed granite from the Perindesam deposit, but polished slabs come from dimension-stone quarries, so the dealer measures your counter or stair and cuts to it.
In one line: Granite is a hard, crystalline igneous rock of quartz and feldspar, quarried in blocks, sawn into slabs and polished for counters, floors, stairs and cladding.
Granite: the same rock, a different trade
Granite is a hard, crystalline igneous rock of quartz and feldspar, quarried in blocks, sawn into slabs and polished for counters, floors, stairs and cladding.
Our own blue metal is crushed from granite at the Perindesam deposit. Polished slabs come from dimension-stone quarries that cut sound blocks without blasting cracks into them, which is a different trade.
Thickness by use
Finishes change grip and look: polished is glossy, honed is matt, flamed and leather finishes are textured and less slippery for steps and outdoor use.
| Use | Slab thickness | Note |
|---|---|---|
| Kitchen counter | 18–20 mm | Often a doubled 40 mm front edge |
| Floors | 15–18 mm | Laid on a mortar bed or adhesive |
| Stair treads | 18–20 mm or more | Nosing edge rounded or flamed for grip |
| Window sills, thresholds | 15–18 mm | Slope sills outward |
| Wall cladding | 15–20 mm | Mechanical clamps on exteriors |
Granite, quartz or marble for a kitchen counter
| Point | Granite | Engineered quartz | Marble |
|---|---|---|---|
| Heat from vessels | Handles it well | Resin can mark under very hot pans | Handles it |
| Oil and turmeric stains | Good if dark or sealed | Very good | Poor |
| Lemon and tamarind (acid) | Resists | Resists | Etches |
| Scratch resistance | High | High | Low |
Working out the sq ft
Typical estimate: ; dealers measure the usable rectangle of each slab, so wastage depends on slab size and your layout.
- L-shaped counter, 10 ft and 8 ft arms, 2 ft deep: about 32 sq ft, buy about 38–40 sq ft with edge strips and 15–20% cutting waste
- Staircase, 12 treads of 3.5 × 1 ft: 42 sq ft, plus risers if clad
- Floors: room area plus 10% for cuts
Checks at the stone yard
- Wet the slab or view it right after washing, in daylight; cracks and patches show clearly when wet.
- Look for resin-filled fissures on the face and back; filled hairlines are common, open cracks through a counter slab are not acceptable.
- Measure thickness at several points; it should be even.
- Check polish under raking light for dull patches.
- Put a few drops of oil and water on an offcut; if they darken it quickly, the stone needs sealing.
- For one counter, take consecutive slabs from the same block so the shade matches.
Moving and storing slabs
- Store slabs on edge on an A-frame, never flat on uneven ground.
- Carry them on edge; a slab carried flat can crack under its own weight.
- Wipe cement slurry off polished faces immediately during other work.
Granite mistakes in kitchens and stairs
- Cutting sink and hob openings with no support under the narrow strips that remain.
- Overhangs beyond about 150–200 mm without brackets.
- Setting light stones on wet grey mortar that bleeds through as dark patches.
- Acidic toilet cleaners on polished granite near washbasins.
- A light, porous stone in a kitchen without sealing.