How the stone veneer calculator works
Veneer stone is sold in two separate products. Flats cover the face of the wall and are priced per square metre or square foot. Corners are L-shaped pieces with one long and one short return, sold by the linear metre or foot and used on every outside edge. Because each corner piece also covers some wall face, the flat area is reduced by the corner length: about 0.75 ft² of face per linear foot of corner, or 0.23 m² per linear metre.
Flats = (length × height − openings − corners × 0.23 m²/m) × (1 + waste ÷ 100)Mortar is counted from the net wall area. The setting bed and grouted joints use the coverage per bag you enter. On framed walls a scratch coat about 13 mm (1/2 in) thick goes over the lath first; the calculator adds it using roughly 1,900 kg of dry mix per cubic metre, which is close to one 25 kg bag per square metre.
Worked example
A stone wainscot runs 6 m along a facade at a height of 1.2 m: 7.2 m² of face. Its two outside corners are each 1.2 m tall, so there are 2.4 m of corners, which replace 2.4 × 0.2286 = 0.55 m² of flats. That leaves 6.65 m², or 7.3 m² of flats and 2.6 m of corners once 10% is added for cutting. Setting mortar at 1 m² per bag needs 7.9 bags, and the scratch coat over the lath another 7.6, so buy 16 bags of 25 kg. The same job in feet, a 20 × 4 ft wainscot with 8 ft of corners, calls for 81.4 ft² of flats, 8.8 lin ft of corners and twelve 80 lb bags.
Veneer types at a glance
| Product | Thickness | Weight on the wall | How it is fixed |
|---|---|---|---|
| Manufactured (cast) stone | 3–5 cm (1¼–2 in) | usually under 73 kg/m² (15 lb/ft²) | Adhered with mortar over lath or masonry |
| Natural thin veneer, sawn back | 2–4 cm (¾–1½ in) | about 60–73 kg/m² (12–15 lb/ft²) | Adhered like cast stone |
| Full-bed natural stone | 8–15 cm (3–6 in) | 150 kg/m² (30 lb/ft²) and more | Built on a footing or ledge with wall ties |
| Faux stone panels | 2–4 cm | under 10 kg/m² (2 lb/ft²) | Screwed to battens, no mortar |
Adhered veneer is limited in weight by most codes (15 lb/ft² in the US residential code). Full-thickness stone is a load-bearing masonry job and needs its own foundation; ask a mason or engineer before planning it.
Installation details that change the numbers
- Grouted versus dry-stack. Dry-stack profiles have tight joints and use less mortar, often closer to 20 ft² per 80 lb bag; wide grouted joints use more.
- Clearance at the bottom. Manufactured stone normally stops about 10 cm (4 in) above soil and 5 cm (2 in) above paving, with a weep screed, so measure the veneer height from that line.
- Water behind the stone. On framed walls two layers of water-resistive barrier behind the lath are standard; skipping them causes rot that the stone hides for years.
- Painted or sealed masonry. Mortar will not bond to paint. Either remove it or treat the wall as a framed wall with lath and a scratch coat.
- Buy from one production run. Colour varies between batches; open several boxes and blend stones as you go.
Frequently asked questions
How much stone veneer do I need for a 10x8 wall?
An 80 ft² wall with no openings needs 88 ft² of flats with 10% waste. Each linear foot of outside corner you add reduces the flats by about 0.75 ft².
How many square feet does a linear foot of corner stone cover?
Roughly 0.75 ft² of wall face per linear foot, or about 0.23 m² per linear metre, which is why flats are reduced when corners are ordered.
How much mortar do I need for stone veneer?
For the setting bed and joints plan about one 80 lb bag per 12–18 ft², or one 25 kg bag per square metre. Over lath, a 1/2 in scratch coat adds roughly one 80 lb bag per 16 ft².
Can I put stone veneer directly on a concrete block wall?
Yes, if the block is clean, unpainted and unsealed, stones can be set directly without lath or a scratch coat. Test by splashing water: if it soaks in, mortar will bond.
What type of mortar is used for stone veneer?
Type S or type N mortar, or a polymer-modified veneer mortar, is typical. Follow the stone maker's instructions, as some products require a specific mix.
Last reviewed: 2026-09-27 · How we calculate