STONE VENEER COVERAGE
About this calculator
This stone veneer calculator estimates the materials for a manufactured stone install: flats sold by the square foot, corner pieces sold by the linear foot, mortar in 80-lb bags, and metal lath in standard 27"×96" sheets. Each linear foot of outside corner replaces about 0.75 ft² of flat coverage, so the calculator deducts that to keep you from double-buying. Mortar runs about three 80-lb bags per 100 ft² with full mortar joints; dry-stack styles drop closer to one bag per 100 ft². ESTIMATE ONLY — manufacturer coverage rates vary; verify against the spec sheet for the exact product.
How to use this calculator
Enter wall length and height in feet, then subtract any window/door opening area. Add the linear feet of outside corners on the wall — corner pieces are sold separately and each lin ft replaces about 0.75 ft² of flat coverage (so the calculator deducts that to prevent double-buying).
Pick the joint style: full mortar joint is the traditional grouted look (more mortar) and dry stack is stones butted with minimal joint visible (less mortar). The result includes flats in ft², corners in lin ft, mortar bags, and metal lath sheets needed underneath.
Worked example
For a 20 × 8 ft accent wall with one 12 ft² window and 16 lin ft of outside corners, full mortar joint:
Gross area: 160 - 12 = 148 ft². Corner coverage: 16 × 0.75 = 12 ft². Flats needed: 148 - 12 = 136 ft². With 10% waste: 150 ft² of flats.
Corners with 10% waste: 18 lin ft. Mortar (full joint): ⌈148 ÷ 100 × 3⌉ = 5 bags of 80-lb Type S. Lath sheets: ⌈148 ÷ 18⌉ = 9 sheets.
At $8-$15/ft² for manufactured stone flats and $12-$25/lin ft for corners: materials run $1,200-$2,250 for stone alone. Add mortar ($35-$50), lath ($75-$120), and accessories. Total ~$1,400-$2,500 for this wall.
Dry stack on the same wall drops mortar to 2 bags (saves $14-$20) but doesn't change stone count. The look is the choice, not the cost.
Common mistakes & waste factors
Forgetting corners. Corner pieces are not the same product as flats — they're L-shaped to wrap around outside corners. Buying only flats means the corners look amateur (cut pieces don't hide the joint).
Ordering before measuring corners. The 0.75 ft²/lin ft deduction applies only to OUTSIDE corners (where two walls meet at 90°). Inside corners don't need special pieces and don't deduct.
Skipping the metal lath. Manufactured stone bonds to a scratch coat applied over metal lath. Without the lath, the stone falls off the wall within years.
Using standard mortar instead of polymer-modified. Manufactured stone needs Type S mortar with polymer additives or a dedicated stone veneer mortar. Plain Type N doesn't bond reliably to the lightweight stone.
Rules of thumb
1 lin ft outside corner ≈ 0.75 ft² of flat coverage.
Mortar: full joint = 3 bags per 100 ft²; dry stack = 1 bag per 100 ft².
Metal lath: 27"×96" sheets = 18 ft² each. 1 sheet per 18 ft² of wall.
10% waste minimum for stone — colors and shapes need selection during install.
Use polymer-modified Type S mortar or a dedicated stone veneer mortar.
Weep screed required at the bottom course on exterior installs (allows water that gets behind the stone to drain).
Common questions
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