Calculators/ Masonry & Aggregate/Stucco Calculator
Stucco Calculator
Stucco bags, lath and sand for a three-coat system.
Stucco Calculator
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Traditional stucco is three coats totalling about seven eighths of an inch: a scratch coat keyed into lath, a brown coat that levels it, and a thin finish. The thickness is not decorative; it is what gives the system its crack resistance and weather performance.
How this is calculated
- Net area = wall area minus openings, plus a waste allowance for the material that ends up on the ground.
- An 80 lb bag covers roughly 25 square feet at 3/8 inch. Scale that by your total system thickness.
- Metal lath comes in 27 by 97 inch sheets covering about 18 square feet after overlap. Two layers of weather barrier go behind it.
Frequently asked questions
How thick should stucco be?
Seven eighths of an inch over metal lath for a traditional three-coat system. One-coat systems run 3/8 inch but depend on a fibreglass mesh and a specific proprietary mix.
Does stucco need a weep screed?
Yes, at the base of every wall, at least 4 inches above grade. Without it, water that gets behind the stucco has nowhere to drain and rots the framing.