THE BASICS
1. What an elastomeric does
Elastomeric coatings are thick, rubbery films that stretch across hairline cracks and shed water while letting the wall breathe. They are the standard answer for stucco, concrete block and masonry that keeps taking on water.
FIGURES
2. Coverage is much lower than paint
House paint spreads 350 sq ft per gallon; elastomerics build a membrane, and that thickness costs product — commonly 50–100 sq ft per gallon per coat depending on the system. The label's wet-film thickness is the number that matters; treat ranges as planning guides.
| Reference | Per coat | Total system |
|---|---|---|
| 75 sq ft/gal (typical mid-range) | 16 gallons | ≈ 32 gallons |
| 100 sq ft/gal (smooth surface) | 12 gallons | ≈ 24 gallons |
| 50 sq ft/gal (rough/block) | 24 gallons | ≈ 48 gallons |
Orientative planning ranges; the printed wet-film thickness of your product decides the real number.
SYSTEM
3. Two coats, usually back-to-back
Most systems call for two coats for crack-bridging performance and a waterproof film. Some specify the second coat within a recoat window; others want the first to cure. Follow your product's window — recoating outside it is a common failure point.
SHOPPING
4. Sizing the job
Measure wall area in square feet, use the low end of the coverage range on rough or bare masonry, and multiply by two coats. A 1,200 sq ft stucco exterior at 75 sq ft/gal per coat is about 32 gallons for the full system — noticeably more than repainting would take.
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