Restoring a flat roof with a silicone or acrylic liquid-applied coating can extend its life by 10-15 years at a fraction of the cost of a full replacement. However, under-applying the coating voids the warranty. Use this roof coating calculator to determine exactly how many gallons and 5-gallon pails you need to order to achieve the required mil thickness.
Check manufacturer specs. Silicone is often 1.5 - 2.0 gal/sq.
*This assumes a relatively smooth surface. Highly textured surfaces (like built-up gravel or corrugated metal) increase surface area and may require up to 20% more coating material.
Approx 9 pails (5 gal each) for 2 coats.
Measure or confirm the required geometric inputs before calculation.
Calculate the plan/base value from your measured inputs.
Use rise/run geometry or form-specific factors to convert to true sloped scope.
Translate outputs into practical units such as squares, pieces, or roll counts.
Verify complex intersections, accessories, and local requirements before procurement.
For complex roofs, run plane-by-plane geometry and accessory checks before final material ordering.
Most ordering mistakes happen when assumptions are mixed across units, pitch, and coverage rules. Using Roof Coating Calculator early helps align scope, quantity, and labor planning before supplier pricing or installer scheduling. This reduces reorders, avoids under-counting, and improves quote consistency.
Start with verified dimensions, run conservative waste assumptions, then compare output against product data sheets and field conditions. For cross-checks, pair this page with Elastomeric membrane roof estimator and Flat roof cost calculator.
Treat calculator output as a controlled estimate, then validate accessories, overlaps, and edge details separately. Final checks are stronger when you review assumptions with Single ply roofing cost calculator before submitting purchase orders.
It depends on the desired warranty length and surface texture. A standard application is 1.5 gallons per square (100 sq ft). For longer warranties (20+ years), manufacturers may require 2.5 to 3.0 gallons per square. For better estimating accuracy, cross-check roof area, pitch multiplier, and material quantity with your project notes, then confirm waste planning before final ordering. This keeps.
At a standard application rate of 1.5 gallons per square, a 5-gallon pail will cover approximately 333 square feet. For better estimating accuracy, cross-check roof area, pitch multiplier, and material quantity with your project notes, then confirm waste planning before final ordering. This keeps your field measurement aligned with real site conditions and reduces costly quantity revisions.
Yes, for flat roofs. Silicone is waterproof and can withstand ponding (standing) water indefinitely. Acrylic is water-based; if water ponds on it, the acrylic will re-emulsify and wash away. For better estimating accuracy, cross-check roof area, pitch multiplier, and material quantity with your project notes, then confirm waste planning before final ordering. This keeps your field measurement aligned with real.
Planning. Use outputs for budgeting and early scope, then verify dimensions and specifications before procurement. For better estimating accuracy, cross-check roof area, pitch multiplier, and material quantity with your project notes, then confirm waste planning before final ordering. This keeps your field measurement aligned with real site conditions and reduces costly quantity revisions.
Accuracy depends on input quality. Better field measurements and realistic assumptions produce better results. For better estimating accuracy, cross-check roof area, pitch multiplier, and material quantity with your project notes, then confirm waste planning before final ordering. This keeps your field measurement aligned with real site conditions and reduces costly quantity revisions.
Yes. Most roofing workflows include waste to cover cuts, breakage, and layout inefficiencies. For better estimating accuracy, cross-check roof area, pitch multiplier, and material quantity with your project notes, then confirm waste planning before final ordering. This keeps your field measurement aligned with real site conditions and reduces costly quantity revisions.
Usually no. Most projects need supporting checks for pitch, area, accessories, and costs. For better estimating accuracy, cross-check roof area, pitch multiplier, and material quantity with your project notes, then confirm waste planning before final ordering. This keeps your field measurement aligned with real site conditions and reduces costly quantity revisions.
Validate dimensions, pitch, overlaps, accessory counts, and local installation requirements. For better estimating accuracy, cross-check roof area, pitch multiplier, and material quantity with your project notes, then confirm waste planning before final ordering. This keeps your field measurement aligned with real site conditions and reduces costly quantity revisions. Recheck dimensions, product coverage, and install requirements before purchase.