| Surface | Length (m) | Width (m) | Qty | Area (m²) |
|---|---|---|---|---|
| Wall A | 12.00 | 3.00 | 1 | 36.00 |
| Slab Area | 8.00 | 6.00 | 1 | 48.00 |
| Beam Faces | 10.00 | 0.50 | 1 | 5.00 |
| Total | 89.00 | |||
- Coats: 2
- Porosity multiplier: 1.10
- Overlap allowance: 2%
- Coverage rate: 5.00 m²/L
- General waste: 8% + roller loss 8%
- Density: 1.20 kg/L
- Container size: 20 L
- Adjusted area: 89 × 2 × 1.10 × 1.02 ≈ 199.72 m²
- Base volume: 199.72 / 5.00 ≈ 39.94 L
- Total volume: 39.94 × 1.16 ≈ 46.33 L
- Containers: ceil(46.33 / 20) = 3
- Mass: 46.33 × 1.20 ≈ 55.6 kg
- Surface area (per row): Area = Length × Width × Qty
- Net area: Net = Total − Deductions
- Adjusted area: Adj = Net × Coats × Porosity × (1 + Overlap%)
- Base volume: Vbase(L) = Adj(m²) / Coverage(m²/L)
- Total volume with losses: Vtotal = Vbase × (1 + (Waste% + MethodLoss%) )
- Mass estimate: Mass(kg) = Vtotal(L) × Density(kg/L)
- Thickness mode: V(L) = Area(m²) × WFT(µm) / 1000, so Coverage(m²/L) = 1000 / WFT(µm)
- Select your area unit to match the takeoff.
- Add each surface as a rectangle using length and width.
- Enter coats, choose a porosity level, and set overlap.
- Choose a coverage basis: datasheet rate or target thickness.
- Set waste, pick a method, and enter density.
- Enter your container size to estimate the number of units to order.
- Press Calculate; download CSV/PDF to attach to submittals.
Coverage planning for procurement
Encapsulant takeoffs fail when coverage is treated as a single constant. This calculator separates geometry from performance so you can purchase confidently. Enter each surface as a rectangle, apply quantity, and subtract openings as deductions. Net area is expanded by coat count, a porosity multiplier, and an overlap allowance for laps and detailing. On sealed concrete, products deliver 4–7 m²/L per coat; rough masonry may fall below 3 m²/L.
Converting thickness into a coverage rate
If a datasheet specifies wet film thickness, Thickness mode converts thickness to coverage using volume conservation. The metric relationship is Coverage(m²/L) = 1000 ÷ WFT(µm). For example, 250 µm equals 4.00 m²/L, while 400 µm equals 2.50 m²/L, increasing demand by 60% at the same adjusted area. Imperial users can enter mils and get ft²/gal.
Managing losses and application effects
Loss allowances protect schedules. Mixing residue, roller loading, spray bounce-back, and touch-ups can shift totals enough to delay work. The calculator combines your general waste percentage with a method loss factor. Typical starting points are 5% for spray, 8% for roller, and 10% for brush, then adjust for complex edges, poor access, or new crews. Track actual usage by zone to refine estimates.
Packaging, logistics, and mass checks
Procurement is usually by containers, but handling depends on mass. Enter density to estimate kilograms and pounds for lifting plans and transport. As a quick check, 50 L at 1.20 kg/L weighs about 60 kg, which may require split kits or mechanical handling. Container size also affects leftover risk: smaller pails suit phased work, while drums suit production and controlled storage.
Reporting for quality control and audits
Exports create a documented record for supervisors, clients, and compliance files. The CSV captures surfaces, inputs, and totals for estimating and reconciliation. The PDF supports submittals and site briefings. If consumption differs from the estimate by more than 10%, review porosity selection, overlap, and coat count, then update the takeoff so later orders match real conditions.
FAQs
1) Should I use coverage rate or thickness mode?
Use coverage rate when your datasheet lists m²/L or ft²/gal at the target thickness. Use thickness mode when you only know wet film thickness, or when you need quick what‑if checks for different thickness targets.
2) What does the porosity multiplier represent?
It increases demand for absorbent or textured surfaces. Select a higher value for blockwork, rough concrete, or repaired areas. If the first coat soaks in heavily, raise porosity and recalculate before ordering the second batch.
3) How is total waste calculated?
Total waste equals your general waste percentage plus the selected method loss. This combined percentage is applied after the base volume is calculated, giving a practical order quantity that includes mixing, loading, and touch‑up losses.
4) Why add overlap allowance?
Overlap covers laps at joints, corners, terminations, and edge detailing. Small percentages matter on complex geometry. Start at 2% for simple slabs and increase to 5–10% for heavy cornering or multiple tie‑ins.
5) How accurate is the container estimate?
Containers are rounded up to whole units using your chosen size. If kits include separate components, order based on kit yield, not just liters. Always confirm minimum order quantities and shelf life with the supplier.
6) Can I use this for different encapsulants?
Yes. Update coverage, thickness, density, and losses to match the product and method. Keep the surface takeoff the same, then compare outputs to choose the best option for cost, handling, and application timing.