Insulation & Sealing
Plan rigid-board quantity for a measured rim-joist or band-joist strip without turning the calculator into a thermal-design tool. Measure the compatible rim run and height, subtract areas that will not receive board, then use the actual sheet dimensions and a visible cut allowance.
Change the defaults to match your project and the product you plan to buy.
Project result
Review net band area, allowance-adjusted target, whole sheets and purchased coverage.
At a glance
Planning estimate only. Verify product coverage, package size, supplier specifications and project requirements before purchasing.
Budget scenario
Use a current supplier subtotal or reuse a priced calculator result, then add optional delivery, tax and contingency. Home Measure Lab does not fetch or guess live prices.
Enter a current supplier subtotal or reuse a priced calculator result.
Budget values are local planning inputs, not live quotes. Verify tax treatment, delivery, labor and supplier pricing before purchasing.
Methodology
compatible rim run × rim height
Models only the measured band receiving rigid board.
gross rim area − excluded area
Subtract penetrations or sections that will not receive this board.
net area × (1 + cut allowance)
Keeps cutting reserve visible rather than inflating dimensions.
target area ÷ sheet area, rounded up
Uses the selected board sheet dimensions.
Measure each compatible rim-joist run along the inside perimeter and record the actual band height that will receive the selected rigid board. Add compatible runs together only when they use the same board thickness and installation approach. Measure large penetrations or blocked sections separately if they materially reduce board area; small penetrations are often better handled within the visible cut allowance than by overcomplicating the geometry.
Use the actual rigid-board sheet width and length printed for the selected product. Rigid foam and other board products may differ in thickness, facer, edge profile, fire-performance requirements and permitted exposure, so quantity does not establish suitability. Whole-sheet rounding can create useful offcuts; if the layout has many short bays, keep a modest explicit cut allowance and verify whether offcuts can be reused.
Reference
| Planning layer | Quantity basis | Keep external |
|---|---|---|
| Band geometry | run × rim height | Thermal and moisture design. |
| Exclusions | measured non-board areas | Penetration treatment. |
| Cut allowance | explicit reserve | Reuse of offcuts. |
| Purchase | whole board sheets | Product thickness and suitability. |
Questions
No. It only estimates board quantity after you select a project-appropriate product and thickness.
Usually only material exclusions that meaningfully change area need separate measurement. Smaller cuts can remain within the explicit cut allowance.
Use separate calculations when geometry or product changes materially, then combine compatible purchase quantities.
Planning guides
Insulation & Sealing
Measure compatible rim-joist runs, band height and meaningful exclusions before converting the band into rigid-board insulation area.
Read guide →Insulation & Sealing
Keep rim-joist board cuts and reusable offcuts separate from measured band area so sheet quantity remains traceable and adjustable.
Read guide →Estimate attic insulation package quantity from measured attic area, exclusions, waste allowance and product coverage per package.
Open calculator → Walls & CeilingsEstimate insulation packages from wall or ceiling area, openings, waste allowance and package coverage without selecting an R-value.
Open calculator → Insulation & SealingEstimate sealant tubes from measured joint length, entered coverage per tube and a handling or touch-up allowance.
Open calculator →