Project measurements

Enter the project measurements and product values that control this quantity.

Total eave length receiving membrane

ft

Membrane depth up roof at eaves

ft

Total valley length

ft

Membrane width at valleys

ft

Other detail area

sq ft

Overlap / cut allowance

%

Quick values

Membrane roll width

ft

Membrane roll length

ft

Price per roll (optional)

$

Project result

Ice & Water Shield plan

Review the measured quantity, rounded purchase quantity and field-layout checks produced from the values you entered.

Planning estimate only. Verify product coverage, package size, supplier specifications and project requirements before purchasing.

Open Project Planner →

Budget scenario

Add your current local costs

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.

Currency

Supplier / material subtotal

local

Delivery / project fees

optional

Tax

%

Contingency

%

Uses the calculator's user-entered price result when one is currently shown; otherwise enter a current supplier subtotal.

Material subtotal$0.00

Delivery / fees$0.00

Tax$0.00

Contingency$0.00

Planning total$0.00

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

Formula & planning assumptions

Base membrane area

eave length × eave depth + valley length × valley width + extra area

Keeps project detail areas explicit.

Target area

base area × (1 + allowance %)

Adds overlap and cut allowance.

Rolls

ceiling(target area ÷ roll face area)

Uses entered roll dimensions.

Field verification

compare calculated quantity with measured scope and current product/stock values

Confirms the takeoff boundary before purchase or layout marks are transferred.

How to measure this project

For Ice & Water Shield Calculator, measure eave lengths and membrane depth, valley lengths and strip width, plus any separately measured detail areas; do not infer whole-roof coverage from footprint alone. Record field values before applying waste or purchase rounding, use one consistent datum and unit system, and rerun unlike conditions as separate scenarios so the result can be checked against the work area.

Before you buy materials

Before ordering, verify membrane roll coverage, lap requirements, temperature/substrate compatibility and any code- or manufacturer-required coverage zones. Use the calculator result as a planning takeoff, then reconcile whole packages or stock pieces with current product data, project documents, on-site constraints and a deliberate allowance for cuts, laps, breakage or future repair where appropriate.

Reference

Planning boundary

Item	Solved here	Verify separately
Geometry / quantity	Arithmetic from entered measurements	Field dimensions and unlike conditions
Package / stock rounding	Whole-unit purchase count when applicable	Current product package, roll or stock size
Installation requirements	Not prescribed	Manufacturer instructions, project documents and local requirements
Project scope	One entered scenario at a time	Separate unlike zones, assemblies, product systems or field conditions before combining verified totals

Start from a drawing

Roofing Takeoff Studio

Upload a plan or screenshot, calibrate one known dimension, trace the relevant geometry, and save the measured evidence before returning to this calculator for product-specific planning.

Open takeoff studio

Questions

Frequently asked questions

Are the default values a specification?

No. They are editable examples. Use the values from your measured project and the exact product or system you plan to install.

Does this tool replace product instructions or project requirements?

No. It is a planning and quantity tool. Installation sequence, suitability, fastening, structural requirements and code compliance must be verified separately.

Why does the purchase quantity round up?

Materials sold as whole rolls, bags, pieces or packages must be rounded to the next whole purchasable unit after allowances are applied.

Next step

Keep this project moving

Follow the measurement into the most useful related reference, calculator or project view.

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Ice & Water Shield Calculator: Eaves, Valleys & Rolls