House Wrap Calculator
Figure out exactly how many rolls of house wrap you need before heading to the lumber yard. Enter your total wall area, subtract window and door openings, and this calculator returns the number of rolls required plus estimated material cost — with a 10% waste factor built in.
How to Calculate House Wrap Rolls Needed
Calculating house wrap quantity is straightforward once you have your measurements. Start with the total wall area: perimeter × wall height. For a 40×30 ft single-story house with 9-ft walls, that's (40+30+40+30) × 9 = 1,260 sq ft of gross wall area.
Next, subtract openings. A typical home has 8–12 windows averaging 12 sq ft each and 2–3 doors at 20 sq ft each. For our example: 10 windows × 12 = 120 sq ft + 2 doors × 20 = 40 sq ft → subtract 160 sq ft → net area = 1,100 sq ft.
Add 10% waste/overlap allowance: 1,100 × 1.10 = 1,210 sq ft needed. A standard Tyvek HomeWrap roll is 9 ft × 100 ft = 900 sq ft. So you need 1,210 ÷ 900 = 1.34 rolls → buy 2 rolls. This calculator automates all of that instantly.
House Wrap Installation: What Affects Coverage
Several factors affect how much house wrap a project actually consumes. Corner wrapping adds 1–2 ft of material at every inside and outside corner. Window and door rough openings require flashing extensions that extend 6–12 inches beyond the opening on all sides. Complex rooflines with multiple gables mean more cuts and higher waste percentage.
Two-story homes require horizontal laps where the wrap transitions floor levels. These laps must overlap by at least 6 inches and be taped to prevent wind-driven rain infiltration. On large two-story homes, waste can reach 15–20% rather than the standard 10%.
Material cost varies by brand and type. Standard Tyvek HomeWrap runs $0.10–$0.15/sq ft. DrainWrap costs $0.18–$0.25/sq ft. ZIP System sheathing with integrated WRB costs $0.60–$0.90/sq ft but eliminates a separate wrap layer. Factor in flashing tape ($0.50–$1.00 per linear foot) when comparing total installed cost.
House Wrap vs. Building Paper: Which to Use?
Traditional #15 felt building paper costs about $0.04–0.06/sq ft but tears more easily, can wrinkle when wet, and has lower perm ratings than synthetic wraps. Synthetic house wraps (Tyvek, Barricade, HouseWrap Pro) are stronger, lighter, and easier to install on windy days without bagging and tearing.
Perm rating matters for moisture management. House wrap should be vapor-permeable (rated 5–50 perms) so trapped moisture can dry outward. Vapor barriers (under 1 perm) block drying and cause rot if used in the wrong location. For most above-grade wall assemblies in mixed climates, a high-perm house wrap (10+ perms) is the right choice.
Frequently Asked Questions
How do I calculate how much house wrap I need?
Measure the perimeter of your house (in feet), multiply by the wall height to get total wall area. Subtract roughly 15 sq ft per standard window and 20 sq ft per door. Add 10% for overlap and waste. Divide by the coverage area of your chosen roll (a standard 9×100 ft roll covers 900 sq ft).
How much overlap do I need when installing house wrap?
ASTM standards and most manufacturer specs require 6-inch horizontal overlaps and 12-inch vertical overlaps at seams. On a standard house, overlaps and waste typically add 10-15% to the calculated net area. Always tape seams with manufacturer-approved flashing tape for code compliance.
What's the difference between Tyvek HomeWrap and DrainWrap?
Standard Tyvek HomeWrap is a flat weather-resistive barrier rated for general use. DrainWrap has a crinkled surface that creates a drainage plane between the wrap and cladding, reducing moisture accumulation behind vinyl or fiber cement siding. DrainWrap is recommended in high-rainfall regions or for direct-applied stucco systems.
Do I need house wrap under all types of siding?
Building codes (IRC R703.2) require a water-resistive barrier (WRB) under most cladding types including vinyl siding, fiber cement, wood siding, and stucco. Brick veneer typically uses felt or self-adhering WRB. Some integrated systems like EIFS include their own WRB — check manufacturer installation specs before skipping house wrap.
How long does house wrap last?
Quality house wraps like Tyvek are rated for 25+ years when properly installed and covered with cladding. UV exposure degrades most wraps within 90–120 days, so don't leave it exposed long-term. When replacing siding on an older home, inspect the house wrap for tears, gaps, or failed tape — damaged WRB should be replaced or patched before new siding goes on.