TryBuildCalcHouse Wrap Calculator (Weather-Resistant Barrier Rolls, Tape, Fasteners & Cost)
Calculate house wrap rolls, seam/flashing tape, fasteners, and cost.
🕒 Last updated: November 7, 2026
Inputs
Section 1: Wall Sections
Wall Section 1
Windows on this wall
Doors on this wall
Window and door area is fully deducted from this wall's reported Net Wrap Area, matching this category's other siding calculators — but the roll count below is computed from this wall's full gross width and height regardless, since house wrap must be bought as a continuous roll spanning the whole wall before being cut around any opening.
Each row is a separate wall elevation — up to 20 sections, combined into one total. Leave window/door counts at 0 for a blank wall.
Section 2: Roll & Overlap Settings
ℹ️One roll size is used for the whole project — real house-wrap jobs buy a single SKU, not a mix of roll widths/lengths.
ℹ️Minimum overlap between stacked courses (shingle-lap). 6 in is the most commonly cited figure across manufacturer/retail sources, though some products allow as little as 2 in — confirm your product's own install guide.
ℹ️Overlap used when splicing two rolls end-to-end along the same course. This overlap is consumed as real material wherever a course needs splicing (its length exceeds one roll), slightly increasing the piece/roll count there — it has no effect on a wall that fits on a single continuous roll.
Section 3: Fasteners
ℹ️Sets the fastener grid's horizontal spacing — confirm the required spacing for your local code/sheathing before finalizing.
ℹ️Published cap-fastener spacing varies widely by manufacturer (cited ranges run roughly 12-32 in o.c.) — confirm your specific product's installation instructions.
ℹ️Only changes the planning box size used to convert the fastener count into boxes to buy — not the count itself.
Section 4: Waste Allowance
ℹ️Applied to course length, fastener count, and flashing/seam tape length.
Section 5: Cost
Buy 1 roll(s) of house wrap
Covering 226 sq ft of net wall area across 1 wall section(s).
Area & Rolls
Net Wrap Area (openings deducted): 226 sq ft (21.0 m²)
Waste-Adjusted Net Area: 248 sq ft (+10%)
Roll Size: 9 ft x 100 ft
House Wrap Rolls Needed: 1 roll(s)
Total Courses: 1 course(s) across 1 wall section(s)
Splice Seams: 0 seam(s)
Tape & Fasteners
Seam Tape: 0 roll(s) (0 ft)
Flashing Tape (windows/doors): 1 roll(s) (52 ft)
Fasteners: 185 count, 1 box(es)
Quick Insight
Calculated across 1 wall section(s) using 9 ft x 100 ft (900 sq ft) rolls: Net Wrap Area (226 sq ft, openings fully deducted) is reported for at-a-glance comparison with this category's other calculators, but the 1 roll(s) needed come from real overlapping-course geometry laid out across each wall's FULL GROSS width and height, then bin-packed into 100 ft rolls — house wrap must be bought and installed as a continuous roll spanning the entire wall, including straight across any window or door, so deducting opening area never reduces the roll count.
Bill of Materials
Main material: 1 roll(s) + recommended tools
+−
Bill of Materials
Main material: 1 roll(s) + recommended tools
Computed items reflect your entered wall sections and roll size; consumables below are general recommendations — actual needs vary by product and site.
For Your Job
House Wrap Rolls
1 roll(s)
Find suppliersSeam & Flashing Tape
0 seam + 1 flashing roll(s)
Find suppliersFasteners
1 box(es)
Find suppliersGeneral Tools & Consumables
Corrosion-resistant cap nails or cap staples
Utility knife and straightedge
J-roller or hand pressure tool
Chalk line
Staple hammer or pneumatic cap stapler (if using cap staples)
Approximate results for planning only. Verify with a professional.
House Wrap Overlapping Courses
What Is a House Wrap / Weather-Resistant Barrier Calculator?
If you're pricing a house wrap (water-resistive barrier, WRB) job, this calculator answers how many rolls, how much seam tape and window/door flashing tape, and how many fasteners you need, from your own wall sections, window and door openings, roll size, and fastener spacing. It returns rolls needed (bin-packed from real overlapping-course geometry, not a flat area-over-coverage ratio), seam tape for every horizontal lap and vertical splice, flashing tape for openings, fastener count and boxes, and an optional material + labor cost.
It is built for homeowners, siding and WRB installers, and estimators pricing a new-construction or re-wrap job on a house with one or several distinct wall elevations, each with its own size and openings.
What makes this calculator different from a siding board takeoff:
House wrap is a continuous rolled sheet material installed in overlapping horizontal courses, not a cut-to-length board product with a panel count or exposure ratio. This calculator models the real course layout (how many courses a wall's height needs against the selected roll's width and your horizontal lap), then bin-packs every wall's actual course lengths into a shared pool of rolls — multiple walls, or multiple courses on one tall wall, can share leftover length from the same roll rather than each being rounded up independently. Window and door openings ARE fully deducted from the reported Net Wrap Area (matching this category's Stucco, Fiber Cement, and Wood Siding calculators), but the roll count itself is computed from each wall's full gross width and height — house wrap must be bought and installed as a continuous roll spanning the entire wall, including straight across any opening, before being cut and flapped into the rough opening for flashing. There is also no discrete corner accessory the way Stucco's corner bead or Fiber Cement/Wood Siding's corner boards work — house wrap simply continues or overlaps at a corner.
Applicable standards:
- IRC R703.2 requires a water-resistive barrier behind exterior wall covering, installed per the WRB manufacturer's own installation instructions — code does not itself specify a literal overlap or fastener-spacing number for plastic housewrap
- Local building code and the specific product's installation instructions may differ from the general figures used here and should always take precedence
- This calculator estimates material quantity and cost only, not structural wall design, moisture management/building-envelope performance, or an engineered flashing detail
How the house wrap calculation works
Net Wrap Area comes from gross wall area with every window and door deducted, for headline reporting — but roll count is a separate, physically grounded calculation from real course geometry across each wall's own gross dimensions.
Step 1 - Net Wrap Area (reporting) vs. gross course geometry (roll count)
Net Wrap Area = SUM(Wall Width x Height) - SUM(ALL Window Area + ALL Door Area)
Course Count (per wall) = courses needed to cover the wall's GROSS Height against the roll width and horizontal lap
REAL Splice Count (per wall) = pieces needed to cover the wall's own GROSS, un-padded Width against the roll length and vertical/end lap
PURCHASE Pieces (bin-packing pool only) = same calculation using Width x (1 + Waste % / 100)
Net Wrap Area deducts every opening, matching this category's Stucco/Fiber Cement/Wood Siding convention — but it is a REPORTING metric only. Course count, and the REAL splice count/tape reported below, always use the wall's true gross width and height — applying waste BEFORE determining splice geometry would report a splice on a wall that physically fits on one continuous roll. Waste only inflates the separate quantity actually bought.
Step 2 - Roll count, by real bin-packing
Each course's waste-inflated run length is split into roll-length pieces, each overlapping the next by the Vertical/End Lap (never a zero-overlap butt join)
ALL wall sections' purchase pieces are pooled into ONE list
Rolls Needed = near-optimal bin-packing of that pooled list into the selected roll's length
Pooling every wall's course pieces together means leftover length from one wall's course can share a roll with another wall's course, or with a second course on the same tall wall — never a flat ceil(area / roll coverage) ratio, and never assuming every course needs its own freshly-opened roll. The purchase quantity can need one more roll than the real splice geometry alone would, as a waste safety margin — see the FAQ.
Step 3 - Seam tape, flashing tape, and fasteners
Horizontal Seam Tape = SUM(Horizontal Seams per wall x Wall Width x Waste Multiplier)
Splice Tape = SUM(REAL Splice Seams per wall x Roll Width) — crosswise joint, not along the course
Flashing Tape = Total Opening Perimeter (incl. a door's own sill) x Waste Multiplier
Fasteners per Wall = (Stud Lines Across Width) x (Nail Lines Up FULL Real Height) — counted ONCE, not per course
Fastener count uses the wall's real height once, regardless of how many overlapping courses that height is built from — multiplying by course count would double- or triple-count the same studs. A door's opening perimeter runs its full 4-sided head + both jambs + sill, same as a window, since flashing tape (unlike a discrete corner/trim accessory) is applied across a door's sill too. Seam tape and flashing tape are different products tracked (and rolled up) separately, since they come on different common roll lengths.
Real-World House Wrap Calculation Example
This example uses the active calculator inputs above and follows the same steps from the formula section.
Input Values Used
| Input | Value | Why it is used |
|---|---|---|
| Wall Sections | 1 section(s) | Sums to the total Net Wrap Area (openings fully deducted) |
| Roll Size | 9 ft x 100 ft | Drives course count (via roll width) and roll bin-packing (via roll length) |
| Horizontal Lap | 6 in | Reduces each course's effective coverage height, increasing course count on tall walls |
| Waste Allowance | 10% | Added to course length, fastener count, and tape length |
Step 1 — Net Wrap Area & Roll Count
| Calculation | Formula / Substitution | Result |
|---|---|---|
| Gross area minus every window/door (reporting only) | 270 sq ft - 44 sq ft | 226 sq ft Net Wrap Area |
| Waste-adjusted Net Wrap Area (for labor cost) | 226 x (1 + 10/100) | 248 sq ft |
| Rolls needed (from GROSS wall geometry, not net area) | Bin-packed course pieces across 1 course(s) | 1 roll(s) |
Step 2 — Seam & Flashing Tape
| Calculation | Formula / Substitution | Result |
|---|---|---|
| Seam tape (horizontal lap + splice) | CEIL(0 ft / 165 ft) | 0 roll(s) |
| Flashing tape (windows/doors) | CEIL(47.6 ft x waste / 75 ft) | 1 roll(s) |
Step 3 — Fasteners
| Calculation | Formula / Substitution | Result |
|---|---|---|
| Fastener grid (stud lines x nail lines, waste-adjusted) | 16 in O.C. framing x 18 in O.C. vertical | 185 count |
| Fastener boxes | CEIL(185 / 3500) | 1 box(es) |
Therefore, for this job you need 1 house wrap roll(s), 0 seam tape roll(s), 1 flashing tape roll(s), and 1 fastener box(es).
Essential Checklist+−
Complete these critical checks before approving the work or proceeding to the next construction stage.
✓Measurement & Takeoff+-
- Every wall section's width and height were measured on site, not estimated from a floor plan alone.
- Window and door counts and typical sizes were recorded for each wall section that has openings, not assumed uniform across the whole house.
- Roll size selected matches the actual product being purchased, not left at the default without checking the supplier's catalog.
✓Roll & Overlap Planning+-
- Horizontal (course-to-course) lap overlap matches the specific house wrap product's own installation instructions, not assumed from this calculator's default alone.
- Roll count for ordering includes this calculator's waste allowance, not the raw unadjusted course length.
- Starting course begins at the bottom of the wall so every subsequent course sheds water downward and outward over the one below.
✓Fasteners & Tape+-
- Fastener type (cap nails vs. cap staples) matches the product specified by the house wrap manufacturer for the substrate being fastened into.
- Fastener spacing (both framing O.C. and vertical spacing) matches the manufacturer's published installation instructions for the wind exposure/zone, not assumed.
- Seam tape is planned for every horizontal lap AND every vertical splice, not just the horizontal seams.
- Flashing tape is planned at every window and door opening — head, both jambs, and sill — before the next course is installed over it.
✓Installation & Final Check+-
- No housewrap was installed over wet or unacceptably out-of-tolerance sheathing — the substrate was dry and sound before wrapping.
- Every seam, splice, and flashing-taped opening was pressed/rolled firmly so the tape's adhesive fully engages, not just laid in place.
- Any tears, punctures, or fastener mis-hits were patched with matching tape before the siding/furring was installed over them.
Full QC Checklist+−
Verify measurement, roll/overlap planning, tape/fasteners, and installation before handover.
✓Measurement & Takeoff+-
- Every wall section's width and height were measured on site, not estimated from a floor plan alone.
- Window and door counts and typical sizes were recorded for each wall section that has openings, not assumed uniform across the whole house.
- Wall sections match the building's actual elevations, including any bump-outs, gables, or additions entered as their own rows.
- A triangular gable end was entered with a reasonable average height, or its area was measured separately.
- Roll size selected matches the actual product being purchased, not left at the default without checking the supplier's catalog.
- Framing spacing and fastener vertical spacing match the actual stud layout and product instructions, not just this calculator's defaults.
✓Roll & Overlap Planning+-
- Horizontal (course-to-course) lap overlap matches the specific house wrap product's own installation instructions, not assumed from this calculator's default alone.
- Vertical/end lap overlap at any splice joint is planned and communicated to the install crew — this calculator's splice and roll counts already account for it wherever a course needs splicing.
- Roll count for ordering includes this calculator's waste allowance, not the raw unadjusted course length.
- Starting course begins at the bottom of the wall so every subsequent course sheds water downward and outward over the one below.
- Each wall's own course count and seam locations were checked against the actual roll width being purchased, not assumed from a different roll size.
✓Fasteners & Tape+-
- Fastener type (cap nails vs. cap staples) matches the product specified by the house wrap manufacturer for the substrate being fastened into.
- Fastener spacing (both framing O.C. and vertical spacing) matches the manufacturer's published installation instructions for the wind exposure/zone, not assumed.
- Seam tape is planned for every horizontal lap AND every vertical splice, not just the horizontal seams.
- Flashing tape is planned at every window and door opening — head, both jambs, and sill — before the next course is installed over it.
- Flashing tape sequence follows a shingle-style order (sill first, then jambs, then head) so water sheds outward at every layer.
- Tape and fastener box/roll quantities including the waste allowance — not the raw calculated totals — were used for the material order.
✓Installation & Final Check+-
- No housewrap was installed over wet or unacceptably out-of-tolerance sheathing — the substrate was dry and sound before wrapping.
- Every seam, splice, and flashing-taped opening was pressed/rolled firmly so the tape's adhesive fully engages, not just laid in place.
- Manufacturer-specified exposure time limits (if any) for leaving the wrap exposed to UV/weather before siding installation were checked and scheduled around.
- Any tears, punctures, or fastener mis-hits were patched with matching tape before the siding/furring was installed over them.
- This calculator's planning-level estimate — not the as-built wrap — was reconciled against the actual material used, and the difference investigated if large.
- Local building code's water-resistive barrier requirement (e.g. IRC R703.2) and the product's own installation instructions were both confirmed before final sign-off.
Reference Tables
Common roll sizes
| Roll Size | Coverage | Typical Use |
|---|---|---|
| 9 ft x 100 ft (900 sq ft) | 900 sq ft | Standard residential walls |
| 9 ft x 150 ft (1,350 sq ft) | 1350 sq ft | Standard residential walls |
| 10 ft x 150 ft (1,500 sq ft) | 1500 sq ft | Taller single-story/commercial walls |
One roll size is used for the whole project — confirm your supplier's actual SKU before ordering.
Lap overlap guide
| Overlap Type | Commonly Cited Range | This Calculator's Default |
|---|---|---|
| Horizontal (course-to-course) | 2 - 12 in | 6 in |
| Vertical / End Lap (splice) | 2 - 12 in | 6 in |
Sources partially disagree — always confirm against your specific product's own installation instructions before finalizing.
Fastener spacing guide
| Spacing | Typical Use |
|---|---|
| 12 in O.C. | Tighter spacing / high-wind exposure |
| 18 in O.C. | Common mid-range default |
| 24 in O.C. | Manufacturer max, calm conditions |
Waste allowance guide
| Job Complexity | Typical Waste % |
|---|---|
| Simple rectangular walls, few openings | 5% |
| Typical residential job (default) | 10% |
| Many openings or complex cuts | 15% |
Confirm roll size, lap overlaps, fastener type/spacing, and flashing sequence against the local building code (e.g. IRC R703.2) and the specific product's installation instructions before finalizing an order — these figures are general planning guidance only.
How to Use the House Wrap Calculator
- Add one wall section per elevation with its width, height, and any window/door counts and average sizes.
- Choose the roll size you plan to buy, and confirm the horizontal and vertical/end lap overlaps against your product's install guide.
- Choose framing spacing, fastener vertical spacing, and fastener type.
- Set a waste allowance, then add optional cost inputs for a full material + labor estimate.
Practical House Wrap Tips
- Start the first course at the bottom of the wall so every course above sheds water outward and downward over the one below it — never start at the top.
- Flash openings in a shingle-style sequence: sill first, then jambs, then head — so each layer sheds onto the one below, never the reverse.
- Press or roll every seam and flashing tape joint firmly — adhesive that is only laid in place, not pressed, is a common cause of early tape failure.
- Check your specific product's UV/weather exposure time limit before siding goes on — some house wraps degrade if left exposed too long.
- Patch any tear, puncture, or mis-driven fastener hole with matching tape immediately — small gaps are easy to miss once siding covers them.
- Order 5-10% extra beyond this calculator's waste-adjusted total on a complex, many-opening job — cutting around numerous openings generates more offcuts than a plain wall.
Common Mistakes
- Starting the first course at the top of the wall instead of the bottom, so water is shed INTO the seam below rather than over it.
- Flashing openings in the wrong sequence (head before sill/jambs), trapping water instead of shedding it outward.
- Assuming deducting window/door area from Net Wrap Area also reduces the roll count — it does not, since rolls must span the full gross wall regardless of openings.
- Using a flat area-over-coverage ratio to estimate rolls instead of accounting for real course overlap, which understates how much material multi-course tall walls actually need.
- Skipping seam tape at vertical splices because only the horizontal laps were budgeted for.
- Leaving house wrap exposed to UV and weather far longer than the product's rated limit before siding is installed.
House Wrap Calculator Limitations
- This calculator provides estimation only and does not replace a manufacturer's installation guide, IRC R703.2, or a site-specific survey.
- Window and door area is fully deducted from the reported Net Wrap Area, but roll quantities are always computed from each wall's full GROSS width and height — deducting openings never reduces the roll count, since house wrap must be bought and installed as a continuous roll spanning the entire wall.
- The Vertical/End Lap input is consumed as real overlap material wherever a course actually needs splicing (its length exceeds one roll) — it has no effect on a wall that fits on a single continuous roll, since no splice occurs there at all.
- This calculator uses a single project-wide roll size/SKU. A job genuinely mixing two different roll sizes is not modeled.
- There is no discrete corner accessory, unlike this category's Stucco (corner bead) or Fiber Cement/Wood Siding (corner boards) calculators — house wrap simply continues or overlaps at a corner.
- Each wall section is modeled independently. A continuous wrap-around-corner sequence that might reduce real-world seam count across adjoining walls is not modeled — a disclosed, conservative simplification.
- Fasteners are counted from this wall's own gross width/height grid, ignoring exact opening cutouts — a disclosed planning approximation, not a substitute for an actual framing layout.
- This calculator does not include a rainscreen/furring-strip drainage-gap system — a different material system entirely, scoped out the same way Stucco scopes out synthetic EIFS.
- Each wall section is modeled as a rectangle. A triangular gable end should be entered with an average height approximation, or measured separately.
- Roll, seam tape, and flashing tape stock sizes are disclosed assumptions (9/10 ft wide rolls, 165 ft seam tape, 75 ft flashing tape) — confirm your actual supplier SKU before ordering.
- This calculator estimates material quantity and cost only, not structural wall design or moisture management/building-envelope performance.
- Final roll size, lap overlaps, fastener spacing, and flashing sequence should follow the local building code and the specific product's own installation instructions.
Related Construction Calculators
You may also find these calculators useful for the same job:
- Stucco Calculator
Compare against a plaster-system estimate for the same walls.
- Fiber Cement Lap Siding Calculator
Compare against a board-based siding estimate for the same walls.
- Wood & Engineered Wood Siding Calculator
Compare against a natural or engineered wood siding estimate.
- Vapor Barrier Calculator
Estimate a separate interior vapor retarder for the same building.
Disclaimer: This calculator provides approximate results for planning and estimation purposes only. Actual requirements may vary based on site conditions, materials, workmanship, and local building regulations. Always consult a qualified engineer, architect, or construction professional before making final decisions.