BuildMeter guide · Structures & Carpentry
House Wrap Seams and Tape Planning Guide
Plan horizontal laps, roll-end joints, opening perimeters and penetration tape while keeping the wall drainage plane continuous and shingle-lapped.
Direct answer
What to know first
Estimate tape from every seam that the selected house-wrap system requires: horizontal course laps, vertical roll-end joints, window and door flashing interfaces, penetrations and repairs. Product approval, substrate preparation and correct lapping matter more than simply applying more tape.
Open House Wrap Seam Tape CalculatorCount the seams the selected wall system actually requires
House-wrap tape is not estimated from wall area alone. The useful takeoff is the total length of horizontal laps, vertical roll-end joints, opening interfaces, penetrations and repairs that the manufacturer requires to be taped. If the wrap is installed in horizontal courses, the effective course width is the roll width minus the required lap.
| Component | How to measure it | Why it matters |
|---|---|---|
| Horizontal course seams | Building perimeter × seams between courses | Connects stacked courses while preserving drainage direction |
| Vertical roll-end seams | Number of roll changes × course width | Closes joints created when one roll ends |
| Openings | Measured jamb, head and sill interfaces | Coordinates wrap with sill pans and flashing tape |
| Penetrations | Measured or typical tape per pipe, vent or fixture | Maintains continuity around interruptions |
Worked example
A 180 ft perimeter building has 9 ft walls and uses 9 ft house wrap with a 6 in. lap. One course covers the wall height, so there is no horizontal course seam. If the average uninterrupted run is 75 ft, three roll sections are needed around the perimeter, creating two vertical joints. At 9 ft each, that is 18 ft of vertical seam. Add 260 ft around openings and 54 ft for 18 penetrations at 3 ft each. The base is 332 ft; with 12% allowance the order is about 372 ft, or three 165 ft rolls.
Tape must work with the drainage plane
More tape does not correct reverse laps or poorly integrated flashing. Water-resistive barriers should be layered so upper materials drain over lower materials. Window and door details need a sill drainage path, jamb flashing and a head detail that connects back to the wall water-control layer.
Common mistakes
- Counting wall area but not roll-end joints.
- Using a tape not approved for the wrap or substrate.
- Taping over dusty, wet, cold or contaminated surfaces outside product limits.
- Sealing the bottom of a detail that is intended to drain.
- Assuming window perimeter alone includes sill-pan corner patches and head-flashing extensions.
Sources and professional limits
- U.S. DOE Building Science Education — drainage plane behind exterior cladding
- Building Science Corporation — taped sheathing drainage-plane guidance
- Building Science Corporation — common flashing details
This guide estimates tape quantity only. The wall assembly, climate, product approval, exposure and opening details control the actual installation.