How Much House Wrap Do I Need? Rolls by House Size
House wrap is the water-resistive barrier under the siding. A house with a 140 ft perimeter, 9 ft walls and two gables has 1,484 sq ft of wall, and needs 2 rolls of 9 × 100 ft wrap once the laps and 10% waste are added: 1,728 sq ft in all. The house wrap calculator gives the rolls for your house.
Rolls by house size
With 9 ft walls, two gables 8 ft high, 6 in laps and 10% waste:
| Footprint | Perimeter | Wall area | 9 × 100 ft rolls | 9 × 150 ft rolls | 10 × 100 ft rolls |
|---|---|---|---|---|---|
| 24 × 30 ft | 108 ft | 1,164 ft² | 2 | 2 | 2 |
| 28 × 40 ft | 136 ft | 1,448 ft² | 2 | 2 | 2 |
| 30 × 50 ft | 160 ft | 1,680 ft² | 3 | 2 | 2 |
| 40 × 60 ft | 200 ft | 2,120 ft² | 3 | 2 | 3 |
Why the laps matter
Each course overlaps the one below it, so the wrap you buy is more than the wall you cover. With a 9 ft roll and a 6 in lap the overlap uses about 6% extra. For the default house:
| Lap | Area to buy | Rolls of 9 × 100 ft |
|---|---|---|
| 2 in | 1,663 ft² | 2 |
| 4 in | 1,695 ft² | 2 |
| 6 in | 1,728 ft² | 2 |
Choosing a roll
- A 9 ft roll fits a standard 8 ft wall plus the rim joist, so it gives one course a story.
- A 10 ft roll suits taller walls and fewer joints.
- The 150 ft rolls cost less per square foot but are heavy and awkward to hang alone.
- Read the label: roll sizes and the lap they ask for vary by make.
Hanging it
- Start at the bottom and work up, with each course over the one below it, so water runs down the face of the wrap.
- Take the wrap about a foot past each corner, so there is no joint at the corner.
- Wrap over the windows and doors, then cut an I and fold the flaps into the opening, and flash it as the window maker says.
- Tape the seams if the maker asks, and fasten with cap nails or cap staples.
- Cover it with siding soon: most wraps are rated for a few months of sun.
See the siding calculator and the siding project materials calculator for the cladding. Roll sizes and lap rules differ by product, so follow the instructions on the roll.
Frequently asked questions
How many rolls of house wrap do I need?
Add the walls and gables, add about 6% for the laps and 10% for waste, and divide by the roll area. 1,484 ft² of wall takes 2 rolls of 9 × 100 ft or 2 of 9 × 150 ft.
What size are rolls of house wrap?
Common rolls are 9 × 100 ft (900 ft²), 9 × 150 ft (1,350 ft²), 10 × 100 ft and 10 × 150 ft.
How much should house wrap overlap?
The IRC asks for 2 inches at horizontal joints and 6 inches at vertical joints. Many makers say 6 inches throughout, with the seams taped.
Do I subtract windows and doors?
No. The wrap goes over the openings and is cut and folded in, so use the full wall area.
Should I hang it horizontally?
Most makers say yes, starting at the bottom, so each joint sheds water onto the course below.
More guides
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.
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