Is house wrap required by code?

Yes. IRC R703.1.1 requires a weather-resistant barrier behind exterior cladding. House wrap is the most common way to meet this requirement.

Tyvek has higher vapor permeability. Typar has better UV resistance and tear strength. Both are excellent products meeting code requirements.

Does house wrap go over or under rigid foam?

It depends on the assembly. House wrap typically goes directly over sheathing, then rigid foam over it. Some assemblies use the rigid foam with taped seams as the WRB.

House WrapGenerating image…

Insulation

Air Barrier

$0.15-$0.40 per sq ft

House Wrap: Weather-Resistant Barrier for Walls (2026)

Prepared by Lumberama's Building Materials Team

|Last updated May 15, 2026|Sources & methodology

House wrap is a synthetic weather-resistant barrier (WRB) installed over exterior wall sheathing and behind siding to block wind and water while allowing moisture vapor to escape from inside the wall assembly. It is a critical component of modern wall construction that prevents water infiltration and energy loss.

Key Features

Blocks wind and liquid water; Allows vapor to escape; Reduces air infiltration; Installed over sheathing; Behind all siding types

Specifications

Width: 3

or 9 ft rolls. Length: 100-200 ft. Permeance: 10-60 perms (vapor-permeable). Water resistance: meets ASTM E331. Air resistance: meets ASTM E2178.

Applications

Residential exterior walls; Commercial wall assemblies; Behind all siding types; Over sheathing; Weather protection during construction

Installation Overview

Wrap house starting from bottom, overlapping courses shingle-style minimum 6 inches horizontally and 12 inches vertically. Staple or cap-nail to sheathing. Tape all seams and around penetrations. Integrate with window and door flashing.

Pros & Cons

Pros

✓ Prevents water infiltration; Allows wall drying; Reduces air leakage; Easy to install; Required by code

Cons

✗ Must be properly lapped and taped; Can be torn by wind before siding; Surfactant wash-off with some sidings; UV exposure limited; Must integrate with flashing

Top Brands

DuPont Tyvek

Typar

CertainTeed

Owens Corning

Code Requirements

Weather-resistant barrier required per IRC R703.1.1. Must be installed shingle-style. Must integrate with window and door flashing per IRC R703.4. Air barrier per IRC N1102.4.

Buying Tips

DuPont Tyvek is the industry standard but all major brands meet code. Buy matching tape for seams - generic tape may not adhere properly. Budget for cap nails or staples and seam tape.