DuPont Tyvek Building Wrap 9' x 150'

DuPont Tyvek Building Wrap 9’ x 150’ delivers 1,350 square feet of coverage with 56 perm vapor permeability and air resistance less than 0.004 cfm/ft² at 1.57 psf. The wrap blocks wind-driven rain while letting interior moisture escape — solving the moisture trap problem that cheaper alternatives can’t touch.

Montana’s freeze-thaw cycles demand this balance. The 56 perm rating (ASTM E2556 Type II) means trapped moisture from temperature swings won’t rot sheathing or create mold factories inside walls. At 16.875 pounds per roll, crews haul manageable loads up scaffolding compared to heavier barrier systems.

Performance That Matters in Mountain Country

The numbers that separate Tyvek from budget wraps:

Specification	Value	Testing Standard
Vapor Permeability	56 perm (Method A), 54 perm (Method B)	ASTM E2556 Type II
Air Resistance	< 0.004 cfm/ft² @ 1.57 psf	ASTM E2178, ASTM E1677 Type I
Water Resistance	250 cm hydrostatic pressure	AATCC 127
Drainage Efficiency	> 90%	ASTM E2273
UV Exposure Rating	Up to 120 days (approx. 4 months)	Manufacturer spec
Tensile Strength	30 lb/in	ASTM D882
Fire Rating	Class A; Flame Spread: 0, Smoke: 10	ASTM E84
Max Temperature	180°F	Manufacturer spec

That Class A fire rating (0 flame spread, 10 smoke developed) meets Montana’s wildfire interface requirements. The 120-day UV resistance covers typical construction delays through a Montana summer — critical when material sits exposed at 4,000+ feet elevation where UV intensity runs 20% higher than sea level.

The high-density polyethylene (HDPE) non-woven, non-perforated fiber construction creates a unique barrier. Unlike perforated wraps that rely on tiny holes, Tyvek’s fiber structure manages moisture at the molecular level. Water beads can’t penetrate, but vapor molecules pass through.

Installation Reality Check

The translucent surface lets installers see studs and sheathing through the wrap — speeds up fastener placement and reduces missed studs. Installation requires 6-inch overlaps at seams, sealed with Tyvek Tape, with proper flashing integration at all penetrations.

The wrap works on OSB, plywood, and gypsum board substrates. The material clings to walls for easier positioning and quieter installation — less flapping in Montana’s afternoon winds.

Coverage math: Each 9’ x 150’ roll covers 1,350 square feet. A typical 2,000-square-foot ranch needs two rolls minimum, plus 10% for overlaps and waste. Three rolls handles most single-story homes with proper overlap.

The Contractor Verdict

Users praise its superior breathability, which helps prevent mold and moisture buildup, while effectively sealing out air and water infiltration. With ratings of 4.6-4.7 out of 5 stars across 200+ reviews at major retailers, it’s the industry standard for housewraps.

DuPont backs the product with a 10-year limited warranty when installed per their guidelines. That matters when callbacks eat profit margins.

The downsides exist. Some contractors note that Tyvek can be more expensive than other wraps, and proper installation is crucial to maximize its benefits. Budget wraps cost half as much. They also trap twice as much moisture.

Typar often features longer UV exposure ratings (6 months vs 120 days) — relevant for projects with extended exposure times. But Typar’s thinner profile means less durability under jobsite abuse.

Worth it for contractors building quality homes in Montana’s climate. The vapor permeability alone justifies the premium on any job where moisture management matters. Add the Class A fire rating for WUI zones and proven drainage efficiency — Tyvek earns its market position.

Not perfect. But for builders who understand that what goes under the siding matters as much as what goes on top, Tyvek delivers measurable advantages over bargain alternatives.

Frequently Asked Questions

Q: How much area does one roll actually cover?

Each 9’ x 150’ roll provides 1,350 square feet of coverage. Factor in required 6-inch overlaps and 10% waste — plan on 1,200 effective square feet per roll for accurate ordering.

Q: What’s the real UV exposure limit in Montana?

Tyvek handles up to 120 days (approximately 4 months) of UV exposure. At Montana elevations with intense summer sun, don’t push this limit. Schedule siding installation within 90 days to maintain warranty coverage.

Q: Does Tyvek work with all sheathing types?

Yes — compatible with OSB, plywood, and gypsum board substrates. Use polyurethane or acrylic sealants, and stick with DuPont-branded tapes and flashings for system compatibility.

Q: How does the fire rating help in wildfire zones?

Tyvek carries a Class A fire rating with 0 flame spread and 10 smoke developed (ASTM E84). This meets Montana’s wildfire interface building requirements and helps qualify structures for better insurance rates in high-risk areas.

Q: What’s included with each roll?

One roll of DuPont Tyvek HomeWrap (9 ft x 150 ft). Tyvek Tape, flashings, and fasteners sold separately. Budget for these accessories — proper installation requires all components.