In standard exterior wall construction, Tyvek (house wrap) goes on before your exterior rigid foam insulation. It is installed directly over the wood sheathing to serve as your primary water and air barrier.
In new construction, or in remodeling projects in which the existing windows will be replaced, the DuPont™ Tyvek® WRB can be installed under or over the DuPont Exterior Continuous Insulation based on whether the windows will be aligned with the exterior finished wall or recessed from it.
Yes, House Wrap Does Come First!
Often, those installing foam insulation ask, “Do I put house wrap on first or second?” Whether you're installing James Hardie siding or not, house wrap is always applied first. The experts place the material in the proper orientation to achieve maximum insulation.
As a general rule, house wrap should be installed before the windows. This ensures a "shingled" effect, allowing water running down the wall to flow over the window flashing rather than getting trapped behind the wrap.
Installing Housewrap With Rigid Foam Insulation
Homeowners often ask if house wrap can be installed with foam insulation. The answer is yes. Combining these two products makes your home more insulated against wind and weather. When installing house wrap with rigid foam, it should typically go under the insulation.
Housewrap is installed between the sheathing and the exterior siding, and is used behind vinyl, wood clapboards, shingles or shakes, brick, and other building materials.
While Tyvek is a popular house wrap for preventing bulk water and air infiltration, it has notable disadvantages. Its effectiveness depends heavily on proper installation.
Stapling is the most common method of attaching Tyvek. Staples should be spaced 6 inches apart and driven into the studs or joists. Nailing is another option for attaching Tyvek. Nails should be spaced 12 inches apart and driven into the studs or joists.
Your window tape on the top of the window is over top of the tyvek. It should be under the tyvek on top then the tyvek lapped back over top of it. Your sides are installed correctly with you tape over top of the tyvek. I find it useful to assume every functioning exterior system should function like shingles.
Mice are curious and always searching for safe, snug, and warm nesting sites. Attics filled with blown-in insulation provide an excellent option–from the mice's point of view. As long as there is a ready food source. Mice are omnivorous and will eat and chew on almost anything including wood and electrical wires.
Because spray foam can trap moisture, hide the condition of the roof, make it difficult for surveyors to inspect, which means risks like timber decay, dry rot, and not forgetting increased fire risk. If you've got it or you're buying a property that does, this is something you need to know upfront.
In most cases, you should not tape the bottom edge of your house wrap to the foundation or flashing. The bottom edge must be left open so that any moisture trapped behind the wrap can easily drain out and escape.
No, DuPont™ Tyvek® is not a vapor barrier. It is made with unique material science to keep air and bulk water out while allowing moisture vapor inside walls to escape.
The vapor barrier always goes on the warm side of the insulation (closest to the conditioned interior of your home during the coldest months). This prevents warm, moist indoor air from reaching the colder insulation and condensing, which causes mold and rot.
No, it does not matter if Tyvek building wrap is installed upside down or even with the logos facing inward. The material is non-directional and functions exactly the same way regardless of orientation, providing the same air infiltration and moisture protection.
Yes, taping Tyvek seams is highly recommended for maximum weather protection. While it is technically optional (the manufacturer only explicitly requires tape for repairing holes or tears, and to secure overlaps to achieve an optimal air barrier), taping all vertical and horizontal seams ensures a continuous protective barrier against air and moisture infiltration.
T50 staples are the world's best-selling heavy duty staple platform. Made to deliver exceptional holding power, these staples are used for all heavy duty stapling applications from installing insulation, house wraps and roofing underlayments to upholstering fine furniture and window treatments.
The ZIP System and Tyvek both act as weather-resistive barriers (WRBs), but they work very differently. ZIP replaces standard sheathing and housewrap with an all-in-one coated board and taped seams. Tyvek is a breathable housewrap layered over standard oriented strand board (OSB) or plywood.
While Tyvek manages moisture, it's not immune to all moisture-related problems. Two of its main issues are mold growth and sensitivity to surfactants.
"Better" than Tyvek depends on your project. For home building, Zip System Sheathing and Henry Blueskin outperform traditional house wraps by acting as fully adhered, all-in-one moisture and air barriers. For camping, Polycryo is significantly lighter, more puncture-resistant, and packs smaller than Tyvek.
The healthiest, non-toxic insulation for your home is natural sheep's wool or hemp insulation. These materials contain no chemical binders or formaldehyde, actively regulate indoor humidity to prevent mold, and do not off-gas.
You do not always have to put Tyvek (house wrap) over insulation board, but when using exterior foam, it can be installed either under or over the board. The preferred method depends on your wall's moisture management design and window placement.
Yes, mold can absolutely grow under a vapor barrier. While vapor barriers are designed to block moisture, any moisture that gets trapped beneath the barrier—due to a plumbing leak, groundwater seepage, or poor installation—will create a prime environment for mold to grow, out of sight.
Yes, mice can easily get in under siding. Because their skeletal structure is incredibly flexible, they only need a gap about the size of a dime (or roughly 14one-fourth14 inch) to squeeze through. The hollow spaces behind siding act as highways, allowing them to climb and access your attic or walls.