What is house wrap?

What this means for your home project

1. Read the wrap manufacturer’s corner-lap instructions and record the overlap specified for the proposed product. Source: Building America Solution Center, read 2026-11-05.
2. Before the siding goes on, look at the seam tape for areas that have not bonded to the wrap. Source: Building America Solution Center, read 2026-11-05.
3. Request a written full-retrofit scope stating cladding removal, sheathing assessment and any sheathing replacement needed before the new membrane. Source: Building America Solution Center, read 2026-11-05.
4. Request the wrap manufacturer’s compatible-sealant recommendations so the proposed sealant can be compared with that list. Source: Building America Solution Center, read 2026-11-05.

How much should house wrap overlap?

Use the Solution Center’s corner and seam guidance to read the product’s lap instructions before siding covers the work (read 2026-11-05). “Begin at a building corner, leaving a 6- to 16-inch overlap to wrap around the corner.” (source) “The amount of overlap will vary according to the product manufacturer’s recommendations.” (source) “Stagger the ends of each course so seams between courses do not align and overlap all seams following manufacturer recommendations.” (source)

Is house wrap a vapor barrier?

The Solution Center describes two plastic-wrap constructions; use their drying behavior to distinguish water shedding from vapor control (read 2026-11-05). “Perforated products have tiny holes punched in them.” (source) “The holes allow water vapor to pass through the material but are small enough to block droplets of liquid water, which are held together by surface tension and too large to pass through the holes.” (source) “Non-perforated products rely on tiny interstitial gaps between fibers or woven bands of plastic that allow water vapor to diffuse through the material.” (source)

Which is better, felt paper or house wrap?

Compare materials using the Solution Center’s test guidance and historical 2018 IRC R703.1.1 summary, rather than assuming either label settles suitability (read 2026-11-05). “Compared with house wraps, all building papers tend to tear more easily during installation.” (source) “To evaluate the differences, look for the performance results of ASTM tests for water holdout and permeability (DOE 2000).” (source) “2018 IRC R703.1.1 states that the exterior envelope shall be designed and constructed in a manner that prevents the accumulation of water within the wall assembly by providing a water-resistant barrier behind the exterior cladding as required by Section R703.2 and a means of draining to the exterior any water that penetrates the exterior cladding.” (source)

Do I need to replace the WRB when I replace siding?

For contractor-led replacement, the Solution Center’s existing-wall guidance distinguishes the condition assessment from repairs needed beneath the wrap (read 2026-11-05). “Remove a portion of the cladding at the base of the wall and examine the condition of the exposed building wrap, felt paper, or water control membrane, as well as the sheathing beneath it.” (source) “Damp sheathing will dry with improved drainage, but rotting sheathing should be removed and replaced.” (source)

Can taped house wrap be the air barrier?

Use the Department of Energy’s conditions to clarify whether your written scope includes air control as well as water management (read 2026-11-05). “To serve as an air barrier, the housewrap must be sealed at the joints using special tape.” (source) “Housewrap may serve as a continuous air barrier, but only if all conditions are met.” (source) “It must be integrated with flashing materials in order to perform.” (source)

What drives the cost of WRB work?

The Solution Center’s full-retrofit scope identifies removal and underlying wall repairs as work to resolve when comparing installation proposals (read 2026-11-05). “To retrofit an existing house with a new drainage plane, the existing cladding and building paper should be removed in their entirety, the condition of the existing exterior sheathing should be assessed, and the sheathing should be replaced if necessary before installing a new water control membrane per the guidelines in the “Description” tab.” (source)

Sources

• Drainage Plane Behind Exterior Wall Cladding — Building America Solution Center; read 2026-11-05.
• Flashing at Bottom of Exterior Walls — Building America Solution Center; read 2026-11-05.
• Continuous Air Barrier in Exterior Walls: Housewrap — U.S. Department of Energy; read 2026-11-05.
• Drainage Plane Behind Exterior Wall Cladding — materials comparison — Building America Solution Center; read 2026-11-05.