Is housewrap required by code?

Yes. The IRC requires a water-resistive barrier (WRB) on all exterior walls behind siding. Housewrap (Tyvek, etc.), asphalt-impregnated building paper, or self-adhered membranes all satisfy this requirement. The WRB is your primary defense against wind-driven rain penetrating the wall cavity.

Can I use felt paper instead of housewrap?

Yes, #15 asphalt-impregnated building paper (tar paper) is still code-compliant as a WRB. However, synthetic housewraps outperform felt in most metrics: they are lighter, stronger, more vapor-permeable, and can withstand longer UV exposure. Felt remains popular in stucco and stone veneer applications where two layers are traditionally specified.

How many rolls of housewrap do I need?

Divide your total exterior wall area (perimeter times wall height) by the roll coverage (typically 1,000 sq ft for standard Tyvek rolls). Add 15% for horizontal and vertical overlaps, window and door wrapping, and waste. A 2,000 sq ft wall area typically requires 2 to 3 rolls.

What tape should I use for housewrap seams?

Always use tape recommended by the housewrap manufacturer — Tyvek tape for Tyvek, for example. Contractor sheathing tape (Zip, 3M 8067, or similar) also works on most WRB products. Do not use duct tape, masking tape, or standard packing tape, as these will fail quickly and compromise the air and water barrier.

Does housewrap go over or under window flashing?

The housewrap is cut at window and door openings in a specific sequence. The sill flashing goes over the housewrap at the bottom, the jamb flashing overlaps the sill flashing, and the head flap of the housewrap laps over the top flashing to create a shingle-lap water management system. Incorrect sequencing is the number one cause of window leaks.

How long can housewrap be left exposed before siding?

Most housewrap products, including Tyvek HomeWrap, can be left exposed for up to 120 days (4 months) before UV degradation reduces performance. Some premium products offer 6 to 12 month UV exposure ratings. Plan to install siding within the manufacturer's specified timeframe to maintain warranty coverage.

Breather Membrane Calculator

How many rolls of breather membrane do I need? Free calculator by wall area — covers standard roll widths with overlap.

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Enter Your Measurements

How to Use This Calculator

1Calculate total exterior wall area (perimeter × height).
2Enter roll coverage (standard Tyvek HomeWrap = 1000 sq ft/roll).
3Click Calculate.

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About This Material

Housewrap is a synthetic weather-resistant barrier (WRB) installed over wall sheathing and behind siding to protect the building from bulk water infiltration while allowing water vapor to escape from inside the wall cavity. DuPont Tyvek HomeWrap is the most widely recognized brand, but other options include Tyvek DrainWrap (with built-in drainage channels), Henry Blueskin VP100 (self-adhered), and ZIP System sheathing tape (integrated WRB). Standard housewrap comes in 9-foot by 100-foot or 150-foot rolls covering 900 to 1,500 sq ft per roll, priced at $100 to $200 per roll. The key performance metrics are water holdout (resistance to liquid water penetration) and vapor permeance (ability to let moisture vapor pass through). All seams, penetrations, and window/door openings must be sealed with manufacturer-compatible tape. Housewrap must not be left exposed to UV for more than 90 to 120 days, as sunlight degrades its performance.

Next Steps:

Vinyl Siding Calculator →Hardie Plank Siding Calculator →Window Flashing Calculator →

Installation Tips

•Start at the bottom, working upward. Overlap horizontal seams 6" minimum.
•Tape all seams, penetrations, and window openings with compatible flashing tape.
•Install windows and doors before cutting holes in housewrap.

Common Mistakes to Avoid

Not taping seams — most air infiltration occurs at seams and penetrations.
Installing upside down — Tyvek is directional.
Leaving housewrap exposed to UV for more than 90 days (degrades performance).

Breather Membrane Calculator

How to Use This Calculator

About This Material

Installation Tips

Common Mistakes to Avoid

Frequently Asked Questions

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