What width flashing tape for windows?

4" for sill and sides, 6-9" for the head flashing. Wider tape provides better coverage and is easier to install.

Does it go over or under house wrap?

Sill tape goes under house wrap, side and head tape typically goes over house wrap to properly shingle-lap water away.

Flashing TapeGenerating image…

Adhesives & Sealants

Tapes

Budget: $10-$20 (4" x 75 ft basic) | Mid-range: $20-$40 (6" x 75 ft quality brand) | Premium: $40-$80 (9-12" premium or UV-resistant)

Flashing Tape: Self-Adhesive Waterproofing Tape for Windows & Doors (2026)

Prepared by Lumberama's Building Materials Team

|Last updated May 25, 2026|Sources & methodology

Flashing tape is a self-adhesive waterproofing membrane used around windows, doors, and building penetrations to prevent water intrusion. Made from rubberized asphalt, butyl rubber, or acrylic adhesive with a flexible backing, it creates a continuous water barrier at vulnerable transition points in the building envelope.

Key Features

Self-adhesive peel-and-stick application; Rubberized asphalt or acrylic adhesive; Multiple widths from 4" to 12"; UV resistant options for exposed applications; Conforms to irregular surfaces

Specifications

Types: rubberized asphalt

butyl

acrylic | Widths: 4"

12" | Lengths: 33 ft

75 ft rolls | Temperature: apply above 25°F | Adhesion: wood

OSB

concrete

vinyl | UV exposure: varies (check product)

Applications

Window rough opening flashing; Door frame waterproofing; Deck ledger board flashing; Roof penetration sealing; Sill pan creation for windows

Installation Overview

Clean and dry surfaces. Cut tape to length with scissors or knife. Peel backing and apply to sill first, then sides, then head (shingle-lap from bottom up). Press firmly with J-roller for full adhesion. Overlap seams by 2 inches minimum.

Pros & Cons

Pros

✓ Excellent waterproofing at critical transitions; Easy peel-and-stick application; Conforms to irregular surfaces; Critical for window and door protection

Cons

✗ Difficult to reposition once applied; Some types not UV resistant; Must apply above minimum temperature; Primer may be needed on some substrates

Top Brands

Grace Vycor

Protecto Wrap

ZIP System

Code Requirements

IRC R703.8 requires window and door flashing. Must be installed per window manufacturer instructions for warranty. Must be compatible with water-resistive barrier (WRB).

Buying Tips

Use quality brand tape for windows - failures here cause major water damage; Apply in the correct sequence: sill, sides, then head (bottom to top shingle pattern); Press firmly with a J-roller to ensure full adhesion