Description
What it is — and when 9″ is the right width
DuPont Flashing Tape is a self-adhered flashing made with a 100% butyl adhesive layer, engineered to seal the joint between the rough opening and the water-resistive barrier. No asphalt, no modified bitumen — pure butyl on a polypropylene film, with a heavy-duty split release liner so you can set it in two passes without wrinkles.
The width decides the job:
- 4″ — sheathing seams, narrow jambs, trim details
- 6″ — standard window jambs and heads
- 9″ — window sills and mid-size openings. The width most crews reach for on sill pans, where the lap has to run up the jamb and out onto the sheathing
- 12″ — wide sills, door pan flashing, large openings
If you are flashing standard residential windows, 9″ on the sill and 6″ on the jambs and head is the combination that covers most of a house.
Specifications
| Adhesive | 100% butyl (no asphalt or modified bitumen) |
| Backing | Polypropylene film |
| Release liner | Heavy-duty siliconized paper, split design |
| Size | 9 in × 75 ft (1 roll) |
| Application temperature | Down to 25°F (-4°C) |
| UV exposure | Up to 120 days |
| Primer | Not required on most common building materials |
| Factory carton | 4 rolls |
| Condition | New, factory sealed |
Standards and warranty
| AAMA 711 | Class A, Level 3 — highest classification |
| ASTM E1677 | Assembly air leakage < 0.04 cfm/ft² |
| ASTM E331 | No water leakage at 300 Pa (6.24 psf) |
| ASTM E96 | Water vapor permeability < 1 perm |
Backed by DuPont 10-Year Limited Warranties when installed as part of the Tyvek® WRB system.
Installation notes
You need:
- A clean, dry, frost-free surface
- Rough sill framing level or sloped slightly to the exterior
- A chemically compatible primer over concrete, masonry, and glass-mat exterior gypsum sheathing
Do not use it for:
- Through-wall flashing applications
- Installing over cap fasteners
How many rolls you need
75 ft per roll. Quick math:
- Sill pans on standard 3 ft windows (about 5 ft per sill with laps): roughly 15 sills per roll
- Full perimeter of a 3 ft × 5 ft window (about 16 ft with laps): roughly 4 windows per roll
For a typical single-family house with 12 to 15 openings, one roll of 9″ covers the sills with room to spare. Most crews pair it with 6″ for the jambs and heads.
Same roll, lower price: clearance stock
We keep a few rolls whose packaging took a beating in storage. The tape inside is factory-sealed and carries the same DuPont 10-year limited warranty as a new roll — only the carton looks rough.
- DuPont Flashing Tape 9″ × 75 ft — clearance — $54.99 instead of $66.99, while stock lasts
Contractor and volume pricing
The factory carton is 4 rolls. Call (832) 463-7946 or email sales@85builders.com with your quantity and the job-site ZIP code and we will send carton pricing the same business day.
We accept Texas resale certificates for tax-exempt purchases.
Frequently asked questions
Is this genuine DuPont?
Yes. New, factory-sealed product in original DuPont packaging. Not generic, not repackaged.
Do I need a primer?
On most common building materials, no. You do need one over concrete, masonry, and glass-mat exterior gypsum sheathing — use a chemically compatible primer.
Can I install it in cold weather?
Down to 25°F (-4°C). Below that the butyl will not bond reliably and you will get failures.
How long can it stay exposed before the wall is closed in?
120 days of UV exposure. If the schedule runs longer than that, it needs to be covered.
Can I use it for through-wall flashing?
No. DuPont specifically excludes that application.
How fast does it ship?
We ship next business day from Cypress, TX.
Also Available
Need a wider roll? See DuPont Flashing Tape 12″ x 75′ for sill pans, wide headers, and commercial window openings.
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