Description
What it is — and when 4″ 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, pipe and wire penetrations, trim transitions. The width for everything that is not a full window opening
- 6″ — standard window jambs and heads
- 9″ — window sills and mid-size openings
- 12″ — wide sills, door pan flashing, large openings
Most crews keep a roll of 4″ on the truck permanently. It is the one you reach for when something on the wall needs sealing and it is not a window.
Specifications
| Adhesive | 100% butyl (no asphalt or modified bitumen) |
| Backing | Polypropylene film |
| Release liner | Heavy-duty siliconized paper, split design |
| Size | 4 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
- Seams lapped shingle-style so water sheds outward
- 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:
- Vertical sheathing seams on 8 ft walls: roughly 9 seams per roll
- Pipe and wire penetrations (about 2 ft each): roughly 35 penetrations per roll
One roll goes a long way on details. Order it alongside your 6″ and 9″ so the crew is not improvising with the wrong width.
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.
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