Description
The roof roll
Twelve inches is the width Huber points at roof valleys — it seals a valley in a single continuous piece, six inches onto each plane, with no lap running down the one line on the roof where water is guaranteed to concentrate.
That is the whole argument. A valley taped out of narrower strips has a seam somewhere in the trough. This width lets you run the valley in one pass from ridge to eave on most residential runs, and the only joints are where you deliberately lap two rolls end to end, well up the slope.
Read this before you buy it for a roof
ZIP System flashing tape is not a substitute for a self-adhering ice and water barrier. Huber states that plainly, and it matters most in exactly the application this width is sold for. In a climate that requires ice barrier at the eaves and valleys, this tape does not replace it — it seals the panel seams and the valley as part of the ZIP System roof assembly, and the ice barrier is a separate, additional product where code calls for one.
Get that straight with your inspector before the roof goes on, not after.
Type III construction
ZIP System flashing tape is recognized for Type V construction generally, and additionally for Type III construction when taping ZIP System sheathing panel seams in roof applications. If you are working commercial or multifamily under Type III, that carve-out is specifically about roof panel seams — which is where a 12-inch roll usually ends up.
Specifications
| Type | Pressure-sensitive flashing tape, linered |
| Thickness | 12 mils (0.012 in) |
| Adhesive | Acrylic — requires rolling to activate |
| Size | 12 in × 50 ft (1 roll) |
| Installation temperature | 0°F – 120°F |
| Exposure limit | 180 days, then cover with a code-compliant roof or wall covering |
| Substrates | OSB, wood, steel, aluminum, vinyl, PVC, ZIP System sheathing |
| Huber part number | S-20025 |
| UPC | 728265020259 |
| Shelf life | 24 months from manufacture, stored below 90°F |
| Condition | New, factory sealed |
Code and warranty
| Performance standard | AAMA 711 and AC148 compliant |
| Code acceptance | IRC and IBC recognized under ICC-ES ESR-2227 |
| Construction type | Type V; Type III for taping ZIP System panel seams in roof applications |
| Warranty | 30-year system warranty when used with ZIP System sheathing panels |
How far 50 feet goes
Valley length runs with the rafter, not the plan dimension — a valley on a simple gable-to-gable intersection is longer than the footprint suggests. Rough planning numbers:
- A 14 ft valley: about 3 valleys per roll
- A 20 ft valley: 2 valleys per roll, with 10 ft left
- A 24 ft valley on a larger plan: one roll does two, one full run and most of the second
Measure the actual valley before you order. A cross-gable plan with two valleys is one roll; a hip-and-valley roof with four or five is two, and you want the second roll on site rather than a lap you did not plan.
The rest of the roof
Panel seams on the deck are a narrower job — the 6-inch roll or the 3.75-inch handle those at a much lower cost per foot. Save the 12-inch for the valleys and the wide transitions that actually need it.
For pipe penetrations, curved details and anything that has to conform rather than lie flat, flashing tape is the wrong tool entirely — that is what ZIP System Stretch Tape is for. Note that stretch tape is not recognized for roof penetrations, only walls, windows and doors.
Installation notes
You need:
- A dry deck, free of frost, dust, dirt and proud fasteners
- A rubber-headed roller — in a valley, roll the centerline first and work outward to each plane
- Backer rod or similar backing in any gap wider than 1/2 in, before taping
- Air, substrate and tape all at 0°F or above at the time of application
- A plan for laps: shingle-lap upslope over downslope so water always runs over the joint, never into it
Do not use it for:
- A substitute for self-adhering ice and water barrier
- Fire caulking around heat-generating exhaust vents, such as dryer vents
Contractor and volume pricing
Roofing a subdivision or a multifamily building? Call (832) 463-7946 or email sales@85builders.com with your quantity and the job-site ZIP code and we will send pricing the same business day.
We accept Texas resale certificates for tax-exempt purchases.
Frequently asked questions
Can this replace ice and water barrier?
No. Huber is explicit that ZIP System flashing tape is not considered a substitute for self-adhering ice and water barriers in roof applications. Where code requires ice barrier, you still install ice barrier.
Why 12 inches for a valley?
It puts about 6 in on each roof plane in one piece, so there is no lap sitting in the trough where the water runs.
Is it approved for Type III construction?
Yes, specifically for taping ZIP System sheathing panel seams in roof applications. For everything else the listing is Type V.
How long can it stay exposed before the roofing goes on?
Up to 180 days, then it must be covered by a code-compliant roof covering.
Can I install it in freezing weather?
Down to 0°F, as long as the deck is frost-free and the tape and air are at or above 0°F too.
Is 12-inch overkill for wall work?
Usually. On walls the 9-inch covers outside corners and wide openings for less. The 12-inch pays off where one continuous piece across a wide detail is worth the price.
How fast does it ship?
We ship next business day from Cypress, TX.
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