Quick Take
Roofing, gutter, and waterproofing projects often come down to matching the right membrane to the surface you are protecting. These four listed options cover different jobs: a self-adhesive flashing roll for windows and door openings, a case of eight of that same flashing roll, a 108 sq ft PE underlayment roll for shower and wet areas, and a two-package seam tape for flooring underlayment seams. Listed prices run from USD 34.99 to USD 189.99, so the right pick depends more on the surface you are protecting than on price alone.
Listed Price Comparison
| Product | Listed price | Price bar |
|---|---|---|
| Henry FortiFlash Waterproof Flashing Membrane 1 Roll | USD 34.99 | |
| Henry FortiFlash Case/8 Rolls | USD 189.99 | |
| Shower 20 Mil Waterproofing Membrane 108 Sq. Ft | USD 63.27 | |
| Redgard TWO Seam Tape 5in x 16.5 ft | USD 49.99 |
Decision Matrix
| Use case | Best match | Why |
|---|---|---|
| Window/door flashing or non-roof horizontal sealing | Henry FortiFlash 1 Roll | Self-adhesive flashing membrane listed for windows, pot shelves, parapets, sill pans, recessed windows, and through-wall penetrations |
| Multiple openings or a large flashing job | Henry FortiFlash Case of 8 | Eight 6 in x 75 ft rolls in one case, same waterproof flashing membrane family |
| Shower walls, bathroom floors, steam rooms, wet areas | Shower 20 Mil PE Membrane | 20 mil waterproof and vapor barrier, 3.3 ft x 33 ft roll (108 sq ft), described as tile underlayment |
| Sealing seams in flooring underlayment | Redgard TWO Seam Tape | Lot of two 5 in x 16.5 ft red waterproofing membrane tapes for commercial and residential use |
Henry FortiFlash Waterproof Flashing Membrane 1 Roll
The Henry FortiFlash 1 Roll is a direct way to get a 6-inch by 75-foot flashing membrane for door and window work. The roll is white, described as waterproof and long-lasting, and weighs 6 lb. Its self-adhesive design is positioned for flashing around windows, pot shelves, parapets, sill pans, recessed windows, and through-wall penetrations. At USD 34.99, this is the lowest listed price in the group and a suitable pick if you need just one roll. The limitation is quantity: a single 75-foot roll will go fast on a project with multiple windows, so you may need additional rolls.
Henry FortiFlash Waterproof Flashing Membrane Case/8 Rolls
Henry FortiFlash Case/8 Rolls is the bulk version of the same 6-inch by 75-foot flashing membrane, sold as a case of eight rolls. It shares the waterproof, long-lasting feature set and the white exterior color, and the description points to the same uses: windows, pot shelves, parapets, sill pans, recessed windows, and through-wall penetrations. At USD 189.99, this is the highest listed price in the group, but it gives you eight rolls in one purchase. That works well for an extended flashing job or a house with many openings. The practical limitation is the case size: you need enough work to justify eight rolls for a smaller repair.
Shower 20 Mil Shower Waterproofing Membrane 3.3 Ft X 33 Ft Roll (108 Sq.Ft) - PE
The Shower 20 Mil Waterproofing Membrane is the listed option named for shower walls, bathroom floors, steam rooms, and wet areas. The roll measures 3.3 feet by 33 feet, which the listing translates to 108 square feet, and the 20 mil PE material is described as an underlayment with a vapor barrier for use under tile. The included component listed is the shower waterproof membrane itself, and the color is orange. At USD 63.27, it falls between the single Henry roll and the case on listed price. The limitation is that this is a PE membrane, not a flashing membrane, so it is not a direct substitute for exterior window or door flashing.
Redgard TWO Seam Tape 5in x 16.5 ft Commercial Residential Red Waterproofing Membrane
The Redgard TWO Seam Tape listing is a lot of two packages, each 5 inches by 16.5 feet. The tape is red, carries the waterproofing membrane feature, and is described as a flooring underlayment seam tape for commercial and residential use. At USD 49.99, this is the second-lowest listed price in the group. The practical limitation is that seam tape is a narrow strip designed for joints in underlayment, not a broad membrane roll. If the task is waterproofing entire wall or flashing surfaces, this tape is not the right choice.
Final Recommendation by Use Case
If you are flashing a few windows or door openings, the single Henry FortiFlash roll gives you a focused option at the lowest listed price. If you are planning a larger flashing job and want eight rolls on hand, the Henry FortiFlash Case/8 Rolls is the direct bulk equivalent. For shower renovations and wet areas, the Shower 20 Mil PE Membrane is the one designed for tile underlayment and vapor barrier use among these four options. If your task is specifically sealing seams in flooring underlayment, the Redgard TWO Seam Tape is the one to pick.
