Step flashing helps protect the joint where a roof meets a wall by directing water over the roofing rather than behind it. The right choice depends on the piece size, metal type, bend, and how many pieces your project needs. Below, we compare five options, from pre-bent aluminum pieces to copper flashing and bulk packs, so you can narrow down what fits your roof and installation plan.
| Product | Material and size | Pack size | Best suited for |
|---|---|---|---|
| Askoll Pre Bent Step Flashing | Aluminum, 2.5 × 2.5 × 7 inches | 100 pieces | Projects where pre-bent pieces and a compact profile fit the plan |
| Amerimax 68899 Flat Aluminum Step Flashing | Aluminum, 5 × 7 inches | 100 pieces | Those who want flat pieces to shape for their installation |
| Therwen Aluminum Roof Flashing Sheets | Aluminum, 5 × 7 inches | 120 pieces | Projects needing a larger pack of cut-to-size sheets |
| RDP Copper Step Flashing | 16 oz copper, 4 × 4 × 8 inches, pre-bent | 25 pieces | Installations calling for copper flashing |
| Amerimax 68800BX Aluminum Flashing Shingle | Aluminum; dimensions not provided | 500 pieces | Large projects where a high piece count matters |
Table of Contents
Our Picks: Best Step Flashing For Roof reviews
Askoll Pre-Bent Aluminum Step Flashing for a Ready-Shaped Option
Askoll’s set includes 100 aluminum pieces measuring 2.5 × 2.5 × 7 inches. The pre-bent shape is its main distinction: each piece comes formed rather than as a flat sheet that you need to bend yourself. That can make it a practical pick when the supplied dimensions and angle match your roof-to-wall detail.
The aluminum construction is lightweight and described as weather- and corrosion-resistant. The product description also mentions cutting and shaping, though changing the shape may require care to keep the flashing aligned with the roofing materials. Confirm the dimensions against your existing flashing or installation plan before ordering; this is a more compact piece than the 5 × 7-inch flat options below.
The pack size may suit a multi-course installation or a project where having extra pieces on hand is useful. But a larger quantity does not make it the right fit for every roof. Flashing must be installed in a way that works with the roof covering and wall detail, so follow the roofing system’s instructions or consult a qualified roofer if you are unsure.
Pros:
- Pre-bent form reduces the need to create the initial bend.
- Aluminum construction is lightweight.
- Includes 100 pieces.
- Product description says the material can be cut and shaped.
Cons:
- The 2.5 × 2.5 × 7-inch dimensions may not suit every roof detail.
- The listing does not specify aluminum thickness.
Verdict: Choose the Askoll set if its compact dimensions suit your installation and you prefer pieces that arrive pre-bent.
Amerimax 68899 Flat Aluminum Pieces for Flexible Shaping
This Amerimax pack contains 100 flat aluminum pieces measuring 5 × 7 inches. Unlike the pre-bent Askoll option, these pieces are supplied flat, so they may suit a project where the installer needs to form the flashing for the roof and wall junction. That flexibility also means shaping and fitting are part of the work.
The listing describes the product as easy to install and durable, but it does not provide a metal thickness or details about a pre-formed angle. Check whether the sheet size and material are suitable for your roofing system, and use appropriate metal-cutting and forming tools if adjustments are needed.
Compared with the smaller pre-bent pieces, the 5 × 7-inch format offers a larger flat sheet to work with. Compared with the Therwen pack, it contains fewer pieces. This makes it a straightforward option for shoppers who want a 100-piece aluminum pack and do not need the larger count.
Pros:
- Flat 5 × 7-inch pieces allow the installer to form the shape.
- Aluminum construction.
- Comes in a 100-piece pack.
- Product listing describes it as easy to install.
Cons:
- It is not listed as pre-bent, so shaping may add work.
- The listing does not specify material thickness.
Verdict: Consider this Amerimax pack if you want flat aluminum pieces and have a clear plan for shaping and fitting them.
Therwen 120-Piece Aluminum Sheets for Cut-to-Size Work
Therwen’s pack includes 120 aluminum sheets, each about 5 × 7 inches. The product is described as cut-to-size flashing for roof areas such as chimneys and skylights. For a step-flashing job, the key point is that these are sheets rather than a clearly specified pre-bent step-flashing profile, so you will need to confirm that they can be shaped and installed correctly for your particular roof detail.
The description says the sheets can be trimmed with tin snips and attached with nails, screws, or adhesive tape depending on the application. Those are general product details, not a substitute for the installation requirements of your roofing system. Choose a fastening and layering method that is appropriate for the materials and follow applicable instructions.
The 120-piece quantity is larger than the Amerimax 100-pack, while the sheet size matches the Amerimax 68899 listing. The product description notes that aluminum may discolor after long exposure to rain. That is worth considering if appearance matters, and it reinforces the importance of checking the material and finish for your intended use.
Pros:
- Includes 120 sheets measuring about 5 × 7 inches.
- Product description says the sheets can be cut with tin snips.
- Can be used for several roof-flashing applications, according to the listing.
- Flat sheet format allows sizing adjustments.
Cons:
- The listing does not identify these as pre-bent step flashing.
- The description notes that the aluminum surface may darken after prolonged exposure to rain.
Verdict: The Therwen set is worth considering when you need a larger pack of cuttable aluminum sheets and can shape them to meet your roof’s installation requirements.
RDP Copper Step Flashing for a Pre-Bent Copper Detail
RDP’s copper step flashing comes pre-bent at 90 degrees and is sold in a 25-piece bundle. The listed size is 4 × 4 × 8 inches, and the product description identifies the material as solid 16 oz copper. Its profile is intended for sidewall areas where the roof deck meets a wall, directing water back over the roof covering.
Copper sets this option apart from the aluminum choices in this roundup. It may be a fit when the project calls for copper, but it is important to make sure the flashing material works with the surrounding roof materials and project specifications. The smaller pack may also be a better match for a limited repair than a large installation requiring many pieces.
The supplied product data marks this item as unavailable, and the description says it is made to order with a lead time. Availability and fulfillment can change, so check the listing before planning your project around it. Its higher material specificity and pre-bent shape are useful advantages, but those details matter only if copper is appropriate for your roof.
Pros:
- Pre-bent at 90 degrees.
- Made from listed 16 oz copper.
- Designed for roof-to-wall sidewall applications.
- Bundle size is suited to projects that do not need a large quantity.
Cons:
- Only 25 pieces are included.
- The supplied data marks the product unavailable; confirm current listing status.
Verdict: Pick the RDP option if your project specifically calls for pre-bent copper flashing, but verify availability and material compatibility first.
Amerimax 68800BX Bulk Pack for High Piece Needs
The Amerimax 68800BX is listed as an aluminum flashing shingle in a 500-piece pack. The high quantity is its standout feature, making it a possible option for a large job or for buyers who need many matching pieces. The product data does not give dimensions or a detailed profile, however, so you should confirm those details before treating it as a direct substitute for a particular step-flashing specification.
The listing describes it as durable and easy to use but provides little information about the shape, thickness, or installation method. That makes this product harder to compare with the other choices, which include more specific dimensions or bend details. Check the product listing and match the pieces to your roof’s design before ordering a bulk quantity.
The supplied data marks this item as unavailable. If it becomes available, the pack size may be useful for a project with substantial flashing needs, but it is not the most informative choice for a small repair or for someone who needs a clearly stated size and bend.
Pros:
- Large 500-piece pack.
- Aluminum flashing shingle format.
- Product listing describes it as durable and easy to use.
Cons:
- Dimensions and profile are not provided in the supplied product details.
- The supplied data marks the product unavailable.
Verdict: This bulk pack may suit a high-volume project if its dimensions and profile match your plan, but the limited product details make verification essential.
How to Choose Step Flashing for Your Roof
Match the Shape to the Roof Detail
Step flashing is used where a roof meets a wall, with pieces layered alongside the roofing courses to help direct water outward. Some products arrive pre-bent, while flat sheets need to be formed. Check the intended profile and make sure it works with your roof covering, wall assembly, and installation instructions before buying.
Check the Piece Dimensions
Dimensions affect how a piece fits and overlaps with nearby materials. The products here range from compact 2.5 × 2.5 × 7-inch pre-bent pieces to flat 5 × 7-inch sheets and a 4 × 4 × 8-inch copper option. Do not choose by pack size alone: compare measurements with the flashing details required for your project.
Choose a Suitable Metal
The listed options are aluminum and copper. Material choice should fit the roof system and project specifications. The product details do not provide every compatibility or thickness detail, so check with the roofing-material manufacturer or a qualified roofer if you are uncertain about using one metal with another.
Decide Whether You Need Flat or Pre-Bent Pieces
Pre-bent flashing can save the step of forming an initial angle, while flat sheets offer room for shaping or trimming. Neither format is automatically the better choice: the right one depends on the required profile and the installer’s skill. Make sure the product description clearly states its shape before ordering.
Estimate the Quantity Carefully
Pack sizes in this group range from 25 to 500 pieces. Estimate the number of pieces needed based on the roof layout and installation plan, and allow for any cuts or mistakes. A large pack can be useful for extensive work, but it may leave you with unused material if you only need a small repair.
Review Installation and Product Details
Look for stated dimensions, material, bend, and installation guidance. Some listings provide more of these details than others. Use the roofing system’s instructions for fastening and layering, and do not assume that every flat flashing sheet is ready to use as step flashing without further shaping.
Frequently Asked Questions
What is step flashing used for?
Step flashing is used at a roof-to-wall junction. Individual pieces are installed in a layered arrangement with the roof covering to help direct water onto the roof surface rather than behind it.
Should I choose pre-bent or flat step flashing?
Choose the shape that matches your installation plan. Pre-bent pieces arrive formed, while flat sheets may need to be cut or shaped. Confirm the required profile and installation method before ordering.
Can aluminum flashing be cut to size?
The Therwen product description says its aluminum sheets can be cut with tin snips. For other products, check the listing and use tools and methods appropriate for the specific material and thickness.
Is copper flashing interchangeable with aluminum flashing?
Not necessarily. The products use different metals, and the correct choice depends on project specifications and compatibility with surrounding materials. Check the roofing system’s instructions or ask a qualified roofer if you are unsure.
How many pieces of step flashing do I need?
The needed amount depends on the length and layout of the roof-to-wall area, the piece size, and the installation plan. Measure the project and follow the roofing system’s guidance rather than choosing a pack based only on its piece count.
Can flat flashing sheets be used as step flashing?
They may need to be shaped and installed in a specific way to work as part of a step-flashing detail. A flat sheet is not automatically a ready-to-install, pre-bent step-flashing piece, so verify its intended use and profile first.
Conclusion
For a straightforward pre-bent aluminum option, the Askoll set is the clearest match in this group, provided its compact dimensions fit your roof detail. Choose the Amerimax 68899 or Therwen sheets if you need flat aluminum to shape, and consider the RDP bundle only when copper is specified and availability is confirmed. The Amerimax 68800BX has the largest pack, but its missing size details make checking the listing especially important. In every case, match the flashing to your roofing system and installation plan before you buy.
