step flashing installation

How to Install Step Flashing On Your Roof

Ensuring a robust step flashing system on your roof is vital for the overall well-being of your home. Moisture intrusion into walls, attics, ceilings, and floors can lead to detrimental issues such as mould, rot, insect infestation, and structural damage. Discover the proper step flashing installation techniques for roof step flashing to uphold a dry and well-maintained household. Learn about step flashing and how to install roof flashing to keep it safe on your roof and home.

Basics of Installing Step Flashing on a Roof

Roof flashing, a crucial waterproofing material, acts as a barrier, preventing water from infiltrating a building’s seams and joints. Specifically, step flashing is an upward building flashing variety that aligns with the roof pitch. It involves small pieces of interwoven flashing alongside shingles. Roof step flashing is typically crafted from materials like aluminium, copper, stainless steel, or lead.

In roofing systems, vulnerable spots for potential water infiltration are any joints or seams. This risk intensifies where the roof meets a vertical surface like a wall or dormer. Rainwater from the wall converges at the 90-degree junction with the roof. During snowfall, accumulated snowmelt in this region can seep between the wall and ceiling, leading to problems.

Attempts to seal shingles to the wall using tar, caulk, or similar liquid products are often short-lived solutions. These sealants degrade over time, permitting water entry into the building. The innovative design of L-shaped step flashing provides a flexible yet sturdy solution, adapting to the home’s movements while effectively preventing water infiltration at critical junctions.

Codes, Regulations, and Permits

In the majority of communities, you generally won’t need a building permit for a step flashing installation aimed at repairing the roof. However, if you’re incorporating the flashing during a roofing or re-roofing process, your community might mandate a building permit for the roofing project.

how to install roof step flashing

When to Install Step Flashing

During the installation of roofing shingles, step flashing is concurrently installed. When the shingles are already positioned, it becomes necessary to remove sure shingles to facilitate the step flashing installation. Therefore, ensure that step flashing is installed solely during dry weather conditions.

Safety Considerations

To correctly install step flashing, you’ll need to work on the roof, prioritizing safety to prevent falls. Ensure your safety by utilizing a fall arrest system and partnering with someone during the installation process.

What You’ll Need

Essential Equipment and Tools:

  • Tin snips
  • Ladder
  • Hammer

Materials Needed:

  • Pre-formed step flashing
  • Roofing nails


1- Remove Sections of the Siding:

Start by removing the lower sections of siding on the wall. Since step flashing typically extends about 8 inches up the wall, consider removing 10 to 12 inches of siding. This will provide you with enough space to work effectively.

2- Nail the First Row of Shingles:

Using a hammer and roofing nails, secure the first course of shingles. Remember to work from the bottom upward to ensure the shingles lay correctly. This initial row of shingles should slightly overhang the edge of the roof.

3- Position the First Step Flashing Piece:

First step flashing piece should extend from the roof to the wall. Position it horizontally so that it aligns with the shingle immediately below it.

4- Nail the Step Flashing Piece:

Secure the step flashing into the wall with two nails, approximately 1 inch below the top of the flashing. Important note: Avoid nailing the step flashing into the roof, as this could create additional entry points for water.

5- Nail the Second Row of Shingles:

Continue nailing down the second row of shingles, overlapping both the first row of shingles and the flashing.

6- Position and Nail the Second Step Flashing Piece:

Place the second flashing piece over the second row of shingles, aligning its left side with the left side of the second row of shingles. It should also cover the nails holding down the shingles. Secure the step flashing in place on the wall with two pins.

how to install roof flashing

7- Continue the Flashing to Completion:

Keep weaving the step flashing pieces and shingles in the manner described above until you reach the highest point of the wall on the roof pitch. The final row of shingles should complete the installation, with no whole step flashing pieces exposed.

8- Replace the Siding:

Once the step flashing is in place, carefully reinstall the siding on the wall, leaving about 1/2 inch between the top of the shingle/flashing and the bottom of the siding.

When to Call a Professional

Need help with step flashing but want a partial roofing overhaul? Roofing companies and repair services can handle installing or fixing step flashing in specific areas, not necessarily requiring a complete roof redo. If it’s step flashing for chimneys you’re after; your best bet is reaching out to a masonry company or a chimney specialist. They know the drill, especially since step flashing for chimneys usually involves precise mortar between those bricks.

step flashing installation


Q1: What is roofing step flashing?

Step flashing is a weatherproofing feature used in roofing to redirect water from the joints or seams between the roof and adjoining walls. It consists of short, L-shaped components of material, usually metal, that mesh with roofing shingles and the standing surface to control water infiltration.

Q2: Why is proper step flashing installation necessary?

Reasonable step flashing installation is essential as it guarantees adequate water drainage, preventing water from seeping into helpless areas like walls or roofing. It’s a necessary component of preserving a leak-free and long-lasting roofing system.

Q3: How is step flashing installed during a roof installation or repair?

During roof installation or repair, step flashing is typically established as shingles are laid. Each lesson on shingles is escorted by a piece of step flashing that interlocks with the shingles and the adjacent wall, providing a watertight seal.

Q4: Can step flashing be installed against a wall for chimneys or similar structures?

Indeed. Step flashing can be lodged explicitly against a wall, particularly for structures like chimneys. It concerns carefully setting the step flashing between the shingles and the wall, effectively controlling water penetration.

Q5: Can I install step flashing on my own?

While it’s feasible to install step flashing as a DIY scheme, it’s essential to have a good knowledge of roofing systems and correct installation techniques. If you need more clarification, it’s always suggested to seek professional help to provide proper installation and optimal waterproofing.

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