How to Install Wakaflex Lead-Free Roof Flashing

Key Takeaways

Wakaflex should be installed on a clean, dry surface.
Joins require a minimum 50mm overlap.
The protective backing should be removed in stages as you work.
Wakaflex should be built into brickwork or mechanically over-flashed.

What Is Wakaflex Made From?

Wakaflex is a flexible lead-free flashing made from a layered laminate construction. It contains polyisobutylene, commonly known as PIB, an internal aluminium mesh and butyl adhesive strips along the underside edges.

The PIB body provides waterproofing and flexibility. The aluminium mesh helps the flashing hold its shape once dressed into the roof profile. The butyl adhesive strips help secure the material to the roof surface and create a tight seal at the edges.

Wakaflex is available in 5m roll lengths and comes in multiple widths, including 280mm, 370mm and 560mm. It can stretch up to 50% in length and 15% in width, which helps it form neatly over common roof profiles.

It is designed for common roofing applications including:

Abutments
Step-flashing
Chimneys
Roof/wall junctions
Skylights
Penetration flashing
Damp proof course
Cavity flashing

Wakaflex can be used on tile, metal and polycarbonate roofs where the application is suitable.

How to Install Wakaflex Roof Flashing

The basic Wakaflex installation process is simple, but pressure and surface preparation are critical.

1. Clean and dry the application area

Start by making sure the area is clean, dry and free from loose material. Adhesive performance depends on direct contact with the surface.

Remove mortar dust, concrete residue, paint debris, oil, dirt and moisture before laying the flashing.

2. Form Wakaflex to the roof shape

Before removing all the backing, form the Wakaflex to the basic shape of the roof profile.

This makes the product easier to position and helps reduce unnecessary stretching once it is placed on the roof.

3. Remove the protective backing in stages

Do not peel away all the backing at once.

Remove the top section first, place Wakaflex into position and fix the top butyl strip. Then slowly remove the remaining backing as you work across the roof detail.

This keeps the butyl adhesive clean and prevents it from sticking before the flashing is correctly aligned.

4. Press the top butyl strip into place

Once the flashing is positioned, press the top butyl strip firmly against the wall, brickwork or roof detail.

Use your hands or a small roller to apply even pressure. Firm pressure helps improve adhesion and reduces the risk of water tracking behind the flashing.

5. Dress Wakaflex into the roof profile

Press the material by hand into the roof surface. Stretch the internal aluminium mesh over the roof profile so the flashing sits tightly against the substrate.

For deeper profiles, a wallpaper roller can help apply consistent pressure.

Wakaflex should sit flush to the roof surface. Avoid large gaps or air pockets behind the material.

6. Press the lower butyl strip firmly

Once the flashing is dressed into the roof profile, press the lower butyl strip firmly against the roof surface.

This helps create the lower waterproof seal and reduces the risk of wind-driven rain getting beneath the flashing.

7. Overlap joins by at least 50mm

Where joins are needed, overlap Wakaflex by a minimum of 50mm.

Press the overlapping section firmly. Wakaflex adheres to itself immediately and cures permanently in approximately 15 to 20 minutes.

If you make a mistake, the lap can usually be peeled open within the first two minutes before the bond fully cures.

How to Install Wakaflex at Roof/Wall Junctions

Roof/wall junctions are one of the most common areas where water can enter a roof. The flashing must be detailed so water is directed out and away from the wall, not behind the cladding, brickwork or roof covering.

Wakaflex should be built into the wall detail or mechanically over-flashed. This helps stop water entering behind the top edge of the flashing.

For straight roof-to-wall junctions, dress Wakaflex across the roof profile and press it firmly into the surface. Pay close attention to the peaks of tiles or metal ribs so the butyl adhesive makes full contact.

Do not push the flashing deep into the troughs before securing the peaks. A good seal starts with firm contact across the highest points of the roof profile.

How to Install Wakaflex Around Chimneys

Chimney flashing needs careful detailing because water can enter from several directions. A typical chimney detail may include apron flashing at the front, stepped flashing along the sides, soaker flashing beneath roof coverings and a back gutter behind the chimney.

Wakaflex can be used as part of a chimney flashing detail when installed to suit the roof type and wall construction.

When installing around a chimney, make sure Wakaflex is firmly dressed into the roof profile and secured into the wall detail. The top edge must be chased into brickwork or mechanically over-flashed.

Pay close attention to corners. These areas are more likely to fail if the flashing is not pressed firmly, overlapped correctly or sealed against the adjoining surfaces.

How to Install Wakaflex at Abutments and Parapet Walls

Abutments and parapet walls need reliable flashing because they create a direct junction between the roof and a vertical wall.

The main goal is simple: stop water from tracking behind the flashing and direct it safely back onto the roof surface.

Wakaflex should be installed horizontally for abutments. It must be chased into the masonry or mechanically over-flashed to protect the top edge.

For tiled roofs, make sure the flashing bridges evenly across the tile peaks before being dressed down into the profile. This helps maintain a consistent watertight seal along the length of the abutment.

How to Use Wakaflex for Stepped Cavity Flashing

Stepped cavity flashing is used where a roof slope meets a wall and the flashing needs to follow the roof line in a stepped pattern.

This detail is common on tiled roofs, wall junctions and some cavity wall applications. It helps move water out of the wall cavity and back onto the roof surface.

When installing Wakaflex for stepped details, maintain the correct overlap and make sure each section is properly dressed into the adjoining roof profile. Wakaflex should be installed vertically for step-flashing applications.

Retrofitting Wakaflex Over Existing Lead Flashing

Wakaflex can also be used in retrofit applications where existing lead flashing is already in place.

There are two common approaches depending on the condition of the existing flashing and wall detail.

Option 1: Installing Wakaflex without fully removing existing lead

Lift the existing lead flashing as much as possible to expose the junction between the roof and wall.

Remove the top white section of the Wakaflex backing and adhere the material against the brickwork as close as possible to the underside of the existing lead flashing.

Use a roller or firm hand pressure to secure the butyl strip against the brick surface. Then remove the middle backing section and dress Wakaflex down firmly against the wall and roof surface.

Finally, remove the lower backing section and press the lower edge into the roof profile.

Once Wakaflex is in place, press the existing lead flashing back down over the top. The existing lead can act as an over-flashing, provided at least 50mm remains and is dressed firmly over the Wakaflex.

Option 2: Removing existing lead before installing Wakaflex

If the existing lead needs to be removed, cut it away with suitable metal snips as close to the wall face as possible.

Smooth or recess the remaining edge into the wall using appropriate tools. Wakaflex can then be installed into the newly recessed brick course and backfilled with mortar, butyl strip or a suitable sealant such as Sikaflex Pro.

This method creates a cleaner finish but may require more preparation. It should be carried out by a competent roofer, plumber or builder.

BAL-29 Installation Considerations

Roof finishing products such as flashing are not assessed in isolation for bushfire compliance. The roof system and site conditions must be assessed as part of the wider BAL requirement.

The Wakaflex guide states that Wakaflex lead-free flashing has been tested by CSIRO and assessed as suitable for BAL-29 regulatory requirements when correctly installed totally flush to the host roof system.

The key installation point is that cavities or voids must not be left between Wakaflex and the roof components. The flashing must sit flush against the host system, whether that is tile, slate, steel or another suitable roof material.

For bushfire-prone areas, always check the site BAL assessment, relevant construction requirements and installation guidance before work begins.

Common Wakaflex Installation Mistakes

Most flashing problems come from poor preparation, poor pressure or poor detailing.

Avoid these common mistakes:

Installing Wakaflex on a wet or dirty surface.
Removing all protective backing too early.
Leaving air pockets behind the flashing.
Not pressing the butyl strips firmly enough.
Failing to dress the material into the roof profile.
Using less than a 50mm overlap at joins.
Installing on a roof pitch below 12 degrees.
Applying masking tape to the Wakaflex surface.
Using silicone as a sealant.
Leaving mortar, concrete or paint debris on the surface.
Allowing loads to rest on or indent the Wakaflex.
Failing to chase the flashing into brickwork or mechanically over-flash it.
Leaving voids behind the product in BAL-29 applications.

Final Wakaflex Installation Checklist

Use this checklist before finishing the job.

Check Requirement
Surface condition Clean and dry
Minimum roof pitch 12 degrees
Join overlap Minimum 50mm
Backing removal Remove in stages
Pressure Press firmly by hand or roller
Roof profile Dress tightly into the surface
Top edge Chase into brickwork or mechanically over-flash
Sealant Do not use silicone
BAL-29 applications Install flush with no voids
Final inspection Check for gaps, lifting or air pockets

Get the Right Finish With Wakaflex

Wakaflex makes roof flashing faster, cleaner and easier to install when you need a lead-free solution for chimneys, abutments, roof/wall junctions and common tiled roof applications.

The key is correct preparation. Keep the surface clean and dry, remove the backing in stages, press the butyl strips firmly and use the correct overlap at every join.

Shop Wakaflex lead-free flashing or speak to the team for product advice before your next roofing project.

FAQs

Can I install Wakaflex over existing lead flashing?

Yes. Wakaflex can be retrofitted with existing lead flashing in place, provided the lead can be lifted and used as an over-flashing. The Wakaflex should be adhered close to the underside of the existing lead and dressed firmly into the roof profile.

What overlap does Wakaflex need?

Wakaflex requires a minimum 50mm overlap at joins. The overlapped sections should be pressed firmly together so the material self-fuses.

How long does Wakaflex take to cure?

Wakaflex adheres immediately and cures permanently in approximately 15 to 20 minutes. If a lap is positioned incorrectly, it can usually be peeled open within the first two minutes.

Can Wakaflex be painted?

Yes. Wakaflex can be painted after installation with a suitable outdoor acrylic paint.

Can I use silicone with Wakaflex?

No. Silicone is not recommended for use with Wakaflex. The installation guide refers to Sikaflex Pro polyurethane as a suitable additional sealant where required.

What roof pitch is Wakaflex suitable for?

Wakaflex should not be installed on roofs with a pitch below 12 degrees.

Does Wakaflex need to be chased into brickwork?

Yes. Wakaflex should be built or chased into brickwork, or mechanically over-flashed, to protect the top edge and prevent water from entering behind the flashing.

Is Wakaflex suitable for BAL-29 areas?

Can Wakaflex be installed by hand?

Yes. Wakaflex can be dressed into the roof profile by hand. A small roller can also be used to apply firm, even pressure where needed.

What surfaces can Wakaflex be used on?

Wakaflex is suitable for tile, metal and polycarbonate roof applications where the roof detail and installation conditions are appropriate.