Leak-Proof EPDM Flashing: DIY Techniques

What is EPDM roof flashing?

EPDM flashing tape is used to finish and waterproof various details of an EPDM roofing installation, including internal corners, external corners, pipers and drain outlets. With this in mind, this makes flashing tapes an indispensable tool for completing a professional-looking installation. 

In this blog post, we want to share more information about flashing tapes, how they can be used to improve the finish of an EPDM installation, and our tips and tricks for achieving a professional finish.

What is EPDM flashing used for?

As explained above, EPDM flashing has several uses, these include:

• Creating a waterproof seal on roof details, such as internal/external corners.

• Can be used to seal awkward angles, owing to its high malleability.

• Can be used as an inexpensive alternative to standard pipe boots.

It is vitally important to note that our EPDM flashings must be applied to clean and primed areas. We always suggest that one of our high-quality TRC EPDM primers is used to ensure the best results. 

What is the difference between EPDM flashing tape and EPDM seam tape?

Simply put, flashing tape can be used to finish any details found during an EPDM roofing installation, from internal/external corners to pipers and drain outlets. Its high flexibility makes it an indispensable tool for creating a watertight seal around upstands or edges.

Our range of seam tapes, on the other hand, is designed to be used when joining (splicing) rubber to rubber, creating a watertight seal where one piece of EPDM may not satisfy the project requirements, e.g. an “L” shaped roof.

Tips And Tricks For Achieving a Professional Finish With Flashing Tape

For a first-time installer, it may be intimidating to apply flashing tape, as its strong adhesive properties when mixed with the primer leave a very small margin for error; however, we’re here to try and take some of the stress out of the situation. 

For a professional finish, we suggest the following: 

1. Before applying primer to the EPDM, measure and mark the area needed with chalk.

2. Always dry-fit the flashing tape before applying primer, taking extra note of any complications which may arise, or any extra flashing tape which may be required (e.g., for tall external corners). 

3. When applying flashing tape, always start from the top and work down, taking special care to roll any air bubbles which may form out of the kit. 

4. Flashing tape by nature is extremely malleable, however in colder conditions, it may have much less manoeuvrability. In this case, apply a gentle heat source, such as a heat gun or hair dryer to help with stretching. 

5. Whether you’re applying a detail kit to an external/internal corner or another roof detail, a roller should be used to release any trapped air bubbles. 

6. When joining two pieces of EPDM with seam tape, always apply a thin layer of primer to both pieces to be spliced prior to placing the seam tape in position. 

We supply a range of high-quality flashing tapes, seam tapes and detail kits, friendly for both DIYers and contractors alike. 

If you’re struggling to find what you need to start your EPDM project, try our EPDM roof calculator, which will generate a quote based on your project requirements.

We also have a variety of posts on achieving a professional finish, as well as how-to videos and installation guides, ensuring you have everything you need to finish your DIY EPDM project to a professional standard.