Do I Need Primer When Installing a New Superflex TPO Roof Membrane?  

Question:

Expert Reply:

Hello Patrick,

Great question.

You do not need to use a primer on a brand new Superflex TPO roof membrane like the Alpha Systems # AL83CV when applying lap sealant. As long as you’re using a sealant that’s compatible with TPO, it’s designed to bond directly to the membrane. Skipping the primer on a new, clean surface won’t increase your risk of leaks, so you can move forward with confidence there.

The key is making sure the surface is clean and dry before you apply the sealant. Even a new membrane can have a little dust or residue from handling, so giving it a quick wipe down helps the sealant adhere properly. Once it’s clean, you can apply a self-leveling lap sealant around roof openings like vents, skylights, and along edges, and it will flow out to create a watertight seal.

For the full install, you’ll want to make sure you’re using the right materials so everything works together. The membrane gets bonded down with Alpha Systems 8019 Water-Based Bonding Adhesive # AL54CV, which is designed specifically for TPO. After the membrane is laid in place, you’ll seal all penetrations and seams using a compatible self-leveling sealant like Alpha Systems 1021. If you run into any vertical seams or trim, switching to a non-sag sealant will help keep everything in place.

When reinstalling roof components, adding fresh butyl tape underneath them is just as important. It creates that initial seal before the lap sealant goes over the top and helps prevent leaks long term. Taking your time to smooth the membrane during install and making sure the roof decking underneath is solid and clean will also go a long way toward getting a good result.

If you’d rather simplify things, a full install kit like the Alpha Systems Superflex RV Roof Membrane with Installation Kit # AL99UV includes the main materials you’ll need and ensures compatibility across the board.

Did something bad happen to the roof, or just time to put down new due to age?

expert reply by: Kate F

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Parts Included with AL99UV
(click to enlarge)

Patrick D.

5/11/2026

I did order the AL69UV just waiting for it to ship I seen a video on internet saying it need primer just checking if needed so from what you said I don’t need it Thank you Patrick Donahue

Kate F.

5/11/2026

@PatrickD I would’ve double checked too, especially after seeing something like that online. There’s a lot of mixed info out there, but you’re on the right track. With the Superflex TPO and the kit you ordered, # AL69UV, you do not need primer. Everything in that kit is designed to work together and bond directly to the membrane as long as the surface is clean and dry, so you’re not risking leaks by skipping it. They were actually just out here doing a training not too long ago, and one of the biggest things they stressed was surface prep and working in smaller sections. Make sure you get the area cleaned really well before you start so the adhesive and sealant stick like they should. And when you’re laying it down, don’t try to do too big of a section at once. That’s where a lot of installs go sideways, because the adhesive can start setting before you get the membrane positioned and smoothed out. They also mentioned not to push down too hard when you’re working the membrane into place. You’re not trying to force it down, just gently work it so you can get the air bubbles out and make sure it’s making even contact with the adhesive underneath. If you take your time and work in manageable sections like that, it’ll lay down a lot cleaner and you’ll avoid wrinkles or trapped air. Good luck =)

Patrick D.

5/24/2026

Thank you Kate just wanted to make sure