Is the Alpha Systems Roof Installation Kit Enough for a 40-Foot Fifth Wheel?

Published 10/20/2026

Products Featured in This Question

Alpha Systems SuperFlex RV Roof Membrane Installation Kit - Gray - 26' and Longer

$461.95

Alpha Systems Superflex TPO RV Roof Membrane - White - 45' x 9-1/2'

(77)

$815.98

Question:

I've got a 2020 Forest River Cardinal fifth wheel that's right around 40 feet long. I'm planning to replace the roof myself this fall and wondering if the Alpha Systems kit for 26 feet and longer will have enough glue and sealant for something this big. Id hate to get halfway through and run out.

asked by: Mike

Expert Reply:

Hey Mike!

The Alpha Systems SuperFlex Installation Kit # AL75EF is designed for larger RVs like your Cardinal, but with a 40-foot fifth wheel, I definitely recommend checking your roof measurements before getting started.

It includes 2 gallons of adhesive, 15 tubes of self-leveling sealant, 2 tubes of non-sag sealant, and 180 feet of butyl tape.

For the roofing material, I recommend the Alpha Systems SuperFlex TPO Roof Membrane # AL62CV, which measures 45' x 9-1/2'. That should give you some extra material to work with compared to the 40' membrane # AL42CV, provided your roof measurements fall within those dimensions. You want a little extra on the sides and front/back to wrap around the edges a bit.

Do you know your roofs actual length and width? I can help make sure you're ordering enough material before starting the project.

expert reply by: Andrew N