Can I Install a New TPO Roof Over the Existing Decking on My 2017 Keystone Montana?

Updated 10/21/2026 | Published 10/20/2026

Products Featured in This Question

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

(77)

$815.98

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

$461.95

Question:

I'm getting ready to replace the rubber roof on my 2017 Keystone Montana 3791RD fifth wheel. The old membrane is pretty worn but the plywood underneath looks solid from what I've checked so far. Can I reuse the existing decking with the Alpha Systems kit or does everything have to come off?

asked by: Jeff

Expert Reply:

Hey Jeff!

You can absolutely reuse your existing roof decking with the Alpha Systems SuperFlex Installation Kit # AL75EF as long as it's dry, solid, and free of rot or delamination.

You'll need to remove the old membrane, scrape away loose adhesive, and thoroughly clean the decking before installing the new one. A little old adhesive residue generally isn't a problem, but the surface should be as clean and smooth as possible.

For the new roofing material, I recommend the Alpha Systems SuperFlex TPO Roof Membrane # AL42CV 40' x 9-1/2' or the larger # AL62CV 45' x 9-1/2', depending on your actual roof measurements.

The installation kit includes the adhesive and sealants needed for the job, so pairing it with the appropriate membrane gets you the main materials for your roof replacement.

Have you already started removing the old membrane, or are you still gathering supplies?