Last updated: August 2026
Roof rejuvenation products are bio-based treatments that soak into asphalt shingles to restore flexibility. Most of the products on the market — including the well-known national brands — are soy-based. Ours is corn-based: a formula that is roughly 95% USDA-certified bio-based, third-party lab tested, and designed to penetrate the shingle and restore both flexibility and granule adhesion.
What is roof rejuvenation, and why is it "bio-based"?
Asphalt shingles are held together by oils in the asphalt that keep them flexible. Over years of sun and weather, those oils cook out, the shingle stiffens, and granules start to let go. Rejuvenation replaces some of what time takes away: a plant-derived treatment is sprayed on and penetrates the shingle rather than coating it, restoring flexibility so the shingle can keep expanding and contracting through Pennsylvania's freeze-thaw cycles without cracking.
The reason these products are "bio-based" is simple: the active ingredients come from agricultural crops rather than petroleum. That's the shared idea behind every reputable rejuvenation product. Where they differ is which crop the formula is built around.
What's the difference between corn-based and soy-based?
Both corn and soy oils can be refined into treatments that carry restorative oils back into a dried-out shingle, so at a high level the two approaches aim to do the same job. The difference is the base feedstock and the specific formula built on top of it.
Most competing rejuvenation products — including the large national brands many homeowners have heard of — are soy-based. Our treatment is corn-based instead. That's the honest, verifiable distinction: ours is corn-based; most others are soy-based. Neither is a gimmick, and we're not going to tell you soy doesn't work — it's a legitimate bio-based approach used across the industry.
What does the corn-based formula actually do?
Here's what we can say about our corn-based rejuvenant, backed by testing rather than marketing:
- Roughly 95% USDA-certified bio-based. The formula is built overwhelmingly from renewable, plant-derived content rather than petroleum.
- Works at the molecular level. It penetrates into the shingle and reaches the asphalt binder rather than sitting on the surface as a film or paint.
- Restores flexibility. By replenishing oils, it helps a stiff, aging shingle bend again instead of cracking under thermal stress.
- Restores granule adhesion. It helps the protective mineral granules hold their grip, which slows the granule loss that exposes the mat.
- Third-party lab tested. The performance claims are grounded in independent testing, not just our own word for it. You can read how that testing worked on our does it work? page.
Does the corn-vs-soy choice change the result for my roof?
For most homeowners, the practical takeaway is this: rejuvenation of any bio-based type is meant for the same kind of roof — asphalt shingles that are aging but still sound, generally around 6 to 20 years old, not leaking or storm-damaged. The corn-based formula is what we've chosen to use because of how it penetrates and the independent testing behind it, but it isn't a different service or a different promise. It restores flexibility and granule adhesion on a roof that's a candidate for treatment; it does not fix leaks, flashing, or missing and cracked shingles, no matter what crop it's made from.
If you've been comparing us against a soy-based national brand, the fairest way to think about it is that you're choosing between two bio-based treatments. We're confident in our corn-based formula and the lab results behind it — see how we stack up on our Roof Maxx alternative page — but we'd rather you pick based on the roof in front of you than on brand names.
How do I know if my roof is a candidate at all?
The formula only matters if your roof is actually right for rejuvenation in the first place. A treatment makes sense on an aging-but-intact roof, where restoring flexibility can add years of service life at a fraction of replacement cost. On a roof that's already leaking or failing, no rejuvenant — corn, soy, or otherwise — is the answer, and we'll tell you that plainly.
The only way to know which category you're in is to have the shingles looked at. Book a free inspection and we'll tell you honestly whether treatment is worth it for your specific roof.