To treat or not to treat?

🌿 Soy-Based Roof Rejuvenation: Does It Really Work?

By Pacific Sierra Roofing | Nanaimo BC

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🏠 The Straight Talk on Soy Roof Sprays

You’ve probably seen ads about soy oil roof treatments that claim to make old shingles “like new again.”

We’ve had a few customers ask if it’s legit or just another gimmick. Here’s what we’ve actually seen out in the field.

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🌿 What These Sprays Really Do

Asphalt shingles have natural oils that keep them flexible.

Over the years, the sun and weather cook those oils out — and once they dry up, the shingles start cracking, curling, and losing granules.

Soy-based rejuvenators are meant to replace some of those lost oils. The spray soaks into the surface and helps the shingle regain a bit of flex.

Kinda like putting oil on an old baseball glove — you’re not making it brand new, but you’re keeping it from stiffening up and splitting.

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⚙️ What’s In It

Most of these products (like Roof Maxx and a few others) use soy methyl esters, made from real soybeans.

They’re biodegradable and non-toxic, which makes them a cleaner alternative to petroleum-based sealers.

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🧰 How It’s Applied

A tech sprays it on using low pressure — no fancy equipment needed.

It soaks in over the next hour or so, and by the next day the roof’s dry to walk on again.

Manufacturers claim it can extend roof life five to ten years, depending on how old and dry the shingles were before treatment.

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🔍 Real-World Example From Nanaimo

We checked out two identical homes in the same townhouse complex here in Nanaimo — both built the same year, both with the same shingles.

• One homeowner treated their roof with soy oil about five years ago.

• The other didn’t bother.

Here’s what we found:

• The treated roof still looks tight. The granules are hanging on, and the shingles flex a little when you lift the edge.

• The untreated one… not so much. You can see heavy granule loss in the gutters and at the bottom of the downspouts, plus some fine cracking on the south-facing slope.

Side by side, the treated roof aged slower, plain and simple.

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25 year malarkey shingle roof without treatment

25 year malarkey shingle roof with treatment five years prior to taking photo

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💰 Pros and Cons

👍 Pros

• Roughly 10–15% of the cost of a full replacement

• Non-toxic, safe for gardens and pets

• Can buy you a few extra years before needing a tear-off

👎 Cons

• Won’t fix leaks, curled shingles, or missing tabs

• Has to be redone every 5–7 years for best results

• Results vary with roof age, exposure, and who applies it