What Is Tear Strength in Asphalt Shingles?

Most homeowners judge a roof by what they can see.

Are the shingles:

• Missing?
• Cracked?
• Curling?
• Losing granules?

But roofing manufacturers and testing laboratories also evaluate physical properties that are much harder to see.

One of them is:

Tear strength.

ASTM’s asphalt-shingle specification includes tear strength among the physical characteristics evaluated for manufactured asphalt shingles.

For homeowners, the idea is straightforward.

Tear strength describes how well the roofing material resists being physically torn when force is applied.

Why Would a Roof Experience Tearing Forces?

Your roof is constantly exposed to mechanical stress.

Wind is one obvious example.

As wind moves across a roof, it can create uplift forces that try to lift roofing material away from the deck.

ASTM even has separate testing designed specifically to compare wind uplift forces against the mechanical resistance of installed asphalt shingles.

Other stresses can include:

• Storm debris
• Hail impact
• Installation loads
• Repairs
• Foot traffic
• Temperature-related movement

A shingle therefore needs more than the ability to shed water.

It needs enough physical integrity to remain intact while dealing with real-world loading.

What Happens as Shingles Age?

Asphalt shingles do not keep exactly the same physical properties forever.

A 2026 NIST durability study notes that shingles experience environmental stresses including:

• UV radiation
• Extreme heat
• Thermal cycling
• Freeze-thaw events

and that long-term weathering can affect how well shingles tolerate later mechanical loads such as wind and hail.

That is one reason an older roof should not be judged only by whether it currently leaks.

Material performance may already be changing.

Does Roof Rejuvenation “Repair” a Torn Shingle?

No.

If a shingle is already physically torn or broken, that is a roofing defect.

It may require:

• Localized replacement
• Repair
• Further investigation

Structural Roof Rejuvenation is intended for qualifying asphalt material that remains structurally viable.

It is not a substitute for replacing roofing pieces that have already failed.

Where Does NanoTech Fit?

NanoTech uses GoNano technology as part of a preservation strategy for aging but serviceable asphalt shingles.

GoNano reports testing that includes tear-strength and other mechanical-performance measurements as part of its broader evaluation program.

The important distinction is:

Preservation happens before severe physical failure.

If the material still has usable integrity, NanoTech can evaluate whether preservation makes sense.

If shingles are already badly torn, missing, or structurally compromised, those problems need conventional roofing work.

Why Homeowners Should Care

You do not need to measure tear strength yourself.

You need to understand the principle:

A roof can look intact while the material underneath is becoming less resilient.

That is why NanoTech focuses on actual roof condition instead of waiting until failure becomes obvious from the driveway.

A Roof Is Not Healthy Simply Because It Hasn’t Leaked Yet.

If your asphalt roof is aging and you want to understand how much serviceable material remains, NanoTech Exteriors can assess whether repair, preservation, or replacement is appropriate.