Raised shingle tabs occur when the individual lower edges or tabs of asphalt shingles lift away from the roof deck rather than lying flat and secured. This condition can be visible as curled, warped, or lifted shingle tabs.

Common Causes of Raised Shingle Tabs:

1. Poor Installation:
   Improper nailing (nails too high, too low, or missed) can cause shingles not to adhere properly.
   Incorrect adhesive strip activation or lack of sealant during installation.

2. Age and Weathering:
   Shingles naturally lose flexibility and adhesion over time due to UV exposure and heat cycles.
   Thermal expansion and contraction cause shingles to lift or curl.

3. Moisture Issues:
   Excessive moisture trapped beneath shingles from poor attic ventilation or roof leaks can cause shingles to warp or tabs to raise.
   High humidity can soften adhesive strips, reducing their bonding strength.

4. Wind Damage:
   Strong winds can physically lift and loosen shingles, especially at edges and corners.
   Repeated wind exposure weakens adhesion and loosens nails.

5. Manufacturing Defects:
   Inferior or defective shingles with poor sealant strips or inadequate granule adhesion.

6. Roof Deck Problems:
   Uneven or warped decking can prevent shingles from lying flat.
   Structural movement or settling may shift shingles.

7. Improper Ventilation:
   Poor attic ventilation leads to excessive heat buildup, accelerating shingle deterioration and causing tabs to lift.

Potential Consequences of Raised Shingle Tabs:

Minor Issues:

• Aesthetic Damage: Raised tabs can cause the roof to look worn, aged, or poorly maintained.

• Loss of Granules: Raised tabs are more prone to granule loss, reducing UV protection and shortening shingle life.

• Minor Water Intrusion: Small amounts of water may seep beneath the shingles during heavy rain or wind-driven rain.

Moderate Issues:

• Increased Risk of Wind Damage: Raised tabs can catch wind more easily, increasing the likelihood of shingle blow-off or further lifting.

• Reduced Energy Efficiency: Lifted shingles may reduce the effectiveness of roof insulation by allowing heat exchange.

• Potential for Mold and Algae Growth: Moisture trapped beneath lifted tabs can encourage mold, mildew, and algae growth, leading to staining and possible health concerns.

Major Issues:

• Water Infiltration and Leaks: Raised tabs can allow significant water entry during storms, leading to interior water damage, stains, and structural deterioration.

• Roof Deck Damage: Prolonged water intrusion may cause rot, warping, or weakening of the roof decking.

• Compromised Roof Integrity: The overall roofing system may fail prematurely, requiring partial or full roof replacement.

• Structural Damage: If leaks persist, underlying roof framing and interior ceilings/walls may suffer damage, potentially leading to costly repairs.

• Mold Infestation: Persistent moisture can lead to serious mold problems inside the attic or living spaces, affecting air quality and health.

Summary:

Raised shingle tabs are a common roofing defect with multiple causes ranging from installation errors to natural aging and environmental exposure. While minor in appearance initially, they can progressively lead to significant water intrusion and structural damage if left unaddressed. Prompt identification and repair can prevent costly roofing failures and protect the building’s structural integrity.