Ceiling Spots
• Caused by leaks in roof
• Check attic or crawlspace for leaks in deck
• Check chimney and vents for cracks in flashing
• Check rafters for leaks that travel away from original source
• Check roof for damaged shingles  


Damaged Flashing
• Caused by improper installation
• Caused by drying and cracking
• Can usually be repaired without replacing roof  





Missing Shingles
• Caused by improper fastening
• Caused by exposure to high winds
• Can usually be replaced individually 
 
 



Buckling & Curling Spots
• Caused by improperly applied felt (buckling)
• Caused by movement in deck (buckling)
• Caused by undersaturation of felt in organic-based shingles (curling)  




Blistering
• Caused by moisture in shingles
• Caused by excessive use of asphalt plastic cement  




Algae Growth
• Caused by growth of airborne algae deposited on roof
• Unsightly appearance does not affect the service life of the material
• Common problem in warm, humid climates
• Algae resistant shingles available regionally 
 
 


Missing Granules
• Caused by absorption of moisture by mat at the core of the shingle
• Common problem with organic-based shingles  





Rotting
• On newly applied shingles, a certain number of loose granules is normal
• On aging shingles, missing granules indicate need for replacement