What is the average lifespan of a regular (3-tab) shingle roof?

Saturday, August 25, 2018

The expected lifespan of a 3-tab asphalt shingle roof, often called a 20-year shingle roof, is 16 to 22 years in Florida, with an average of 19 years. Why does a roof shingle with a 20-year manufacturer’s warranty typically last less than 20 years? Because the warranty is against “manufacturer’s defects” during the period of the warranty, not for the actual life of the roofing components used, of which the shingles are just one component. Poor workmanship by the roofing contractor is often determined to be the cause of early failure of a roof if a claim is made against a roofing material manufacturer.

   The 16 to 22 year average lifespan estimate is based on “average” conditions. Many factors contribute to a longer or shorter life of the roof; so a particular shingle roof’s life can vary—sometimes significantly—from the average. Here’s a list of conditions that affect roof longevity:

Color of roof - A dark roof absorbs more heat, which shortens the lifespan.

  • Angle of roof slope - Higher pitch roofs tend to last longer.
  • Orientation of roof surface - A roof slope facing south will get more sunlight, and have a shorter life.
  • Multiple-layer roof - A roof installed over an existing roof will have a shorter life. Two layers of shingle roof are allowed by building codes, so it is possible to put a new shingle roof over an existing one—just once. While a homeowner saves the tear-off labor and dump fees for removal of the old roof, the shorter life of the new roof and double expense of the tear-off and dump fees when its time for a roof again make it a poor long-term choice. 
  • Quality of roof material - “Economy” roof materials have a shorter life.
  • Installation - Sloppy or improper installation shortens roof life. Manufacturers typically blame the roofing contractor for a roof that has a short life, and they are sometimes correct. Exposed fasteners, over-driven fasteners, and poor or missing flashing at valleys and edges will shorten the roof life.
  • Attic ventilation - An unventilated or poorly ventilated attic reduces roof lifespan.
  • Radiant Barrier - The foil sheet glued to the underside of roof sheathing to reflect the heat of the sun back out into the atmosphere—reducing the attic temperature in the summer—tends to also reduce shingle life because it makes the roof shingles hotter. 
  • Trees near roof - Tree branches rubbing on a roof or the acidity from the accumulation of leaf debris on a roof shortens its life.
  • Harsh climate - Severe weather, both harsh winters and hot summers, along with big temperature swings within a 24-hour period, also shorten lifespan because of the expansion and contraction of roof materials.

    Here’s a bar graph comparing a 3-tab shingle roof life expectancy of other types of roof coverings.
    Go to our blog post What is the average lifespan of the parts of a house? for rating of other house components. To understand the basis, potential use, and limitations of lifespan ratings, see our blog post ”How accurate are the average life expectancy ratings of home components? Are they actually useful? 

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  To learn more about roofs and attics, see these other blog posts:

Why is my roof sheathing sagging between the trusses?

Why is granule loss a problem for an asphalt shingle roof? 

What are the mistakes to avoid when doing attic improvements?

What causes roof shingles to curl up at corners?  

What causes shingles to buckle along a line on the roof?

What causes leaks at a fake roof dormer? 

What causes a sagging roof ridge line?

What causes bubble-like blisters in a built-up and gravel roof?  

Why does it cost so much more to replace a steep roof than a low slope roof? 

What is "ponding" on a flat roof?

Is an attic required to have a light by the building code? 

How can I inspect my roof for hurricane damage?

Why is premature curl of roof shingles a problem?

How can I tell if a roof has more than one layer of shingles? 

What are the common problems with attic insulation? 

What is the life expectancy of an asbestos cement shingle roof? 

What's the average lifespan of a roof?

Why is it a mistake to replace a roof and not replace its flashings? 

Why is there no attic access hatch in the house?

What is the building code requirement for an attic access hatch, scuttle, or door? 

Does a roof with multiple layers of shingles last longer?

What can I do to prevent roof leaks?

Are roof trusses better than roof rafters (stick framing)? 

Why is a popped nail in a shingle roof a problem? How do I fix it?

What are the most common problems with wood roof trusses?

What causes a lump or dip in the roof? 

If my roof is not leaking, why does it need to be replaced?

How can I be sure my roofing contractor got a permit?

How many layers of roofing are allowed on a home? 

What are the dark lines running parallel to shingles on my roof?

Can metal roofing be used on a low slope/pitch roof? 

How can I make my roof last longer?  

What are the warning signs of a dangerous attic pull-down ladder?

How can I find out the age of a roof? 

Should I buy a house that needs a new roof?

Should I buy a house with an old roof? 

What are those metal boxes on the roof?

What does "lack of tab adhesion" in an asphalt shingle roof mean?

Why do roof edges start leaking?

Why do my dormer windows leak? 

Do home inspectors go on the roof? Do they get in the attic?

Should I put gutters on the house? 

How much of a roof truss can I cut out to make a storage platform in the attic? 

What's the difference between an "architectural" and a regular shingle roof? 

What does a home inspector look for when examining a roof? 

Do stains on the ceiling mean the roof is leaking?

How can I tell if the house needs a new roof?  

 Why does my homeowner's insurance want a roof inspection?

What are the hazards to avoid when going into an attic? 

    Visit our ROOF AND ATTIC  and LIFE EXPECTANCY pages for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles. 

NOTE: These life expectancies are based on data provided by InterNACHI, NAHB, FannieMae, and our own professional experience. Because of the numerous variables that can affect a lifespan, they should be used as rough guidelines only, and not relied upon as a warranty or guarantee of future performance.

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