How To Look At A House

McGarry and Madsen's home inspection blog for buyers of  

site-built, mobile/manufactured and modular homes

What is the average lifespan of an architectural (dimensional) shingle roof?

Saturday, August 25, 2018

The expected lifespan of an architectural asphalt shingle roof, often called a dimensional shingle roof, is 24 to 30 years in Florida, with an average of 27 years.  Architectural shingles start with a heavier mat base than a standard 3-tab shingle, typically fiberglass that has been coated with asphalt. Multiple layers are then overlapped and laminated together to create the distinctive texture. The finished product weighs about 100-lbs. more per “square” (a roofer’s term for 100 square feet of roof area) than regular shingles. Builders also like them because minor imperfections in the roof deck are concealed by the texture.

   If you currently have a regular shingle roof, most realtors we know recommend upgrading to architectural shingles when it’s time for a roof replacement, because of the all-important curb-appeal boost it gives an older home.

   This graph compares average lifespan of an architectural shingle roof to other roof types:

   The lifespan estimate is based on “average” conditions, and 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.

    Go to our blog post What is the average lifespan of the parts of a house? for rating of other house components.  

• • • • • • • • • • • • • • • • • • • • • 
Field Guide for Home Inspectors, a quick reference for finding the age of 154 brands of HVAC systems, water heaters, and electrical panels, plus 210 code standards for site-built and manufactured homes, and the life expectancy rating of 195 home components. Available at amazon.com for $19.95.
• • • • • • • • • • • • • • • • • • • • • • 
 

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

• What are common problems of asphalt shingle roofs?

Why is my roof sheathing sagging between the trusses?

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

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? 

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'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?  

    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.

Water Heaters

Water Heater Age

"What Are The

Signs Of..."

Septic Tank Systems

Structure and Rooms

Plumbing Pipes

Termites, Wood Rot

& Pests

Sinkholes

Stairs

When It First

Became Code

"Should I Buy A..."

Park Model Homes

Site

Shingle Roofs

Safety

Stucco

Remodeling

Wind Mitigation

Roof and Attic

"Does A Home

Inspector...?"

Pool and Spa

"What Is The Difference Between..."

Radon

Brick

Plumbing

Concrete and

Concrete Block

Metal Roofs

Foundations

Modular Homes

Rain Gutters

Mold, Lead & Other Contaminants

Condominiums

Older and

Historic Houses

Crawl Spaces

Mobile-Manufactured Homes

Building Permits

Life Expectancy

Clay Soil

Insurance

Floors

Insulation

Toilets

Exterior Walls

& Structures

Generators

Common Problems

HUD-Code for

Mobile Homes

Garages and Carports

Flat (Low Slope) Roofs

Electrical Panels

Sprinkler Systems

Electrical Receptacle Outlets

4-Point Inspections

Hurricane Resistance

Frequently Asked Questions (FAQ)

Home Inspection

Heating and Air Conditioning

Building Codes

Fireplaces and Chimneys

Inspector Licensing

& Standards

Energy Efficiency

Washers and Dryers

Electrical

Kitchens

Doors and Windows

(placeholder)

Cracks

Electrical Wiring

Click Below  

for Links

to Collections

of Blog Posts

by Subject

Plumbing Drains

and Traps

Appliances

Smoke & CO Alarms

Aging in Place

Top 5 results given instantly.

Click on magnifying glass

for all search results.

Bathrooms

Lighting

AFCI, CAFCI,

DFCI, & GFCI

Sinks

Air Conditioner & Furnace Age/Size

Attics

Electrical Switches

Siding

Search

This

Site

Water Intrusion

Electrical - Old

and Obsolete

(placeholder)

Foundation Certifications

Tiny Houses

About McGarry and Madsen

(placeholder)

Wells

Buying a home in North/Central Florida? Check our price for a  team inspection by two FL-licensed contractors and inspectors. Over 8,500 inspections completed in 20+ years. In a hurry? We will get it done for you.

Moisture Problems

Crawl Spaces

Bedrooms

Closets