Reading Roof Age + Condition Reference

Why this matters

Many service techs end up on the roof - HVAC for rooftop units, solar installers, gutter cleaners, satellite installers, even painters. They see the roof up close. Recognizing roof age + condition lets you flag concerns to the homeowner (cross-trade observation) + understand whether your work will affect roof integrity. The roofing tech does this routinely; the rest of us can learn the basics. This is the field card.

Roofing types

Asphalt shingle (most common US residential):

• 3-tab (older, lighter; ~20-year life)
• Architectural / dimensional (heavier; 25-30 year life)
• Designer / luxury (50-year life)

Metal roofing:

• Standing seam (50+ year life)
• Corrugated panels (varies)
• Common in agricultural + modern residential
• Higher upfront cost; longer life

Slate:

• Natural stone
• 75-100+ year life
• Heavy; requires strong roof structure
• Expensive

Tile (clay OR concrete):

• 50+ year life
• Mediterranean / Southwest common
• Heavy; structural considerations

Wood shake / shingle:

• Cedar typical
• 20-40 year life depending on climate
• Fire hazard in dry regions
• Treatment / maintenance required

Synthetic / composite:

• Various; rubber, plastic, polymer
• 40-50 year life
• Newer; less long-term data

Built-up (BUR) / modified bitumen:

• Flat roofs
• Tar + gravel OR membrane
• Commercial common; some residential

TPO / EPDM (single-ply membrane):

• Flat / low-slope
• Commercial common
• Color (white reflects, black absorbs)

Age estimation

For asphalt shingles (most common):

New (0-5 years):

• Sharp granule color
• All shingles uniform appearance
• Sealed tabs (lay flat)
• Bright flashings

Middle-aged (5-15 years):

• Some granule loss (lighter spots)
• Slight texture variation
• Mostly sealed; occasional lifting tab
• Flashings dulled

Older (15-25 years):

• Significant granule loss
• Visible texture / wear
• Lifting tabs common
• Curling at edges
• Flashings dull / starting to fail

End-of-life (25+ years):

• Heavy granule loss (gravel-like roof)
• Cracking / cupping shingles
• Many lifting OR missing tabs
• Visible underlayment in spots
• Replacement due

Visible failure signs

Granule loss:

• Loose granules in gutter / downspout
• Bare spots on shingles
• Sometimes called "balding"
• Major sign of age

Curling shingles:

• Edges curled upward
• Sign of age + heat damage
• Sometimes ventilation problem

Cupping:

• Center of shingle raised; edges down
• Reverse of curling
• Different failure mode

Cracking shingles:

• Hairline cracks visible
• Often along ridges + valleys
• Brittle from sun damage

Missing shingles:

• Wind damage usually
• Roofing nail pulled OR broken
• Visible gap to underlayment

Lifting tabs:

• Bond between tab + shingle failed
• Wind can lift more easily
• Often near ridges OR rakes

Algae streaks:

• Black streaks down the roof
• Algae growth
• Cosmetic primarily; doesn't damage structurally
• Some shingles algae-resistant (AR rating)

Moss / lichen growth:

• Damp / shaded areas
• Holds moisture
• Lifts shingles over time
• Should be removed (carefully)

Sagging roof line:

• Visible from ground
• Structural concern
• Rafter / truss damage OR sheathing failure

Light visible from inside attic:

• Holes in roof
• Failed flashing
• Significant water risk

Flashing condition

Chimney flashing:

• Step flashing along sides
• Saddle / cricket at top (some chimneys)
• Counterflashing into chimney mortar
• Failure: water in attic at chimney

Vent flashing:

• Rubber boot at vent pipe
• Cracks at boot common (UV degraded)
• Replace boot when shingles still good

Skylight flashing:

• Step flashing + apron + saddle
• Common leak source

Valley flashing:

• W-shape OR woven valleys
• Heavy water flow
• Erosion / corrosion possible

Drip edge / gutter apron:

• At eaves
• Directs water into gutter
• Missing = water into fascia

Penetrations

Anything that goes through the roof can leak:

Plumbing vent stacks:

• Rubber boots crack with UV
• Replace boot during reroof
• Lead flashings (some areas) last longer

HVAC vents / exhausts:

• Bath fan, range hood, dryer
• Improper flashing = leak

Skylights:

• Common leak source
• Flashing kits available
• Old skylights leak; replacement OR reflashing

Solar panel mounts:

• Bolts through roof
• Properly flashed by qualified installer
• Improper install = leak

Antenna / satellite dish:

• Mast mount on roof
• Sometimes leaks at base

Chimney:

• Multiple flashing components
• Common leak source
• Mortar deterioration around base

Cross-trade observations

HVAC tech rooftop unit:

• Walking the roof = damage if shingles old
• Avoid step on weak spots
• Note flashing condition around RTU
• Note ductwork penetration condition

Solar installer:

• Roof must be sound to support panels for 25+ years
• Old roof = recommend reroof BEFORE solar
• Customer's investment is at risk if roof fails

Satellite / antenna:

• Hole through roof must be flashed properly
• Old roof = consider risk

Gutter cleaner:

• Up close view of roof edge + drip edge
• Notes granule accumulation in gutter
• Observes overhanging branches

Cleaner washing exterior:

• Pressure washing damages shingles
• Soft wash safer
• Customer should know

Painter at fascia / soffit:

• Adjacent to roof edge
• May see edge condition
• Bad fascia = water entry

Algae + moss treatment

For cosmetic concerns:

Algae streaks (cosmetic):

• Bleach + water solution (1:1) sprayed; rinse
• Specialty cleaners available
• Don't pressure wash (damages granules)

Moss growth (active):

• Zinc OR copper strips at ridge (long-term prevention)
• Manual removal (brush; not pressure wash)
• Treatment products available

Re-occurrence:

• North-facing slopes most affected
• Tree shade contributes
• Trimming branches helps

When to recommend reroof

Definite reroof:

• Multiple visible leaks
• Widespread granule loss
• 25+ year-old 3-tab OR 30+ year-old dimensional
• Storm damage covered by insurance
• Structural issues

Plan within 2-3 years:

• 20+ year-old
• Showing significant wear
• Multiple repairs in last few years

Plan within 5 years:

• 15+ year-old
• Minor wear signs
• Plan for budget

Continue with maintenance:

• Less than 15 years
• Minor flashing issues
• Address spot repairs

Reroof considerations

Customer planning reroof:

Tear-off vs overlay:

• Tear-off (preferred): remove old shingles; inspect deck
• Overlay (one layer over existing): code allows in some cases; cheaper but doesn't fix underlying issues
• Most quality roofers tear off

Underlayment:

• Felt paper traditional
• Synthetic underlayment newer; better
• Ice + water shield at eaves + valleys (cold climate)

References

• ARMA (Asphalt Roofing Manufacturers Association)
• NRCA (National Roofing Contractors Association) standards
• ASTM D3462 (asphalt shingle standard)
• Manufacturer warranty + life expectancy data
• Manuall internal: Roof Underlayment Reference, Reading HVAC Age + Condition