Useful Life Expectancies

 

The following list may prove to be valuable in determining when various items in your home may 
require repair or replacement. The lack of maintenance will alter life expectancies. Normal 
maintenance is assumed in these estimations. This is to be used as a helpful guideline and 
there will be no liability assumed by either the inspection company or the inspector for its use. 
In the event that any specific components fail prematurely, warranties from the manufacturer 
and /or builder may apply. 

Expected life in Years 

Air Conditioning (Electric) 
Coil 15 to 20 
Compressor 5 to 15 
Fan 15 to 20 
 
Appliances 
Clothes Washer / Dryer 6 to 12 
Dishwasher / Garbage Disposal 5 to 12 
Oven / Range / Refrigerator 10 to 20 
 
Electrical System 
Service Entry Cable 20 to 40 
(depends on exposure to sunlight) 
Panel Box - Breaker and Fuse 20 to 50 
(depends on amount of moisture 
in the area of box and contacts) 
Wiring - interior, copper 
    Armored Cable (BX) 75+ 
    Cloth Sheath (Standard) 30 to 60 
    Knob and Tube 50 to 75 
    Plastic Sheath (Romex) 75+ 
 
Heating System 
Boiler 
    Cast Iron 30 to 50 
    Steel 30 to 40 
Circulating Pump 10 to 15 
Expansion Tank 5 to 10 
Exposed Duct Work 20+ 
Fan 10 to 40 
Gas Furnace 15 to 25 
Heat Exchanger 15 to 30 
Heat Pump (electric) 20 to 25 
Humidifier 5 to 10 
Oil Furnace 20 to 30 
Oil Tank (inside of home) 25 to 50 
Pipe 
    Copper 60+ 
    Steel 70 to 100 
Zone Valves 5 to 10 


Plumbing 
Interior Service and Drain Lines 
    Cast Iron 30 to 50 
    Copper 10 to 50 
    Galvanized Steel 30 to 50 
    Lead 40 to 80 
    Plastic (PVC, ABS, PB) unknown 
 
Roofing 
Asphalt Shingle 
    regular 15 to 20 
    multi-thickness 20 to 30 
    interlocking 15 to 25 
Built-Up (per ply) 2 to 4 
Cement Asbestos 30 to 75 
Clay Tile 20+ 
Metal 15 to 40 (tin-recoat every 5 years) 50 to 90 
Roll 10 
Slate (depends on grade) 30 to 100 
Wood Shake/Shingle 10 to 40 
 
Siding 
Aluminum 20 to 30 
Asbestos 20 to 75 
Brick / Block / Stone 100+ 
(may need periodic pointing) 
Hardboard/Composition 5 to 10 
Stucco 70 to 100+ 
T1-11 Plywood with regular coating 10 to 20 
Vinyl 30 to 50 
Wood Shake / Shingle 5 to 15 
 
Structural Components no limit 
(depends on design, construction 
and human living conditions) 
 
Water Heater 
Electric 10 to 15 
Gas 8 to 12 
Oil 10 to 20