Estimating roof age

With all the variables in how long a roof can last, (pitch, ventilation, installation, materials, ect) I am wondering what is the best way to estimate the age and life expectancy of a roof. I have been using older, average, or newer. I know some that use ranges like 12-17 years old, less than 5 years left ect. what do some of you do?

one tip that can be very helpful is to look at the sellers



I agree with Carla on this. I have seen many roof structures that appeared brand new that were 10 years old and many that were at their life expectancy and only several years old. There are so many variable factors in this area that I do not try to make an educated guess without the owner telling me or having the permit for the roof or a receipt for the roof replacement. Just my 2 cents.


I do not guess at anything, especially roof coverings. I do not comment at all with regard to the age. I do explain a roof covering is only as good as the material it is made of, and how it may have been installed (right or wrong), by looking at it.

Just the existing condition at the time of inspection is noted, with the type and how I inspected it.

my method is an ancient Chinese secret. and if i told you i’d have to kill you, and i don’t want to go to jail for murder…again. ha

I also agree - its dangerous and too risky to guess, or be wrong and held liable. Leave it to the professionals that are reputable roofers. We recently had a 3rd generation roofer talk to our meeting group about this topic of determining age and remaining life of a roof shingle - more particularly asphalt and fiberglass. First he cautioned against it for many reasons particularly today with inferior quality even in the production and manufacturing stage. It’s simply guesswork and he recommended shorter life expectancies are his experience. It’s risky!

In addition even through his decades of experiece a 25 year asphalt shingle might get 10 to 15 years, possibly better on other factors such as substrate, installation quality, details, and once again quality of materials. He stated market oil prices has also had a dramatic impact on the quality - where the costs of manufacturing is replaced with inferior products, and poorer quality materials used in the manufacturing process in order to maintain profits margins. Even small details such as hand nailing versus power nailing can be an important issue depending on the type shingle for workmanship in the field.

Also home resales are well known and tend to also influence the manufacturer’s mind set of the real life expectancy of asphalt shingles. Home owner changesare used indicating average turnover rates often are shorter or near to the 10 - 15 year realistic life cycle span of the often touted 25 year shingle claim by the manufacturer. In many cases change of ownership = loss of warranty coverage. Besides how many home owners still have their warranty anyway? Likely very few.

I only estimate age if the client asks and then owner isnt sure and then I overestimate to be safe. Last week at an inspection the owner did state the roof was “only” 10 years old but it had some curling and nail popping and the vent and chimney flashing was in real bad shape too so I estimated the age at 15 to 20 years.

i usualy “guess” and then add 5 yrs. if i see the underside of the shething is dark, i add more. if it’s 2 layers i add 10. that’s to the age not time left. but like you said Darrel, over guessing to be safe is good to. just don’t go too far and say that a 10yr old roof with new sheething and no other visual defects needs to be replaced. i dought you would, but i know lots of people read these post and take it way to literaly.

No age estimates. Only the apparent condition at the time of inspection.

If the granules are almost gone, cupping and curling usually mean the roof has reached the end of it’s useful life and needs to be replaced.

Exposed nail heads are often a sign of incorrect installation.

If the roof is functioning as intended but appears to be aging, I recommend the client budget for a replacement in the near future. The realtors love this one.

Erol, when the client or agent asks you a time frame for the “near future”? what do you say. 5-10 yrs, 1-5 yrs, isn’t that a guess on life of a roof? i understand generalising and i practice it whole hartedly, but it’s realy difficult to avoid the numbers.

Have a licensed roofing contractor look at it and tell you.

Wow, I guess I’m the only HI out there that has been giving their clients the guess-timated roof age of their prospective home. I’m always telling my clients how old their roofing material appears to be.

I can say, that I’m pretty good at guessing the age of asphalt. There have been many times where the listing Realtor looks at the disclosure or listing and will tell me that my guess is right on. I’m usually correct within a three or four year window.

I am with you David. I write the roof appears to be approximately so many years old. I do not tell them how long their roof will last.

I guesstimate the age of shingle, flat, tile etc.

I use the “useful life” term:

Appeared to be in the first half of its useful life.
Appeared to be at the midpoint of its useful life.
Appeared to be in the second half of its useful life.
Appeared to be nearing the end of its useful life.
Appeared to be at the end of its useful life.
Appeared to be past the end of its useful life.

I once marked a roof down as being near the end of its useful life. The sellers were furious, claiming that they had the roof replaced just two years ago. And they even had the receipt to prove it. Unfortunately, the picture shows what they had done that had caused the roof to age rapidly. All the soffit vents and gable vents also had been sealed tight. Keep in mind that we have 11 months of sunshine here, as well as lots of hot, dry Santa Ana winds. This 10-year roof had simply burned up from lack of ventilation in the attic. The roofing company voided the warrant because of the homeowner modifications.

TurbineVent1 (Small).jpg

So…All in all, the roofing material was still (as you stated) “being near the end of its useful life”, whether it was two years old or not.

You were still correct in your statement. I could care less how furious Sellers get when I claim a defect. When I find a defective roofing material (even if it’s two years old)…The roof needs to be replaced…Period.


My point, though, was that if I had guesstimated that the roof was 30 years old (and that’s how old it looked) I’d have been wrong. It was only 2 years old. I think that would have created more problems. But by simply saying that it was nearing the end of its useful life, the age of the roof really doesn’t matter. That’s the beauty of those statements which, by the way, were provided to me by my attorneys and endorsed by my E&O insurance provider.

I never ever guess the age of anything because extenuating circumstances can alter the looks of just about anything.

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I don’t guess the age of the roof, As I stated earlier,*** I’m always telling my clients how old their roofing material appears to be.

You can simply find a young 2 year old roof that appears to be 20 years old due to inadequate ventilation.

Appears to be is my keyword.

Straight from Inspectvue.

I also would not say anything about the remaining life. If the roof needs repair I recommend a roofer. A roofer will certify a roof here in AZ if it has 2 years of life left. A roof with 2 years of life left is pretty rough.

Idle curiosity. Was any reason given for sealing the vents? Would love to hear how they got to that point.

They thought they could lower their utility costs if they sealed the attic.