Estimating The Age Of Asphalt Shingles?

[AbsoluteInspector]

I am a home inspector for about two years now in the Saint Louis area.

One thing I have had a very difficult time with while trying to constantly become a better inspector is estimating the age of the roof shingles, and it seems to be one of the most common questions I get.

I can obviously tell when shingles are at or near the end of their useful life and I can also tell when they are less than six months old or so but everywhere in the middle is very hard for me to be sure and I often try to guess if my client really wants to know (while also notifying them that I can in no way be certain) but I don't want to have to guess at all.

How confident are some of you at estimating the shingle age and how do you do it and how do you express that to your client?

[Marc]

I don't guess the age of shingles. I just report their condition and sometimes tell them what to do if anything.

Marc

[kurt]

Age doesn't matter so much. Drainage, underlayment, valley liners, drip edge, flashing details, and all that other stuff the shingle mfg's. don't talk about does matter.

Everyone thinks shingles are the most important part of a roof and that they last 20 years. Not so.

Roofing performs as well as it drains. The same shingle, installed on a 3:12 pitch and a 10:12 pitch will have vastly different performance life. Same with flashing details.

So, like Marc, I don't think about age too much. I only report it because people expect me to.

[AHI in AR]

The plumbing vent flashings that are the all black type plastic/rubber units often have the year, month and day of their birth stamped on them. They're usually a good clue IF there are no indications that they are older or newer than the shingles. They don't last as long as most shingles, though, so that isn't an infallible method. In other words, the shingles may be older but it's less likely that the shingles are newer since common practice is to install all new flashings when reroofing.

[John Kogel]

Say it has 15 to 20 year shingles on a sloped gable roof.

If you have an exact date the house was built, like 1972, then you know the house is 43 years old and the roof you're looking at is either the old second roof or the 3rd roof.

If the roof is multiple layers, I count about 25 yrs for Cedar shingles and 15 years for each layer of asphalts. Tear it all off.

Newer house, how old is the house? Easy one. []

[palmettoinspect]

Checking for old nails holes in the roof sheathing can help also to determine if the roof has been replaced or not. It's not always reliable though.

[Steven Hockstein]

I agree with Marc and Kurt. I would also suggest that your client inquire about the history of roof replacement and past leaking issues that may have been repaired and/or concealed. Recommend that they request the documents from the owner. Around here you need a permit to replace the roof so they can also request the information from the local construction department (assuming the proper permit was obtained).

[Jim Baird]

Roof cover age is often disclosed if the seller has been an occupant. Just as with gardening where every location is a local climate, every roof faces its own challenges to its guard duty for the building.

I just do the best I can to describe what I see.

[palmettoinspect]

Roof cover age is often disclosed if the seller has been an occupant. Just as with gardening where every location is a local climate, every roof faces its own challenges to its guard duty for the building.

I just do the best I can to describe what I see.

The "sellers disclosures" around here are hardly worth the paper they're written on and often seem like an outright lie. I'm sure some try and truthfully fill theirs out, but most are nowhere near accurate.

I usually give an estimate on age such as 5-7 years, 10-12 years etc. I will tell the buyers that there's not a date on a roof like a water heater or heating and air units so it's just an estimate. Most of the time I'm pretty accurate, but tell them if I was wrong it wouldn't be the first time.

[Steven Hockstein]

Roof cover age is often disclosed if the seller has been an occupant. Just as with gardening where every location is a local climate, every roof faces its own challenges to its guard duty for the building.

I just do the best I can to describe what I see.

The "sellers disclosures" around here are hardly worth the paper they're written on and often seem like an outright lie. I'm sure some try and truthfully fill theirs out, but most are nowhere near accurate.

I usually give an estimate on age such as 5-7 years, 10-12 years etc. I will tell the buyers that there's not a date on a roof like a water heater or heating and air units so it's just an estimate. Most of the time I'm pretty accurate, but tell them if I was wrong it wouldn't be the first time.

How about just stating the condition, especially if you are letting them know that your estimate of the age can be wrong (AKA meaningless)?

I just let them know the current condition and if it needs to be repaired or replaced. If the roof is in bad condition but not currently leaking I warn them that they should budget for replacement in the very near future. I recommend that they get an estimate for the cost of replacement. That is all they want and need to know unless there is a warranty issue.

[palmettoinspect]

Roof cover age is often disclosed if the seller has been an occupant. Just as with gardening where every location is a local climate, every roof faces its own challenges to its guard duty for the building.

I just do the best I can to describe what I see.

The "sellers disclosures" around here are hardly worth the paper they're written on and often seem like an outright lie. I'm sure some try and truthfully fill theirs out, but most are nowhere near accurate.

I usually give an estimate on age such as 5-7 years, 10-12 years etc. I will tell the buyers that there's not a date on a roof like a water heater or heating and air units so it's just an estimate. Most of the time I'm pretty accurate, but tell them if I was wrong it wouldn't be the first time.

How about just stating the condition, especially if you are letting them know that your estimate of the age can be wrong (AKA meaningless)?

I just let them know the current condition and if it needs to be repaired or replaced. If the roof is in bad condition but not currently leaking I warn them that they should budget for replacement in the very near future. I recommend that they get an estimate for the cost of replacement. That is all they want and need to know unless there is a warranty issue.

I also note the condition, not just the age. It's really not that hard give an accurate age of a roof.

[Marc]

I also note the condition, not just the age. It's really not that hard give an accurate age of a roof.

Now you've got me confused.

I usually give an estimate on age such as 5-7 years, 10-12 years etc. I will tell the buyers that there's not a date on a roof like a water heater or heating and air units so it's just an estimate. Most of the time I'm pretty accurate, but tell them if I was wrong it wouldn't be the first time.

Marc

[palmettoinspect]

I also note the condition, not just the age. It's really not that hard give an accurate age of a roof.

Now you've got me confused.

I usually give an estimate on age such as 5-7 years, 10-12 years etc. I will tell the buyers that there's not a date on a roof like a water heater or heating and air units so it's just an estimate. Most of the time I'm pretty accurate, but tell them if I was wrong it wouldn't be the first time.

Marc

Sorry, should've been a little more clear. The "just an estimate" is referring to the age.

[John Dirks Jr]

I don't try and guess the age. I do give an estimated remaining life based on the condition of the shingles. My range of estimations are as such and include the descriptive characteristics that gave me the conclusion;

1) The roof covering is at or beyond its service live and needs to be replaced.

2) The roof covering is approaching the end of its service life and will need to be replaced within the next 2-3 years.

3) The roof covering is in satisfactory condition and should last at least 5 years (provided that its not subjected to physical damage)

And so on.

Of course, these estimates are only part of the reporting. I also put in the various repair and installation concerns that are found. And they can be found on any roof, regardless of the remaining life of the covering.

[Mundo Inspector]

The list of things that affect shingle lifespan:

Shingle Quality

Low-quality shingles will fail before high-quality shingles. Quality can vary widely among manufacturers, and even within a single manufacturer?s product line.

Structure Orientation

South-facing roof slopes have shorter lifespans due to increased thermal cycling and UV exposure. Some portions of the roof are affected by prevailing winds more than others.

Degree of Roof Slope

Flatter roofs have shorter lifespans because they shed moisture more slowly and are more directly exposed to UV radiation than roofs with steeper pitches.

Climate

Harsh climates shorten roof lifespans. Wind, moisture and thermal cycling all contribute to deterioration of roofing materials.

Thermal Cycling

Climates with large daily temperature swings shorten roof lifespans because they cause greater amounts of expansion and contraction. This increases the roof's rate of deterioration.

Roof Color

Darker roofs absorb more heat, which shortens shingle lifespan by accelerating the loss of volatiles and increasing thermal cycling.

Elevation

Homes at higher elevations are exposed to more UV radiation, which deteriorates most roof-covering materials, including asphalt shingles.

Roof Structure Ventilation

Poor ventilation of the roof structure shortens shingle lifespan by failing to keep shingles cool, resulting in accelerated loss of volatiles and greater amounts of thermal cycling.

Quality of Maintenance

Failure to repair damage and keep roofs clean can result in damage and deterioration from moisture intrusion and wind.

Identical shingles models will have different lifespans in different climate zones and different shingles models will have different lifespans in the same climate zones. If you've been a roofing contractor for many years in one area, then maybe you can accurately identify and estimate the age of a particular shingle model, but for most inspectors, it's not necessary, and it's a liability. Just state the condition and identify deficiencies.

[Mundo Inspector]

Say it has 15 to 20 year shingles on a sloped gable roof.

If you have an exact date the house was built, like 1972, then you know the house is 43 years old and the roof you're looking at is either the old second roof or the 3rd roof.

If the roof is multiple layers, I count about 25 yrs for Cedar shingles and 15 years for each layer of asphalts. Tear it all off.

Newer house, how old is the house? Easy one. []

Unless the roof was trashed by hail and replaced at some point, which makes the date of original construction moot as far as shingle age. Dont' try to give shingle age.

[Mundo Inspector]

Everyone thinks shingles are the most important part of a roof and that they last 20 years. Not so.

That's right and wrong. Shingles are the most important part of a shingle roof (as far as the roof covering material goes), but not everyone thinks all shingles have a 20-year warranty or last 20 years. Good ones last longer, cheap ones may not last that long.