How to Find 20-Year-Old Roofs in Your Area (A Roofer's Field Playbook)

Every roofer has stood in a truck on a residential street and felt the same dumb math. There are forty houses on the block. Most of them have a roof that is fine. A handful are quietly rotting under shingles that look passable from the curb. And you have no idea which is which until you knock all forty and burn a Saturday finding out.

Finding 20-year-old roofs in your area is the whole game, because a roof that is two decades old is a roof that is either due now or due soon. Architectural asphalt shingles, the gray and brown three-tabs and laminates on most American houses, get sold with 25- and 30-year labels, but the field life is shorter than the label almost everywhere that gets real sun, heat cycling, or hail. So a 20-year-old roof is your sweet spot: old enough that the homeowner is starting to notice granules in the gutter, young enough that they have not already replaced it.

The problem is that roof age is invisible. Nobody puts it on a sign in the yard. The public records that everyone reaches for first tell you when the house was built, not when the roof was last torn off. So the question is not really 'where are the old houses' — it is 'where are the old roofs,' and those two questions have very different answers.

What follows is the actual workflow practitioners use to answer that second question: the data sources that work, the ones that lie to you, how to read a roof's age off an aerial photo with your own eyes, how to rank a street so you knock the right twelve doors instead of all forty, and the mistakes that quietly waste a season of gas and stamps. There are worked examples, checklists, and numbers you can plug into your own market.

Why a 20-year-old roof is the number you actually want

Before you go hunting, it helps to know exactly why 20 years is the target and not 15 or 30. The answer is about replacement probability and homeowner psychology, more than it is about the shingle warranty.

The label lies, the field is shorter

Manufacturers print '30-year' or 'lifetime' on the wrapper, but those numbers describe a prorated material warranty under ideal conditions, not the years the roof will keep a house dry. The National Roofing Contractors Association has long pushed homeowners and contractors away from treating the printed warranty as a service-life estimate, because installation quality, ventilation, slope, color, and climate move the real number around a lot.

In practice, here is the spread most experienced crews see on standard architectural asphalt:

Notice that across every row, the 18-to-22-year band is where the roof crosses from 'still has time' into 'replacement is now a live question.' That is why 20 is the anchor. A 20-year-old roof in Phoenix or Dallas is often past due. A 20-year-old roof in coastal Oregon might have a few good years left. Same age, different urgency — and that nuance matters when you build a target list, because age alone is necessary but not sufficient.

The buying window opens around year 18

There is a behavioral reason too. Homeowners do not call a roofer the day the warranty expires. They call when something prompts them: a leak stain on the ceiling, a neighbor's new roof going on, granules washing out of the downspout, an insurance non-renewal letter, or a real-estate agent telling them the roof will tank the sale. Those prompts cluster in the late teens and early twenties of a roof's life. A roof at 20 is in the zone where prompts are landing and the homeowner is mentally pre-qualified — they half-expect the conversation. A roof at 8 years is a wasted knock; a roof at 35 has usually already been replaced or is owned by someone who will never spend the money.

Old roof beats 'nice neighborhood'

A lot of contractors target by income or by zip-code prestige. That is a weak proxy. A wealthy subdivision built in 2015 has nine-year-old roofs and nothing to sell. A working-class neighborhood built in 1999 has a street full of roofs in their early twenties and homeowners who genuinely need the work. Roof age outperforms neighborhood prestige as a targeting signal almost every time, because you are selling a replacement, and replacement demand is a function of age and condition, not of how new the cars in the driveway are.

What 20 years is worth to your business

It helps to put a dollar frame on why this targeting work pays. A residential reroof is typically a four- to low-five-figure job depending on roof size, pitch, material, and your market. That means a single converted door is worth more than most contractors spend on a month of mail. Run the math the other way and the discipline becomes obvious: if knocking a poorly-targeted street of forty doors yields one inspection and a 1-in-5 close, you spent a crew-half-day for a fifth of a job. Knock a pre-vetted street where most doors are genuinely old and the same half-day can yield three or four inspections. You did not work harder; you worked a better list. The entire return on every method here is the gap between those two outcomes, and on a job that size, even a small lift in list quality compounds fast across a season.

The two failure modes of an untargeted list

There are exactly two ways a roof-age list can be wrong, and they cost you differently. A false positive is a roof you target that turns out to be new — you waste a knock or a stamp, which is annoying but cheap. A false negative is an old roof you never targeted because your method missed it — that is a job a competitor gets instead, which is expensive. Most contractors obsess over false positives (wasted effort) and ignore false negatives (lost jobs), but the lost jobs are the bigger number. Good targeting trims both, but if you have to err, err toward casting a slightly wider net on genuinely old-looking roofs rather than missing them.

The data sources, ranked by how much they actually help

There is a hierarchy of information for finding old roofs, and most roofers start at the wrong end of it. Here is each source, what it really tells you, and where it quietly misleads you.

Tier 3: Year built (Zillow, county assessor, Realtor sites) — the trap everyone falls into

The instinct is to pull up Zillow or the county assessor's parcel viewer, filter by 'year built,' and call any house from 20-plus years ago an old roof. This is the single most common mistake, and it is worth understanding exactly why it fails.

Year built tells you the age of the structure. It tells you nothing about the age of the roof. A house built in 1998 has been around 27 years — but if the roof was torn off and replaced in 2016 after a hailstorm, that roof is nine years old and you are about to waste a knock. Re-roofs are invisible to the assessor in most counties, because a like-for-like reroof either needs a minor permit that never gets recorded against the parcel's 'year built' field, or it gets done with no pulled permit at all, which is extremely common on residential tear-offs.

So year built systematically overcounts old roofs. In a neighborhood built in 2000, a meaningful share of the homes have already been reroofed once. If you door-knock the whole subdivision on the theory that 'these are all 25-year-old houses,' you will knock a lot of nine-year-old roofs and your close rate will tank for reasons you cannot see.

That said, year built is not useless. It is a fine first filter to find candidate neighborhoods — entire subdivisions with a build year in the late 1990s or early 2000s are worth investigating. Just never treat it as roof age, and never knock a list built only on year built. Use it to pick the block, not the door.

Tier 2: Permit records — slow, partial, but real

Most cities and counties keep a searchable permit database. A reroof permit, where it exists, is a near-direct timestamp on the roof: if a permit for 'reroof' or 'roof replacement' was pulled at 123 Main St in 2014, that roof is about 11 years old, full stop.

The value here is inverted from what you would expect. You are not looking for houses that have a reroof permit — you are using permits to cross off the houses that do, so you stop knocking roofs that were recently replaced. Permit data is best used as a subtraction filter.

The limitations are real:

• Coverage is wildly uneven. Some jurisdictions log everything; some barely log residential reroofs at all.
• Permit-skipping is rampant. A large fraction of residential tear-offs in many markets happen with no permit pulled, so the absence of a permit does not prove the roof is original.
• The data is clunky to pull at scale. You are often searching one address at a time on a 2009-era government web portal.

So permits help you remove known-recent roofs from your list, but they cannot build the list for you and they cannot be trusted to be complete.

Tier 1: Aerial and satellite imagery — where roof age actually lives

The roof itself is the most honest source, and you can see it from above. Aerial imagery — Google Earth, the satellite layer in your mapping app, county GIS orthophotos, and historical aerial archives — lets you look at the actual surface of the roof and read its condition and, with the historical layer, its age.

This is the source that separates roofers who waste their week from roofers who do not, because the roof in the photo cannot lie about a reroof. If a roof was replaced in 2016, the 2014 historical aerial shows the old roof and the 2018 aerial shows the new one, and the difference is visible. More on how to actually read these photos in the next section, because this is a learnable skill.

The catch is that reading aerials at scale is slow and tiring. Eyeballing one roof takes thirty seconds; eyeballing every roof in a 4,000-home territory is a job nobody finishes. That scale problem is exactly where the modern tooling comes in, and we will get to it.

Where it all nets out

The honest summary: year built finds you neighborhoods, permits subtract recently-replaced roofs, and aerial imagery is the only widely available source that shows the roof itself. The pros who are good at this combine all three — and the slow part, every time, is looking at enough roofs.

How to read a roof's age off an aerial photo with your own eyes

This is a genuine skill, and it is worth building even if you later automate it, because it teaches you what 'old' looks like. Open Google Earth Pro (free on desktop, and it has a history slider, which the browser version mostly lacks) and pick a street you already know. Here is what to look at.

Color and tone: the fade tells the age

A new asphalt roof is dark and saturated — deep charcoal, rich brown, uniform. As a roof ages, the protective granules wear off and the asphalt mat underneath starts to show, so the surface lightens, goes gray, and loses contrast. An old roof reads pale, washed-out, and flat in the photo compared to its newer neighbors.

The single most useful trick: compare a roof to the others on the same street, shot in the same image on the same day under the same light. If four roofs are dark and one is noticeably gray and chalky, that gray one is your old roof. Relative tone within one image is far more reliable than trying to judge a roof in isolation, because it cancels out the lighting and camera differences.

Streaking and biological growth

The dark streaks running down many roofs are algae (Gloeocapsa magma), and they take years to establish and spread. Heavy, dark vertical streaking is a strong tell of an older, weathered roof. Moss buildup, especially in damp and shaded climates, packs into the keyways and the north slopes and signals a roof that has been sitting long enough to grow a garden. Neither is a perfect timestamp, but a heavily streaked, moss-flecked roof is rarely young.

Surface texture and granule loss

Zoom in. A healthy roof has an even, slightly pebbled texture from intact granules. An old roof shows mottling, blotches, shiny patches where the asphalt is exposed, and uneven coloring across the field. On the highest-resolution county GIS orthophotos you can sometimes see individual worn courses and the difference between a north and south slope, where the sun-facing south side has aged faster.

Patches, mismatched planes, and prior repairs

A section of roof that is a different color from the rest means a partial replacement or repair. Mismatched planes tell a story: somebody fixed a leak, or reroofed one wing of the house. These are nuance signals — a patched roof can still be old overall, but it tells you the homeowner has already had roof problems, which is a buying signal in itself.

The history slider: the closest thing to a roof's birthday

This is the move most contractors never learn. In Google Earth Pro, click the clock icon and a timeline of historical aerials appears, often going back fifteen or twenty years depending on the area. Now you can do something powerful: scrub backward in time and watch for the moment a roof changes color.

Worked example. You are looking at 412 Oak Lane. In the current 2025 image the roof is medium-gray, plausibly old. You drag the slider back. In 2019 it looks the same gray. In 2015 it suddenly goes dark charcoal — and the 2014 image is also dark. That jump from a 2015 dark roof to a still-gray 2019 roof means nothing was replaced; that roof has been weathering since at least 2014 and is likely original to an older house. Now scrub a different house, 418 Oak Lane: in 2025 it is dark and clean, but in 2013 it was pale and streaky, and somewhere between 2013 and 2016 it jumps from pale to dark. That jump is a reroof. 418 was replaced around 2015 and is a ten-year-old roof — cross it off.

That single technique, watching for the color jump in historical imagery, is how you separate a genuinely old original roof from a house that merely looks old by year built. It is slow done by hand, but it is the most accurate manual method available, and an hour of practicing it on streets you already know the answers to will calibrate your eye permanently.

A manual aerial read, start to finish

Put it together as a repeatable routine for vetting one address:

1. Open the address in Google Earth Pro, zoom to roof level.
2. Judge current tone relative to neighbors — dark, medium, or pale/gray.
3. Check for streaking, moss, mottling, and patches.
4. Open the history slider and scrub back as far as it goes.
5. Look for a color jump (pale-to-dark = reroof; consistently dark-then-fading = original aging roof).
6. Cross-check year built and any reroof permit to confirm.
7. Tag the roof: NEW (skip), AGING (watch), or OLD/DUE (knock).

Do this on twenty houses and you will feel how slow it is at scale — which is the whole reason the next sections exist.

Edge cases that fool the aerial read

The method above is reliable on standard asphalt shingle in average light, but a few situations will trip you up, and knowing them keeps you from making confident wrong calls.

• Light-colored shingles. A roof installed in a tan, weathered-wood, or light-gray blend reads pale even when new. Do not call it old on tone alone; lean harder on the history-slider color jump and on streaking, which a genuinely new light roof will not have.
• Metal, tile, and slate. These do not fade like asphalt and can be decades old while looking fine from above. Age-by-fade only works on asphalt. For these materials, the history slider (did it get replaced) and known service life matter more than tone.
• Heavy tree cover. Mature trees over a roof both shade it (slowing fade, making it look younger) and drop debris and organic matter (speeding moss and streaking, making it look older). Shaded roofs are genuinely hard to read; flag them as 'inspect on the ground' rather than forcing a call.
• Stale imagery. The 'current' aerial in your app might be two or three years old. A roof that looks 18 in the photo is really 20 or 21 today. Check the image date if your tool shows it, and add the lag to your age estimate.
• Recent partial repairs. A bright patch on an otherwise faded roof is a repair, not a reroof — the overall roof is still old, and a homeowner who paid for a patch recently is a warm prospect because they already know the roof is failing.

None of these break the method; they just tell you when to downgrade your confidence and let the ground inspection be the tiebreaker.

Do a calibration pass before you trust your own eye on strangers' roofs: pick ten houses you have personally been on or reroofed, and read them blind in the aerial first, then check your call against what you actually know. You will quickly learn your own biases — most people over-call light roofs as old and under-call shaded ones. Adjust, and your hit rate climbs.

Turning a city into a target list: the manual workflow

If you are doing this without specialized tooling, here is the end-to-end process that works. It is labor-intensive but it is real, and plenty of successful contractors run exactly this.

Step 1: Pick candidate neighborhoods by build era

Start wide. Use the county assessor's GIS parcel viewer or a real-estate site to find subdivisions with a dominant build year between roughly 1998 and 2006. Those are your richest hunting grounds today: a 1999-built tract has roofs that, if original, are now 26 years old (already due, many already replaced) and a 2004-built tract has roofs around 21 years old — closer to the sweet spot, with fewer of them already reroofed.

Sweet-spot logic by build year, working from today:

The 2003-to-2007 band is usually the best ratio of 'old enough to need it' to 'not yet replaced.' Mark three or four of those subdivisions on a map.

Step 2: Aerial-scan each candidate street

Now go street by street in Google Earth, applying the manual read from the previous section. You are sorting every roof into NEW, AGING, or OLD/DUE. This is the slow part. Realistically you can carefully vet maybe 60 to 100 roofs an hour once your eye is trained, which means a 2,000-home set of subdivisions is twenty to thirty hours of screen time. That is the honest cost of doing it purely by hand.

Step 3: Subtract the recently-permitted reroofs

For your OLD/DUE candidates, spot-check the city permit portal for any reroof permit in the last ten years. Where a recent permit exists and the aerial is ambiguous, trust the permit and drop the address. This catches reroofs that your eye might have missed, especially on roofs replaced like-for-like in the same shingle color.

Step 4: Build the route

Group your surviving OLD/DUE addresses by physical proximity so a canvasser walks a tight cluster instead of crisscrossing. A good day's knock route is a connected set of 60 to 120 doors where most of them are pre-qualified as old. Compare that to the default of knocking forty random doors per street and you can see the leverage: same number of knocks, far higher hit rate.

Step 5: Track and recycle

Log every door in a CRM or even a spreadsheet with the roof tag, the date knocked, and the outcome. The AGING roofs you tagged but did not knock this year are next year's list — a roof you flagged as 17 years old is a 19-year-old roof in two seasons, and a warm callback. This is the part most contractors skip, and it is free pipeline.

The honest cost of the manual method

Done well, the manual workflow produces a genuinely good list. The problem is purely throughput: it does not scale past one diligent person with a lot of patience, and the eyeball read, while learnable, is subjective and gets tired. If you are a one- or two-crew shop, the manual method is completely viable for a season. If you are trying to feed multiple crews across a metro, the hours stop adding up, and that is the moment to look at tooling.

Where automated roof-age data fits — and what it can and cannot do

Everything above is doable by hand. The reason a tooling category exists is that the slow, tiring part — looking at every roof in a large area and judging its age and condition — is exactly the kind of task that scales badly for humans and well for software trained to read aerial imagery.

This is the lane RoofPredict works in. The short version of what it does: it scans the aerial imagery across an area you choose and gives you, house by house, an estimated roof-age range plus a model of the storms that roof has actually taken — so instead of squinting at the history slider on 2,000 homes, you get a ranked list of which roofs are old enough to be due. It is the manual aerial read from earlier, run at metro scale and paired with weather.

A few honest specifics, because overselling this category is how roofers get burned by software subscriptions and learn to distrust the whole idea.

Roof age is a range, not a birthday

No aerial tool, and no human looking at the same photo, can tell you a roof was installed on a specific date. What you get is a range — for example, '18 to 22 years' — derived from how the roof has weathered and how it has changed across historical imagery. That range is exactly what you need for targeting (it tells you a roof is in the due band) but it is not a certificate of installation. Anyone promising an exact install date from a satellite photo is selling you something that does not exist. A tight range is the honest, useful output, and it is the same thing your trained eye produces, just faster and across every house.

Storm modeling is odds, not proof

The weather side is where this gets more useful than a plain age estimate. A hail map shows you where it hailed — a big colored blob over half a county. That is nearly useless at the address level, because hail falls unevenly and a roof at the edge of the swath might be untouched while one in the core is hammered. Modeling the storm on each individual roof — accounting for where the roof sits relative to the storm's track, its slope, its orientation — gets you closer to which specific roofs were likely worn out versus merely rained on.

The honest limit: this is probability, not a damage report. The model says a given roof had high odds of taking meaningful impact. It does not prove damage, and it is not a substitute for an inspection. Your crew still gets on the roof, still documents what is actually up there. The model's job is to tell you which roofs are worth the climb, not to climb for you.

What it does not do, on purpose

It does not buy you leads — there is no shared homeowner being resold to five competitors. It does not measure the roof for an estimate; that is a different category of tool entirely, the EagleView and HOVER lane, which gives you precise measurements but says nothing about how old or worn the roof is. And it stays entirely out of the insurance claim: it can hand you and the homeowner documentation of roof age and storm history that supports a storm-damage discussion, but the inspection, the claim, and the coverage decision stay between the homeowner, their carrier, and the adjuster. A roofer documents conditions and writes an estimate; the insurer decides coverage; the homeowner owns the claim. Anyone in this business needs to keep those lanes clean.

When the tooling earns its keep, and when it does not

If you are one crew working neighborhoods you already know cold, the manual method is fine and you may not need anything. The tooling earns its keep when the area is bigger than you can eyeball, when you are feeding multiple crews or a mail program that needs thousands of vetted addresses, or when you want the weather layer fused with age so you are not running two separate vendors and stapling their outputs together by hand. The right way to evaluate it is the same way you would evaluate a new estimator: hand it a street you already know the answers to, and see if it tells you what you already know.

A simple test before you trust any roof-age tool

Do not take a vendor's word, and do not take a homeowner's word either. Run a blind check. Pick a street where you have firsthand knowledge — roofs you have reroofed, inspected, or know the history of — and have the tool rank it without telling it the answers. Then compare. The roofs you know are new should land at the bottom; the ones you know are due should rise to the top. If it nails the ones you can verify, it has earned a little trust on the ones you cannot. If it calls your own recent reroof a 20-year roof, you have learned something important before spending a dime on a list. This same blind-street test works for grading your own eye, a mailing-list vendor, or any data source that claims to know which roofs are old — make it prove it on ground you already own.

The weather layer deserves the same scrutiny. If a tool tells you a roof took a modeled hit, cross-check it against the public storm record for that date and location — the National Weather Service and the Storm Prediction Center publish storm reports you can look up for free. If the model claims a roof was hammered on a day with no severe weather anywhere near it, that tells you something. Holding the tool to public ground truth is how you separate a model worth using from a colored map dressed up as analysis.

Matching the method to how you actually sell

Finding old roofs is the input. How you turn that into work depends on your sales motion, and the targeting tightens differently for each.

If you knock doors

Your constraint is canvasser hours and morale. A green canvasser who knocks forty random doors and gets brushed off all day quits in three weeks. The same canvasser knocking a pre-vetted route of old roofs gets real conversations, books inspections, makes money, and stays. Targeting is more than a close-rate lever; it is a retention lever, because nothing burns out a new rep faster than a list with no juice in it.

Give the canvasser a per-door talking point tied to the roof. 'I was looking at the roofs on this street and yours looks like it's in the 20-year range — when did you last have it looked at?' is a wildly better opener than 'we're doing roofs in the neighborhood.' The first one is specific and earns a beat of attention; the second one is noise.

If you mail

Mail punishes you for every wrong address. At current postage and print, a targeted mail piece runs you real money per household, and your response rate on a roofing offer is low single digits at best. The entire economics of a mail program live or die on list quality. Mailing a list filtered to genuinely old roofs versus a list filtered only on year built is the difference between a campaign that pays for itself and one that quietly loses money on every drop, and you often cannot tell which you are running until the responses (or the silence) come back. Tighten the list before you ever pay the printer.

If you sit on a CRM full of old estimates

This one is found money. Every roofer has a book of old estimates and past customers — homeowners you bid four, six, eight years ago who did not buy then. A roof you inspected eight years ago and called 'a few years left' is now a roof that is due. Those people already know you, already let you on their roof once, and have aged into the buying window. Mining your own book by roof age is the cheapest pipeline you own, and it does not smell like a rented lead to the homeowner because you have a real prior relationship. Run your old database against roof age and call the ones that have crossed into the due band.

If you do storm restoration

Your edge is matching age to storm. A 19-year-old roof that just took a modeled direct hit from hail is a far stronger door than a five-year-old roof in the same swath, because the older roof has less margin and the conversation about replacement versus repair is more credible. The hail map alone, the county-sized blob, sends you and every out-of-town crew to the same streets. Layering roof age on top of per-roof storm modeling tells you which roofs in the swath were already vulnerable and got hit — a much sharper list than 'everywhere it hailed.'

A legal note that matters here: document what is on the roof, write your estimate, and let the homeowner and their carrier handle the claim. Do not present a storm model or a hail map as proof of damage, do not position yourself as a claims handler or adjuster, and stay entirely away from anything to do with the homeowner's deductible. The age-and-storm documentation supports the homeowner's conversation with their insurer; it does not replace an inspection and it does not decide coverage.

What pros get wrong

A few mistakes show up over and over, even among experienced operators.

Mistaking year built for roof age

We covered it above, but it is the number-one error so it earns repeating: a list built only on year built is full of reroofs you cannot see, and it silently drags your numbers down. Always get the roof itself into the loop, by eye or by tool, before you spend money knocking or mailing the list.

Targeting prestige instead of age

The nicest subdivision in town might be the worst target because it is new. Chase roof age, not the income of the neighborhood. The work is where the old roofs are, and old roofs do not care what the cars in the driveway cost.

Judging a roof in isolation

A roof that looks 'kind of gray' on its own might be perfectly normal for that shingle color and that light. Always judge relative to the neighbors in the same image. Relative tone is the reliable signal; absolute tone fools you constantly.

Skipping the history slider

Contractors who only look at the current aerial cannot distinguish an original old roof from a recent reroof, and they knock both. The historical color-jump check is the single technique that fixes this, and almost nobody does it by hand because it is tedious. If you are going by eye, do not skip it.

Treating storm probability as proof

A modeled storm hit means the roof had high odds of damage. It does not mean there is damage, and it is not something to wave at a homeowner or anyone else as evidence. Get on the roof and document what is actually there. The model points the crew; the crew finds the facts.

Not recycling the aging list

The roofs you tag as 16 or 17 years old today are your warmest list in two or three years. Throwing that work away because they did not buy this season is leaving money on the table. Log them and come back.

Buying it once and never refreshing

Roof age is a moving target. The list you built two years ago has aged two years — some of those AGING roofs are now DUE, and some of your DUE roofs have been replaced (by you or a competitor) and should come off. Whatever method you use, the list is a living thing, not a one-time pull.

A 30-day plan to stand this up

If you are starting from zero, here is a concrete sequence that turns the ideas above into a working pipeline inside a month.

Week 1 — Map the ground. Pull your county GIS parcel viewer. Identify and mark four to six subdivisions with a dominant build year in the 1998-to-2007 range. Rank them by the build-year table above, favoring the 2003-to-2007 band for the best ratio of due-but-not-yet-replaced. Pick the top three to work first.

Week 2 — Train your eye. Spend a few hours in Google Earth Pro on streets you already know. Practice the relative-tone read and the history-slider color-jump check until you can call NEW vs OLD/DUE quickly and confidently. Validate against any roofs you have personally been on, so you calibrate against ground truth.

Week 3 — Build the first list. Aerial-scan your top subdivision, tagging every roof NEW / AGING / OLD/DUE. Spot-check your OLD/DUE addresses against the permit portal to subtract recent reroofs. Decide here, honestly, whether the hours are sustainable for the area size you are working — if not, this is the point to evaluate a roof-age data tool against a street you already know, the same way you would test any new vendor: see if it agrees with your trained eye before you trust it on streets you do not.

Week 4 — Work it and instrument it. Route your OLD/DUE addresses into tight knock clusters or a tight mail drop. Run your existing CRM of old estimates against the due band and call the ones that have aged in. Log every door and outcome, and park the AGING roofs as next season's callback list. By the end of the month you have a vetted, recyclable pipeline built on roof age instead of guesswork.

Quick-reference checklist

Use this before you knock or mail anything.

• Candidate neighborhoods chosen by build era (favor 2003 to 2007 originals), not by prestige.
• Every target roof judged by the roof itself — aerial read or tool — not by year built alone.
• Relative tone compared to neighbors in the same image, not judged in isolation.
• History slider checked for the reroof color-jump on anything ambiguous.
• Recent reroof permits subtracted from the OLD/DUE list.
• Roof age treated as a range, never a precise install date.
• Storm hits treated as odds that point the crew, never as proof of damage.
• Claims lane kept clean — document and estimate, let the homeowner and carrier handle coverage.
• AGING roofs logged as next season's callback list.
• List refreshed on a schedule, because every roof is aging while you read this.

Finding 20-year-old roofs is not about a secret database. It is about looking at the roof instead of the parcel record, knowing what old looks like from above, subtracting the reroofs you cannot see by eye, and then knocking the doors that are actually due instead of the whole street. Do that by hand if your area is small, lean on tooling when it gets too big to eyeball, and either way you stop spending gas, stamps, and your crew's patience on roofs that were replaced years ago — and start spending them on the homeowners who genuinely need you now.

FAQ

Can I tell how old a roof is just from Google Maps or Zillow?

Zillow and the county assessor give you the year the house was built, which is not the roof's age — re-roofs are usually invisible to those records. Google Maps' satellite layer is better because you can see the roof itself, but the real tool is Google Earth Pro's history slider, which lets you scrub through years of aerial photos and spot the moment a roof's color jumps from pale to dark, signaling a replacement. Current imagery alone tells you condition; the historical slider is what reveals age.

Why is a 20-year-old roof the right target instead of 25 or 30?

Most architectural asphalt shingles have a real-world service life shorter than their printed warranty — often 18 to 25 years in average climates and less in high-heat or hail-prone areas. Around year 18 to 20, homeowners start getting the prompts that make them call a roofer: granules in the gutter, a neighbor's new roof, an insurance letter. A 20-year-old roof is old enough to be a live replacement question but young enough that it usually has not already been replaced, which is the best ratio for sales.

How do I read a roof's age off an aerial photo?

Judge the roof's tone relative to its neighbors in the same image: new asphalt is dark and saturated, while old roofs fade to pale gray as granules wear off. Look for dark algae streaking, moss, mottling, and patches, all of which take years to develop. Then open the history slider in Google Earth Pro and scrub backward — a roof that stays dark in old photos then fades is an original aging roof, while a roof that jumps from pale to dark has been replaced. Practice on streets you already know to calibrate your eye.

What is the biggest mistake roofers make when targeting old roofs?

Building a target list from year built alone. A neighborhood built in 2000 has plenty of homes that were already re-roofed after a storm, and those reroofs do not show up in assessor records. If you knock or mail the whole subdivision on the theory that they are all 25-year-old houses, you will hit a lot of recently replaced roofs and your numbers will quietly suffer. Always get the roof itself into the loop — by eye or by tool — before spending money on the list.

Do permit records help me find old roofs?

Yes, but as a subtraction filter, not a primary source. A reroof permit timestamps a recent replacement, so you use permit data to remove recently-replaced roofs from your list rather than to find old ones. The limits are real: permit coverage varies a lot by jurisdiction, and a large share of residential tear-offs happen with no permit pulled, so the absence of a permit does not prove a roof is original. Use permits to confirm and subtract, never as your whole list.

How does roof-age data from aerial imagery actually work, and how accurate is it?

Tools that read aerial imagery estimate a roof's age by how it has weathered and how it has changed across years of historical photos, the same signals a trained human reads, run across every house in an area. The output is a range — for example 18 to 22 years — not an exact install date, because no satellite photo can pinpoint a specific installation day. A range is exactly what targeting needs, since it tells you which roofs are in the due band. Anyone promising an exact install date from a photo is overstating what is possible.

Is finding old roofs the same as buying roofing leads?

No. A lead service sells you a homeowner's contact information, often the same homeowner resold to several competitors. Finding old roofs by age is targeting your own outbound — you are choosing which doors to knock or mail from public addresses, with no shared homeowner being resold. The homeowner has not raised their hand; you are deciding, based on roof age, which ones are worth your time. It sharpens work you already own rather than renting you a contact.

How is roof-age targeting different from EagleView or HOVER?

They are different categories. EagleView, HOVER, and similar measurement tools tell you the precise dimensions of a specific roof so you can build an accurate estimate — they answer 'how big is this roof.' Roof-age targeting answers 'which roof should I go after,' by reading age and condition across many homes. One helps you measure a roof you have already decided to bid; the other helps you decide which roofs to pursue in the first place. Many contractors use both at different stages.

Can roof age and storm data be used for insurance claims?

Roof-age and storm-history documentation can support a homeowner's storm-damage conversation with their insurer, but it does not replace an inspection and it does not prove damage. A storm model gives odds that a roof was hit, which points your crew to which roofs to inspect — the crew still documents what is actually on the roof. The contractor documents conditions and writes an estimate; the insurer decides coverage; the homeowner owns the claim. Roofers should not position themselves as claims handlers or adjusters, present a model as proof, or get involved with the homeowner's deductible.

How often should I rebuild my list of old roofs?

Treat it as a living list, not a one-time pull. Roofs age continuously, so a roof you tagged at 16 years is in the due band a couple of seasons later, and roofs you tagged as due may get replaced by you or a competitor and should come off. A practical rhythm is to refresh your target area at least once a season, recycle the aging roofs you flagged but did not knock, and remove the ones that have visibly been re-roofed since your last pass.