Granules in your gutters or at the bottom of a downspout are usually not a problem. New shingles shed loose granules for months or years, and every roof loses some as it ages. The problem is bare, dark patches of asphalt where the colored granules are gone, because the granules are what shield the asphalt from the sun. Three makers and an inspectors' association say the same thing: loose granules are normal; exposed asphalt is the concern.
This guide helps you tell normal shedding from wear and from storm damage, and shows what each means for your warranty or an insurance claim. It cannot diagnose your roof, and it is general information, not insurance or legal advice.
What granules do
An asphalt shingle is a mat soaked in asphalt, with a top layer of mineral granules pressed into the hot asphalt. Malarkey's technical bulletin says granules protect the asphalt, the binder, from solar ultraviolet radiation and give the roof its color. IKO says the asphalt must be completely covered at manufacture to protect it from that radiation. When granules wear away in one spot until the black asphalt shows, the sun reaches material that was never meant to be exposed.
Why a new roof sheds granules
Manufacturers apply more granules than they need, so the asphalt is fully covered. IKO's bulletin says some of the extra granules are loosely held, and Malarkey's calls them "hitchhikers." Most are reclaimed at the factory, but some travel in the bundle. GAF's technical bulletin calls the same extra granules "riders" and says their loss usually is heaviest right after installation and tapers off over time.
Timing differs a little by source:
| Source | How long the early shedding lasts | Is it a defect? |
|---|---|---|
| IKO, bulletin R-2, revised August 2012 | The first few years of exposure | No; it does not shorten the shingles' weatherproofing life |
| Malarkey, technical bulletin | Often several months, up to about six months to two years depending on climate, and it continues to a lesser degree over the roof's life | No |
| GAF, bulletin TAB-R-112 | Usually heaviest right after installation and reducing gradually; GAF often recommends waiting several months | No |
| InterNACHI, hail damage part 3 | Shingles under six months old can shed a lot without the asphalt being exposed | Not functional damage |
Malarkey adds a practical point: granules in your gutters may not come from the new roof at all. If a roof was replaced but the gutters were not, the granules may be left from the old one.
Normal wear on an older roof
Granule loss continues as shingles weather. Malarkey says daily heating and cooling cycles cause granule loss at times through the shingle's life and that this is no cause for undue alarm. InterNACHI adds that as asphalt ages and loses its volatiles, its bond with the granules weakens, so an older shingle gives them up more easily. Rain and runoff also carry loose granules away.
Wear usually looks even. The whole roof, or a whole slope, looks a little thinner and a little lighter. It is more of a concern on an old roof than a young one, and it is one of the signs in our guide to when you need a new roof.
When it is more than normal
Both makers name the same situations that go beyond normal:
- Bare spots of exposed asphalt. IKO says granule loss only becomes a concern for performance when bare spots appear. GAF asks you to call its warranty service if the loss is still significant after several months, if the roof is changing color or if you see other damage.
- Severe weather. Malarkey says high winds, hail, ice dams and even inadequate ventilation can cause significant granule loss, and it recommends a professional inspection after extreme weather.
- A heavy wash after a storm. Our guide to hail damage on roofs says a heavy wash of fresh granules at the downspouts after a storm is a reason to have the roof looked at.
Normal, worn or hail
| Sign | Points to |
|---|---|
| A thin scatter of granules in the gutters on a roof under about two years old, no bare spots | Early shedding of loose granules |
| Even thinning and color fade across slopes on an older roof | Age and weathering |
| Dark, roughly round spots where granules are gone, scattered at random, with dented soft metal nearby | Hail; see hail damage vs blistering for the difference between a blister and a hail mark |
| Bare patches in a roof of any age with no storm | A defect, an installation fault or a ventilation problem; get an inspection |
| Large amounts of fresh granules after one storm | Storm damage |
InterNACHI says granule loss counts as functional damage only when it is visible to a casual observer: a few missing granules do not qualify, and if you have to squint to tell whether a mark is from hail, it is not severe enough. Small hail can also add up. IBHS, the insurance industry's research institute, found that hail under 1 inch across knocks off protective granules, and that shingles which had weathered and then taken small hail were up to ten times more susceptible to damage from a later, larger hailstorm than new shingles. IBHS says a roof's age and small-hail history matter, not only the big storms. Our guide to impact-resistant shingles covers the products built to resist hail.
What it means for your warranty
Warranties cover defects, not wear or storms. GAF's bulletin says its warranty covers manufacturing defects, and does not cover shading or visual changes from light to moderate granule loss. If the loss is severe and caused by a manufacturing defect, the warranty may apply. Malarkey asks owners to contact its warranty department if bare asphalt shows with no unusual weather.
So the order matters:
- Photograph the roof, the gutters and the downspout outlets, with the date.
- Note the roof's age, shingle line and the warranty documents.
- If the roof is new and the loss is heavy or bare spots show, contact the maker and your roofer in writing. Warranties set notice deadlines.
- If a storm came first, talk to your insurer before you repair. Our guide to roof insurance claims explains the cosmetic and functional line.
See roofing warranties for how coverage is written and what shrinks it.
Can granule loss be repaired?
Granules do not go back on. A roofer can replace shingles that are bare, and a roof with widespread loss and an old age is a replacement conversation. For a roof that is near the end, the question is when, not whether: how long a roof lasts gives ranges by material.
Frequently asked questions
How many granules in the gutter is too many?
No source gives a number. The sources agree on the test: bare, exposed asphalt on the shingles, and loss that persists or worsens after several months on a new roof.
Are granules in the gutter a sign I need a new roof?
Not alone. They matter when the roof is old, the loss is heavy and bare patches show.
Is granule loss covered by my warranty?
Only if the loss comes from a manufacturing defect. GAF says its warranty does not cover shading changes from light to moderate loss. Read your own warranty, and ask the maker to inspect.
Does granule loss mean hail damage?
Not necessarily. InterNACHI treats hail granule loss as damage only when it is plain to see. Compare with the signs in our hail guide, and have a roofer or an adjuster look.
Can I sweep the granules off or wash the roof?
Leave loose granules alone; they do no harm in the gutter. Our guide to roofing warranties notes that some makers exclude power washing, and roof moss and algae covers cleaning. Check your warranty before anyone washes the roof.
Where this information comes from
HomeAnvil does not diagnose roofs. The facts above come from published sources, read on October 13, 2026. We name no brands to buy.
- IKO, Residential Information Bulletin R-2, excess roofing granules on shingles (revised August 2012): hitchhiker granules, normal loss and when it is a concern.
- Malarkey, technical bulletin, asphalt shingles and granule sloughing (revised August 2026): purpose of granules, six months to two years, weathering and severe weather.
- GAF, TAB-R-112, granule loss on new shingles (copy hosted by InspectAPedia): rider granules, waiting several months, what to report and what the warranty covers.
- InterNACHI, Mastering Roof Inspections: asphalt composition shingles, part 46: aging, hitchhiker granules and the casual-observer test for functional damage.
- IBHS, impact testing of high concentrations of small hail: small hail, granule loss and the up-to-ten-times figure.
Related guides
How do you know if hail damaged your roof?Quarter-size (1 inch) hail can start to damage older 3-tab shingles, laminated ones at 1.25 inches. How to spot real damage and when to call your insurer.
How long does a roof last?Architectural shingles last about 30 years, 3-tab about 20, metal 40 to 80, slate 60 to 150. What shortens a roof's life, and why a warranty isn't a lifespan.
What does a roof warranty actually cover?A shingle warranty covers manufacturing defects, a contractor's warranty covers installation. How prorating, wind, algae, transfers and voiding work.
Are Class 4 impact-resistant shingles worth it?Class 4 shingles pass a 2-inch impact test under UL 2218 or FM 4473. IBHS found top-rated ones cost about 9% more per square. What the rating does not promise.
What are the signs you need a new roof?The signs a roof needs replacing, outside and in: age past 20 to 30 years for shingles, bald or curling shingles, repeat leaks, a sagging line. What each means.
Are black streaks and moss bad for your roof?Black roof streaks are algae and mostly cosmetic; moss can lift shingles. Never pressure wash. Pro cleaning costs about $300 to $1,050 for a typical roof.- What is an asphalt shingle roof, and is it right for you?Asphalt shingles are the most common home roof. 3-tab starts near $1.50 a square foot, architectural near $3.50. Life, wind, hail and warranty compared.