As a homeowner, it’s natural that you want your roof to protect your family from the elements. But the reality is that even the best roof won’t last forever, particularly if you live in a region like Texas that’s prone to hailstorms.
As your roof ages, it’s important to watch out for signs that it might be coming to the end of its life. One such sign is a phenomenon called granular loss.
In this article, we’ll explain what granular loss is, why it’s a problem, and what you can do about it. We’ll also share some other common problems that indicate your roof might be failing.
Let’s get right into it.
What Is Granular Loss?
Your roof contains hundreds of shingles: individual pieces of tile laid in rows across the roof decking to protect it from the elements.
Each shingle is coated with lots of tiny granules, usually made from minerals, crushed stone or ceramic. These granules serve multiple purposes:
- They protect the shingles from UV rays
- They improve resistance to the elements
- They make your whole home more fire-proof
- The provide some extra color and aesthetic appeal
Granular loss is when the shingles on your roof start to lose their protective granules.
To some degree, this is a normal process that’s associated with an aging roof, although it can also be accelerated by inclement weather or poor maintenance.
Whatever the cause, granular loss is something that homeowners should take seriously, as it’s one of the first signs that your roof is failing.
Signs of Granular Loss
In an ideal world, to check on your roof granules, you would climb up onto your roof and investigate the integrity of your roof shingles.
Realistically, this isn’t always possible or practical. It can be quite challenging to climb onto a roof, perhaps even dangerous if you don’t have the right equipment. It’s often easier to bring in an expert from a company like Presidio to inspect your roof professionally.
That being said, there are also some simple signs of granular loss you can look out for as a homeowner.
Piles of granules
The most obvious sign that your roof is losing granules is if you find piles of granules around your property. The two places where these are most likely to collect are:
- Your gutters
- Your downspouts
To check your gutters, put on some gloves and carefully reach inside with one hand. You’re looking for a layer of granules that’s piled up as sediment in the gutter. Check the sediment to make sure that it looks like granules, rather than leaves or twigs. If there’s a lot of sediment, consider measuring it with a ruler to see how deep it goes.
If the problem of granular loss is acute enough, you’ll also notice granules at the bottom of your downspouts. This is a sign that you’ve sustained enough damage to your granules for the granules to flow all the way through the gutter system and out at the bottom. In the worst cases, the granules will form a pile at the base of the downspouts.
Discoloration
Next, take a look at your roof as a whole. Do you see any areas that are discolored? If so, it might be a sign that your roof has started to lose some of its granules.
The discoloration associated with granular loss normally creates streaky patterns on roofs.
It might also show up as dark, round spots. This means that your roof was either missing granules and subsequently damaged in a hail storm, or the hail was so strong that it sloughed off the granules and damaged the roof at the same time.
Bald spots
Finally, look up at your shingles and see if you can see any bald spots on the roof.
By bald spot, I mean an area of the roof where there’s just the black underlayment showing, instead of the usual shingles with granules.
This means that the issue of granular loss is so severe that the shingles themselves are starting to fail and fall off your roof.
Definitely a sign that it’s time to bring in a professional to get your roof repaired!
But what was it that caused your roof to lose its granules in the first place?
What causes granular loss?
To some degree, it’s natural for your roof to lose granules over time. Precipitation, UV rays and temperature fluctuations will eventually cause the asphalt to dry out and the shingles to become brittle. This is a process that takes 15-20 years.
That being said, damage from both nature and human error can sometimes accelerate the process, as shown in the following table:
| Damage from nature | Damage from human error |
|---|---|
| The elements | Poor installation |
| Trees | Abrasive damage |
| Moss | Defective materials |
Let’s review these examples in more detail.
Damage from the elements
Storms are a major cause of damage to roof shingles, especially in Texas. For example:
- Hailstones can dislodge granules, particularly if they’re 1-inch wide or larger. Damage from hail generally appears as circular spots of granule loss.
- Wind can lift and flex shingles, loosening granules even if the shingles themselves don’t blow off. Wind-driven debris can also scrape granules off the surface.
- Repeated heavy downpours over time can erode granules, especially if the shingles are already aging or defective.
Damage from trees
It goes without saying that a tree limb that falls on your roof during a storm is likely to damage your shingles and their granules. But trees can also impact the health of your roof in more subtle ways.
The constant abrasion from low-hanging branches rubbing against the roof can scrape off granules over time. Regular trimming around your roof can help avoid this problem.
Even falling pine cones or chestnuts can be a problem, particularly if you have tall trees next to your roof. On a flat roof, these can start to accumulate if not cleaned, leading to further weakening through the growth of algae.
Moss
Moss has a tendency to grow both underneath roof shingles, as well as on top of them.
In winter, the water trapped in the moss on top of the shingles can sometimes freeze. The expansion and contraction associated with freezing and melting sometimes weakens granules, causing them to dislodge over time.
In cases where moss grows underneath shingles, it can lift them slightly, causing them to detach or lose granules.
Poor installation
Granular loss also sometimes results from human error during the roof installation process.
For example, nails driven in above the nailing strip can cause the shingle to lift and bend. If the nails are driven in too hard or too weakly, the shingles are likely to start moving and shedding granules.
If your roofing team fails to install the underlayment correctly, shingles will be subject to moisture from below, reducing granule retention. Likewise, if shingles are incorrectly aligned with each other, this can create channels for water to flow and cause premature wear and tear.
Occasionally, workmen walk on hot shingles during the installation process. This is a bad idea, since the granules will be pressed into the asphalt unevenly, loosening some areas.
Abrasive damage from workmen
Asphalt shingles aren’t designed for abrasive pressure — especially on hot days, when they’re softer. Even something as simple as dropping a tool on a roof can damage the shingles, if workmen aren’t careful.
If you’re working with chimney sweeps, satellite dish installers, or similar professionals, make sure that they don’t walk on the roof too much. Frequent abrasive contact can wear away granules.
To clean your roof, don’t be tempted into using a high-pressure water jet or bleach. While powerful and fairly cheap, these options can strip away granules, especially on older shingles where the adhesion is already weaker.
A better option is to use a soft-bristle brush together with a manufacturer-approved roof product, and then rinse it all off with some water at low pressure.
Defective materials
Lower-quality shingles typically contain:
- Less adhesive to hold granules in place
- Fewer granules per square foot, resulting in faster wear
- Less asphalt, making granules more susceptible to loosening
These features make the shingles prone to drying out, leading to premature granule loss.
By contrast, premium shingles tend to be built more robustly, with better granule adhesion. Although this means they might cost more in the short-run, you’ll often end up saving in the long-term compared to if you had bought cheaper shingles.
What are the effects of losing granules?
Remember: some granular loss is to be expected as your roof ages. So there’s no need to panic entirely!
That being said, the effects of granular loss are something that you should keep an eye on and take seriously, especially in an older property.
Here are four consequences to watch out for.
Check your paperwork
Did your granular loss occur immediately after a big storm? If so, check your insurance paperwork, because you might be able to make a claim. If you’re successful, the insurance company will pay for the cost of replacing your roof — or, at least, most of it.
It’s also worth taking a look at the warranties for both your roof materials and the workmanship provided by the installer. If it can be proven that granular loss was caused by external factors or a lack of maintenance on your side, those warranties might now be voided.
Less protection from the elements
As your granules deteriorate, your roof will become more susceptible to damage from both precipitation and the sun’s rays.
On a healthy roof, granules help water to flow off the roof structure, preventing water from pooling. With fewer granules, more water will start pooling, increasing the risks of leaks, mold and water damage.
Another role granules play is shielding shingles from harmful UV. In the absence of granules, shingles will start to dry out and deteriorate. Eventually, they will become so brittle that they start cracking, leading to leaks.
Aesthetic decline
Visually, granular loss often shows up as streaky patterns, blotches or bald spots. This gives your roof as a whole a patchy, uneven feel, which is not especially attractive to the eye.
Given that curb appeal is an important part of a property’s value, granular loss can lead to your home being valued lower if you put it up for sale. If you’re looking into selling, you’ll get a better offer if you get a new roof before talking to buyers.
Replace your roof
If your roof is 20 years old or more, and if it’s lost a large amount of granules, it’s probably a sign that you need to replace it.
Since a roof that’s lost granules is less effective at protecting your family from the elements, the investment is often worth it, especially if you plan to stay in the property for a long time.
If you have good insurance, they will often cover all or part of the cost of replacing your roof, which makes the financial side easier to bear.
Other signs your roof is failing
We said in the title of this article that granular loss is the first sign that your roof might be failing.
For the sake of completeness, here are some other signs of a failing roof that you should look out for. We’ve listed them in order of seriousness, from the least serious to the most serious.
The more of these signs you notice, the likelier it is that your roof needs replacing.
You see vegetation growing on your roof
A little bit of moss or algae growing on your roof isn’t the end of the world.
But you should be aware that plant growth will trap moisture, causing your shingles to deteriorate over time.
As a minimum, it’s a good idea to work with a professional company to keep the vegetation under control. Make sure that you use a soft wash, so as not to damage the shingles or granules with too much water pressure.
If the vegetation is widespread and your roof is on the older side, it could be time to consider replacing the roof altogether.
Your shingles are faulty
As your roof ages, its shingles will start to break down.
The first step is that the shingles start to curl, often due to water damage. As they become more brittle, the shingles then start to crack. When a shingle reaches the end of its life, it will fall off your roof altogether.
It would be premature to replace an entire roof over one curling shingle. But if shingles are missing in multiple places, it’s probably a sign that the roof needs to be replaced.
Your roof is leaking
A key warning sign that your roof might be in need of replacement is if it starts leaking. Leaks can cause mold growth, which smells nasty and might endanger the health of your family. It’s also just plain stressful to have water dripping into your property.
A word of warning, however. Not every leak means that you need to replace the whole roof. For example, it might just be that one nail has come loose, or a pipe boot has cracked.
The chances of you needing a roof replacement increase if your roof is 15 years or older, or if the roof was originally installed incorrectly.
If you’re unsure, it’s worth calling in an expert from Presidio to inspect your roof and give you some options to think over.
You found rot in your attic
Finding rot in your attic is a bad sign. It means that water has penetrated your shingles and underlayment and got through to the wooden rafters.
Worse still, if there’s rot, it likely means that the water has been collecting for a while, meaning that the problem you have is chronic.
If left unchecked, rot can compromise the structure of your roof, because it increases the weight beyond the point that the structure was designed to hold. In extreme cases, the roof could even start to sag or collapse.
At the very least, you’ll need to make some expensive repairs to the part of the roof that has rotted. If the rot is widespread, it’s a good idea to replace the roof completely.
Your roof is sagging
If you take a look at your roof from the outside, do you see it visibly sagging? Sometimes, sagging occurs all in one location, but there can also be dips in multiple places.
A roof sagging means that it likely has structural issues — the original structure is increasingly unable to bear the strain of the weight on top of it. The change in weight was probably caused by water damage, rot, or a combination of the two.
This is definitely the time to call in a professional and investigate getting a new roof before the old one caves in completely.
Wrapping up
To summarize, granular loss is normal to some degree. It occurs naturally through age and precipitation, but can also be accelerated by human error during installation and abrasion from workmen.
The more granules you lose, the more that the aesthetics and functionality of your roof will be negatively affected. If the problem becomes chronic, it might be time to replace your roof entirely. This is especially true if you find rot in your attic, or your roof is sagging.
If in doubt, it’s a good idea to bring in a professional to take a look at your roof. At Presidio, we’re happy to inspect your roof for free. Call (210) 686-6185 today to schedule an inspection.
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