How can you tell if your roof needs to be replaced? In this article, I am going to cover a bit about the aging of shingles, and how to know when you need to replace the roof due to age. I will cover storm damage to your roof in another article.
How Long Should My Roof Last?
In Southeast Texas & Southwest Louisiana, most shingle roofs will last 18-22 years, provided they have avoided being damaged by hail or wind in their lifetime, and have received proper maintenance over the years.
Fiberglass composition shingles are designed to wear at a rate of 2%-5% per year. This rate of wear is contingent on several factors, including how much rain the roof receives, the maintenance done to the roof, and even if the roof has had proper ventilation. Once a roof reaches the 12-15 year mark, repairs become more difficult to make due to the brittleness of the shingles, and the aging of the adhesive on the old shingles.
You will also notice that the new shingles do not match the original color as well. This is due to pollutants in our air. Gloeocapsa magma (AKA blue-green algae) is the most common, but when fungi combine with the algae, it becomes lichen, which is much more difficult to remove from the shingles. I will cover that much more in depth in a different article regarding roof cleaning.
How Do I Know I Need To Replace My Roof?
Aside from leaks, or obvious storm damage (like a tree hitting your home), how else can you tell that your roof is approaching the time to be replaced?
What Do Tires And Shingles Have In Common?
You know how when the tread on your tires is getting dangerously low, the tread indicator bars start to show through telling you that it’s time to replace the tires? Shingles also have a “tread indicator”. This is “degranulation”.
Degranulation is one of the first ways that many homeowners realize that they need to replace their roof. As soon as a roof is installed, it will start to lose its granule aggregate. These granules help protect the asphalt and fiberglass mat from damaging UV rays, as well as give the roof its beautiful coloration.
If you look at your shingles in the bright sun, you may notice that they are a bit shiny. This is the fiberglass mat starting to show through because the granules in that areas have worn off.
I tend to compare degranulation to the wearing of tires. The granules are the tread, and as it wears down, you can see some of the shininess of the fiberglass mat showing through. You will typically see degranulation on the ridge caps first, with architectural shingles developing it along the edges within year or so after you notice it on the ridge caps.
The Stress Of Protecting Your Home
Of course, as your roof ages, it is more likely to have cracked or damaged shingles. These can be from any number of causes, such as tree limbs rubbing against the roof, to improper ventilation, to thermal expansion and contraction through our brutal Texas summers. As your roof ages, these shingles become more and more difficult to repair, not only because of the color difference between the aged shingles and the new shingles, but also because the adhesives from the aged shingles are less likely to properly adhere to the new shingles.
Because the ridge cap shingles experience the stress of being bent to conform to the ridge, as well as being at the high points of the roof, you will often notice excessive wear on them before the remainder of the roof. You can extend the life of the ridge caps by using premium ridge caps, such as the GAF TimberTex ridge cap. The TimberTex ridge cap also is made to age at approximately the same rate as the architectural shingles, so this will help postpone costly repairs that otherwise might need to be made.
Self Inflicted Nail Wounds
If you notice that some of your shingles appear to be lifted or “tenting” in the middle, the cause might be from nails that are backing themselves out of the roof deck. While initially a simple repair, if left unchecked, the nails will eventually back themselves fully out, punching a hole through the shingle that water can then use to enter your home. By resecuring and resealing these shingles before the nail fully penetrates the shingle that is covering it, you can prevent some major issues.
The Obvious: A Leak
Many roofs end up being replaced only after a leak has caused damage to the house. While some of these are not preventable, many of them could have been stopped with just some regular maintenance.
Maintenance Can Do Wonders
An often overlooked indicator that your roof is aging is when your vent flashings start to exhibit wear. This can be rust showing on the galvanized flashings, the caulking failing on water heater or furnace vents, or even cracks and holes that develop on the rubber boots that surround the PVC plumbing vents. Regular maintenance will often help to prevent some of these issues, as well as minimize the need for replacing these vents until it is time to replace the entire roof.
When meeting with new clients, I stress the importance of maintaining their new roof. Think of it as an oil change for your roof once every few years.
While a one size fits all approach isn’t appropriate for most roofs, there are some common items that will help to extend the life of your roof. I will cover maintenance items more in depth in a later article.
It’s Important To Vent
If your ventilation is inadequate, your shingles will age faster. Inadequate ventilation can allow excess moisture to build up in your home. This moisture can contribute to rotting out your siding, and in extreme cases, rotting out the plywood decking that your shingles are installed to. You may also have issues with keeping pilot lights on furnace and water heaters lit, as well as condensation issues. Making certain that your ventilation is appropriate for your roof is key to extending the life of your shingles.
Sometimes, your ventilation needs will change from when the roof is initially installed. One example is that the motors on power vents occasionally burn out prematurely, which causes them to stop moving air and moisture properly. Unfortunately, replacement motors are rarely available for power vents, which means the entire vent will need to be completely replaced. Another example is if a bathroom is added to a section of the house where there wasn’t one previously. This extra moisture can cause issues in the walls and attic.
Until next time,
Travis Diekmann
The Texan Roofer