Residential Roofing Tips

Why is My Asphalt Shingle Roof Stained?

Ever wondered where that black staining on your asphalt shingle roof comes from? And even more importantly, how to fix it? If you answered yes to either of these questions, then this post is for you. If you are a new homeowner or new to asphalt shingles, you may not be familiar with how to handle the stains that can build over time. Let’s break down how the staining gets on your roof, where it comes from, and how to resolve it.

Roofing materials all have their pros and cons and almost all roof types are susceptible to discoloration. Something to keep in mind if you have an asphalt shingle roof, or plan to have one installed soon, is that staining will occur. The black staining is unavoidable and is something you’ll need to maintain over the years.

What are Those Stains?

The black stains on your asphalt shingles are actually caused by blue-green algae. It feeds on the limestone found in the shingle granules. The good news is, it’s only a cosmetic issue. It might be unsightly, but it shouldn’t ever affect the performance or longevity of your roof.

An additional issue that we often see is moss growth. The blue-green algae give the moss a foundation to grab onto, and this can be a growing issue (pun intended!) if you don’t address it in a timely manner. Remember that any surface that is damp and warm without direct sunlight can support algae growth.

How to Treat Algae Growth on Your Roof

There are several options for avoiding and treating algae growth on asphalt shingles. Most asphalt shingles on the market today are made with algae-resistant compounds. The granules in these shingles are coated with zinc or copper oxide which kills algae and prevents staining and moss growth. For homeowners considering this option, it’s important to note that the algae resistance on these shingles will only last about 10 years.

If you already see algae staining on your roof, you can opt to clean it. One option is to clean using a DIY solution made from bleach, water, and trisodium phosphate. The ingredients may vary between shingle manufacturers and solutions range from one-gallon bleach, five gallons of water, and a dash of TSP to 2.5 gallons bleach and water and 1 cup TSP. Spray the solution on the roof, let it sit for 10-20 minutes, and rinse off with a garden hose. NEVER POWERWASH your asphalt shingle roof. Keep in mind that cleaning the shingles isn’t a permanent solution and you’ll need to repeat the process every 3-5 years.

Cleaning a roof can be a difficult and dangerous job and we recommend hiring a professional to tackle it for you. There are numerous roof cleaning services out there and we’re glad to provide recommendations. Contact the Bond Roofing team if you’d like to speak to a team member about your roofing needs.

Residential Roofing Tips

The Pros and Cons of Asphalt Shingles

Building a home or looking into a roof replacement? Asphalt shingles are a popular roofing choice. Asphalt shingle roofing is likely the most widely used roofing system in the United States, covering nearly 70 percent of residential structures.  There are several positive reasons to choose asphalt shingles, but like most anything else, there are some cons as well.

The Pros

  • Economical – Asphalt shingles are one of the most economical roofing materials you can choose, which is why most people select them. The initial cost is much lower than a metal or flat roof due to lower material costs and ease of installation.  With asphalt shingles, you get high performance for a low-cost.
  • Versatility – Asphalt shingles can be applied to all sorts of shapes and roof slopes and are suitable for a variety of climates and environments. 
  • Wide Variety of Style and Colors – If you seek a unique look, you can achieve that with asphalt shingles. Because they come in such a wide variety of styles and colors, you’ll be sure to find a combination that suits your home. If energy efficiency is a priority of yours, there are even solar reflective energy-efficient shingles on the market. 
  • Fire, Wind, and Impact Resistance Options – When it’s needed, higher-end shingles with increased protection from the elements are available at a relatively low-cost difference. 
  • Ease of Repair – Just as asphalt shingles are easy to install, they are also easy to repair.  With specialized systems like metal, slate, tile or wood shake you might have a hard time finding a roofer and the material to make a repair.  Most roofers can make a shingle repair and the shingles themselves are widely available.

The Cons 

  • Relatively Short Service Life – Asphalt shingle roofs will last 15-30 years before you’ll need to replace the whole roof. This might seem like a long time but is relatively short compared to the service life of copper, tile, or slate roofing, which can last up to 100 years. 
  • Lower Wind Resistance – Ok, we mentioned this as a pro for shingles and there are some options for increased wind resistance with asphalt shingles, but if you live in an area with the potential for strong winds like the beach or the mountains, you might consider other options like metal or tile.
  • Not Suitable for Low Slopes – This con doesn’t apply to most homes, but a roof must have a slope of at least 2:12 to be suitable for asphalt shingles. Otherwise, water buildup could damage your roofing, structure, and home. 
  • Not as Energy-Efficient – Unfortunately, asphalt shingles will not be as energy-efficient as metal or white flat roofs. Shingles are much better at absorbing heat than reflecting it, even when painted a lighter color. If energy efficiency is what you’re after and you’d like asphalt shingles, consider a solar reflective shingle. 

Now that we’ve reviewed the top pros and cons of asphalt shingles, we hope your roofing decision will be made a bit easier. If you have any roofing questions or you’d like to set up a consultation, contact the Bond Roofing team