contact us
 League City
Hill Country
 Golden Triangle
Lake Charles

January 19, 2021

A Quick Guide to Roof Stains

A solid roof is your first line of defense against harsh outdoor elements, like hail or rainfall. You can imagine how dismaying it is to see the protective covering of your house gradually start to change in appearance — a telltale sign that your roof is becoming vulnerable to the effects of inclement weather over the years. A common culprit of aging in a roof, water or moisture can leave unsightly stains that do not only decrease the curb appeal but also compromises the security of your home if left untreated.

A professional storm damage specialist can determine the cause of roof discoloration by properly identifying the location and color of stains or marks. After inspecting the structure and learning the source of the issue, the roofer will help you come up with the best solutions that are fit for your unique needs.

a guide to roof stains

Green or Black Roof Stains

Check the condition of your roof from the ground up. Do you notice green- or dark-colored stains plastered all over the surface of the roof? These stains indicate the presence of growing organisms, such as algae or moss. 

Across the eastern half of the country, roof shingles tend to grow a species of algae named gloeocapsa magma. It takes shape in streaks or patches of slime, a moist and slippery substance, that can appear anywhere from blue-green to solid black. The presence of excessive moisture and sunlight makes for an ideal harvesting area for microorganisms. Fortunately, roof algae alone do not pose a significant threat to the overall structural integrity of the roofing system. Unlike mold and mildew, algae do not endanger your home or the health of the residents.

However, these microorganisms can lock in unwanted dampness or invite other, larger creatures to wreak havoc on the roofing structure, making it an urgent problem that needs to be solved during the next routine maintenance visit or with a total roof replacement.

To clean it, oxygen bleach or a solution of trisodium phosphate often does the job. Power-spraying or scrubbing the stains on your own is possible, but likely to cause further irreparable damage. It is a good idea to have a professional roof cleaning service take care of this part of maintenance for you. 

To prevent algae from forming and spreading, you are in need of a little bit of chemistry. Algae find trace minerals copper and zinc abhorrent, so make sure to add some small sheets of copper or zinc to the peak points on the roof right above the discolored areas. During a slight rainfall, the water washes the metallic atoms over the roof and lets them trickle down below, killing and preventing the formation of algae without anyone having to lift another finger.

White or Yellow Roof Stains

Do you see white- or yellow-colored stains on your roof when you inspect it from afar? In many cases, this particular discoloration suggests hard water buildup from an air conditioning equipment or evaporative cooler. It occurs on the lower areas of the roof beneath the cooling units and sticks out like a sore thumb. 

Water is considered “hard” if it shows a high concentration of dissolved minerals like calcium or magnesium. If your home has hard water, you will notice mineral deposits or white stains on different surfaces around the interior and exterior of the house. While hard water does not pose an immediate health risk, the buildup of mineral deposits it leaves behind can reduce the efficiency of your roof equipment and make the exterior look of your home appear unkempt, says a roof replacement expert.

Similar to algae-type stains, attempting to power-wash or scrub the roof surface can potentially make things worse. Instead, you can try fading the traces of damage with a vinegar solution, which works to slowly dull mild stains without posing risks to the animals or plant beds around your house. If you feel like using harsher home remedies, make sure to consult a roofer and inquire about the better solutions that adhere to shingle manufacturer specifications.

Other Causes of Roof Discoloration

Apart from algae, moss and hard water buildup, there are other issues that can cause the appearance of stains on a roof. Here are some clues to help you identify the main culprit and come up with the appropriate solutions that will last you for a long time.

  • Rust or Chimney Soot Stains. Are there any red or brown spots hugging a portion of the chimney sitting on top of your roof? This is a clear indication of rusting, a common type of roof staining problem. To sort it out, thoroughly clean the affected area and treat it with oxalic acid. This will help diminish the appearance of rust and even prevent it in the future.

  • White Stains on Slate Roofs. Efflorescence, or the powdery deposit of salts from rainwater, is often visible on concrete and natural stone surfaces. These specks of white-colored crystalline can sometimes appear on roof tiles or shingles. Fortunately, efflorescence is removed by natural weathering processes — as rainwater is slightly acidic, it gradually dissolves and washes away the deposits. 

If you want to dissolve efflorescence a lot quicker, applying pressurized water may do the trick, but remember that most roof repair professionals will not advise homeowners to take on the do-it-yourself route due to potential damage that may arise.

  • Trees and Plant Debris Stains. If you see stains or unusual patches near large, overhanging tree branches on your roof, they may be due to seeds, berries, leaves and other debris falling and then decaying on the surface. A roof that has obvious draining problems resulting in ponding water is also an attractive spot for moss to thrive. Moss grows where water collects, even in south-facing areas, and under big, shady trees. 

The most effective method of cleaning moss from a roof is with a mixture of bleach and water. Apply it with a sprayer, allow the solution to dwell on the surface for 15 to 20 minutes and then rinse thoroughly with low-pressure water. To do this technique properly, make sure to schedule a maintenance appointment with your local roof repair contractor.

  • Light Spots on Roof Shingles. Over time, black or dark-colored asphalt shingles may appear lighter and patchy due to natural aging, varying weather conditions or poor maintenance practices. If you see that your roof shingles appear inconsistent and unappealing, it is time to roll your sleeves up and get to inspection. Look in the gutters for signs of ceramic granules, the protective coating of asphalt shingles, that have washed off. Also, check if your shingles are curling, cracked or broken. There are many things that point to the direction of needing a roof replacement soon, so make sure you watch out for all of them.

Contact Us for High-Quality Roofing Services Today

Transform the look and feel of your home with a quality roofing makeover. Redemption Roofing is the premier source of top-rated roofing solutions, such as asphalt shingles installation, storm damage roof repair and routine maintenance, in many Texas areas. Our dedicated team aims to provide the safe and pleasant living space that every homeowner deserves using industry-leading products and services. 

Call us today at 936-226-0658 (North Houston), 830-522-4145 (Hill Country) or 281-214-3026 (League City). You may also fill out our contact form to set up an appointment.

2114 McCaleb Rd., Ste. A-500, Montgomery, TX 77316
North Houston Phone: 936-321-3733
17080 Texas highway 46 #117 
Spring Branch Texas 78070
Hill Country Phone: 830-214-7779
2600 South Shore Blvd, #300
League City, TX 77573
League City Phone: 281-214-3026
Golden Triangle Phone: 409-403-5073
8:00am-5:00pm, Monday-Friday

Contact us today!
Gaf Master Elite
© 2021 Redemption Roofing | Designed By Pinpoint Marketing