Many residents are surprised by the idea of Richmond roof cleaning. Reasons for cleaning include aesthetics, property values, energy efficiency, and increased longevity of the roof.
Whatever the main reason, if it is going to be done, it is in your best interest to know what choices are available to you. A quality roof should last upwards of 30 years if cared for and maintained properly. Unfortunately, many roofs are subjected to unnecessary stress while cleaning that greatly reduces the life expectancy of the roof. With repeated roof cleaning comes certain pitfalls that every homeowner, property manager, and professional cleaner should be aware of in order to avoid damage to property, unnecessary repair costs, and the premature replacement of the roof.
WHY HAS THE ROOF TURNED BLACK?
The black streaking typically found on homes in areas where moisture settles on shingles is not caused by mildew or fungus; it’s roof algae. 3M scientists have identified the most common form as Gloeocapsa Magma. Algae spores are carried by the wind, which is why so many houses in the neighborhood can end up with this problem. During the last 20 years, this particular algae strain has become hardier and has been able to migrate to less humid environments than it has in the past. And in areas where it traditionally has been found, the staining is showing up earlier, is more severe and settles on a greater number of roofs.
HOW CAN IT BE CLEANED?
Typical roof cleaning methods involve either pressure cleaning or chemical solutions containing Chlorine Bleach or Sodium Hydroxide. If used properly, these methods will clean the roof with minimal adverse impact.
WHAT IS THE BEST CLEANING METHOD?
Each method has its advantages and disadvantages.
A chlorine and water solution can be used, followed by a thorough rinse. Of course, since chlorine can be toxic to people and plants, proper care should be taken to protect employees and the surrounding property from overspray and runoff. The benefits to using chlorine include a much faster cleaning process and minimal rinsing as compared to other methods. This translates into much less wear & tear on the roof – particularly asphalt shingle roofs.
Sodium Hydroxide based cleaners are generally advertised as safer for the landscaping, but sodium hydroxide is caustic, very toxic, and care should also be used to protect employees and surrounding property. Sodium hydroxide is also a very effective degreaser. High levels of sodium hydroxide in a cleaning product can cause damage to an asphalt shingle roof that can be irreversible. These products generally require much more rinsing than the chlorine method. The rinsing process is not only time consuming, but it can also be potentially damaging to the roof if not done correctly. A quality sodium hydroxide based product should not require any more than 100 psi to effectively rinse an asphalt shingle roof and even then some granule loss should be expected.
Pressure cleaning is an option that should only be used on a concrete, barrel tile, or metal roofs. Pressure cleaning has the advantage of not requiring chemicals, which eliminates some of the cost – in addition to landscaping and chemical exposure concerns. The down side to pressure cleaning is that it is very time consuming and it exerts tremendous force on a surface that is not really designed to handle it. In addition, repeated pressure cleaning can wear away the surface of some tiles that are only covered by a thin layer of coloring. When this happens, the grey concrete color starts to show through and the roof must be stained or painted.