Frequently Asked Questions

Q: Are you licensed and insured?

A: Yes.  We are licensed to do business in the state of North Carolina and are insured.  We can provide any necessary documentation upon request.

Q: Why does my roof turn black?

A: Gloeocapsa Magma is the primary species of Algae causing your roof to turn black.  These Algae spores are carried by the wind and land on your roof.  As it grows it will spread to adjacent homes which is why you will see it on so many roofs in the same area.  It thrives in warm, humid environments like the Carolinas and normally appears on the north facing slope or shaded areas of your roof where the lack of sun supports its growth.

It has three requirements to grow: Heat, moisture and nutrients.  Gloeocapsa feeds on inorganic materials like the limestone fillers found in asphalt shingles.  As it feeds, it grows and spreads across your roof.  That black streaking you notice is the algae traveling across your roof. 

Q: Will this algae damage my shingles?

A: Yes.  Over a period of years it will spread across your roof, turning it black and eating away at the shingles. As it eats, it loosens the protective layer of surface granules which play a very important part in solar reflectivity.  The loss of these granules combined with the black growth spreading across you roof will cause your roof to heat up quicker on a sunny day.  While this might be fine in the winter, it can be a source of higher electric bills in the spring and summer months as your air conditioner struggles to keep up.

Q: Can my roof be cleaned?

A: Yes.  Roof Refresh can help you get those stains off of your roof.  We use only methods approved by The Asphalt Roofing Manufacturers Association.  Here is a link to a technical bulletin issued by ARMA on the correct method to use when cleaning a roof. http://www.asphaltroofing.org/pdf/tb_217.pdf We use no pressure cleaning equipment when cleaning a roof.  Everything we do is done with low pressure and rinsed with large volumes of water.

Here is a link to a blog I wrote on the subject. This is information I have picked up from professionals in our industry over the years. Roof Cleaning Raleigh Cary

Q: Does chemical cleaning damage my shingles?

A: This is one of the most important questions you can ask.  It is the source of much debate in our industry and it gets a lot of attention.

The short answer is absolutely not.  If you have a professional roof cleaning company clean your roof, you can expect good results. If you do enough roof cleaning research on the internet you will find that everyone has an opinion on the subject

In a nutshell, there are two methods predominantly used by most roof cleaning professionals.   (There are a few companies out there that use “all natural cleaning methods” but we have no idea about their products and their efficacy).  We will attempt to give you a quick, impartial run down on the two primary methods used to clean roofs.   

Method #1

Using Sodium Hydroxide to clean your roof.  Sodium Hydroxide is known as lye or caustic soda.  It is also a degreaser.   There are a few roof cleaning companies that use it effectively in a somewhat diluted form to clean roofs.  It is supposed to be safe for plants and animals.

As far as we can tell, it is an effective roof cleaner.  When it is applied to a roof it will turn the black stains blacker.   The only problem, is that every square inch of the roof then needs to be walked and rinsed with low pressure to remove the stains.  If you search the internet there are a few websites that have videos showing the process.   

Method #2

Using Sodium Hypochlorite to clean you roof.  Sodium Hypochlorite is a chlorine compound that is used as a sanitizing agent.  Most roof cleaning companies will tell you that sodium hypochlorite is the preferred method for cleaning a roof.   It is applied in a diluted form with a sprayer and then rinsed with high volumes of water when it has done its job.   If it is used correctly, it can be a powerful roof cleaner. 

The biggest myth you will read or hear about sodium hypochlorite is that it damages shingles by “drying them out and making them brittle”.  This is one of those cleverly worded “catch phrases” used by detractors of Sodium Hypochlorite.  You will see it used a lot, but never with any sort of factual references to back it up.  In other words, it is nothing more than a gratuitous assertion.

Take some time and do some internet key word searches on both products.  Once you delve deep enough into it, you will see that it boils down to which product a roof cleaning company thinks works best for them.

The pitch on most of the roofs in this area will not allow us to safely walk on them, so the sodium hydroxide method is not one we prefer.  We believe that Sodium Hypochlorite is a better cleaning agent and since it is the only recommended method endorsed by the Asphalt Roofing Manufacturers Association, it is our preferred choice for cleaning roofs.

Q: Will the chemicals kill my plants and shrubs?

A: We will take every precaution to prevent damage to plants, shrubs and grass.  We will wet and cover possible affected areas with plastic tarps in advance.  As the job progresses we will rinse as required to protect vegetation and then rinse some more.  The rinsing dilutes the mixture enough that we don’t have much to worry about.  If you do not have gutters on your home we will tarp all of the bushes and plants.

We will always have at least two men on a given job.  One works the roof, the other works the ground.  The ground man is responsible for keeping everything wet in case of overspray etc.  It is very seldom that we have a problem but it is not impossible.

Q: Do you clean gutters?

A: Yes, we will clean the interior and exterior of your gutters. The black streaks or "Tiger Stripes" on your gutters are caused by an electrostatic bonding process that is a result of run-off from your roof. Ask about it when requesting an estimate.