Quick Menu:
What are those black streaks on my roof?
Why should I clean it off?
Will pressure washing do any harm?
Are your chemicals safe??
How do I figure the cost?
Do I need to do anything first?
How long does it take?
Service and Locations
Do you have references
Are you Insured?

What are those black streaks on my roof?

Dirty roof Clean roof

Most of the black discoloration on your roof is caused by a species of algae called " Goleocapsa Magma". This algae is transported through the air and is prevalent in all areas but particularly in warm humid climates such as ours here in Houston. It is a living organism that feeds on limestone and limestone is one of the primary ingredients in the manufacturing of asphalt shingles.

The algae generally starts on the North side of the house and shaded areas. You usually don't see it around and under metal roof jacks because it hates metal. When it rains the water hits the metal jack and then runs down kills the algae under the jack. That's why it is clean under the jacks. That's the original color of your roof. And that is what yours will look like after we are finished cleaning your roof!

Green stains on roofs and siding are a result of mold and mildew and are also most prevalent in warm humid climates.

The algae and fungus alone can cause the roof's life to be cut up to half due to premature granular loss. This can drive up the cost of future shingle repair and possible roof replacement.

Our Soft Wash cleaning system has been shown to restore the integrity and function, adding years on the life of the roof.

Why should I clean it off?

There are several reasons you should clean your roof periodically.

1. Appearance. When you view your house from the street a large part of the view is your roof. No matter how nice your house looks a dirty roof stands out.

2. Health. If you have allergies and you have a dirty roof. You have a mold farm growing on your house. Every time it rains the water that drips off your house is contaminated with mold and allergens.

3.Roof Life. Left untreated. The shingles will hold moisture and cause the granules to dislodge and become brittle and crack. So a roof that is designed to last 25 to 30 years will only last 12 to 15 years.

4.Energy costs. A dark stained roof will result in higher electric bills. Shingles are designed to reflect or divert exposure away from your home. The lighter the color and more reflective the surface the more effective. Where dirt exists the light is retained and transfers as heat into the home, stressing insulation and air condition/heating systems. Over the span of the entire roof the stress becomes enormous and costly.

Will pressure washing do any harm?

Yes! The worst thing you can do is use a high pressure washer to clean your roof.

1. This method will remove a lot of the granules and also cause streaking and scaring of the shingles greatly reducing the life of your roof.

2. Pressure washing your roof will not kill the algae. It only removes the already dead waste produced by the algae, resulting in the algae coming right back as soon as 6 months later.

We here at The House Doctor of Houston use the Low Pressure Soft Wash cleaning system. We use a totally safe, bio-degradable, environmentally friendly product that is not harmful to plants, animals, or humans when applied properly. We then rinse the roof with about as much pressure as a hard rain causing no damage to the shingles. With the equipment we have we are able to do this entire process from the ground. We rarely need to get up on your roof. This greatly reduces the chance of an accidents.

You should always use a chemical and Soft Wash cleaning process for your roof. Roof cleaning is a completely different trade from pressure washing requiring different pumps, plumbing, hoses, nozzles, valves, chemicals, caution, knowledge, experience, skill, and insurance. We have all of the necessary tools, and have learned from the best roof cleaning professionals in the country.

Are your chemicals safe?

YES: Our chemicals are specifically formulated to provide the highest level of cleaning power, yet are 100% safe... they will not harm your children, plants, or animals.

Our product does not contain chlorine. Chlorine is harmful to plants, animals, and humans if not diluted properly.

Chemicals on roof

How do I figure the cost?

For the No pressure soft wash cleaning service we charge 15cents per foot or $ 15.00 a square. Roofers talk in terms of squares which is a 10x10 area. If you happen to know how many squares you house is just multiply $15.00 by the number of squares and that is your cost. If your house is 24 squares 24 x 15= $ 360.00.

If you do not know how many squares your roof is a quick way to estimate it is to add your living space and add 500 sq. ft. for a 2 car garage and multiply that number by 1.20 for the pitch of the roof. 1400 sq + 500 = 1900 sq ft x 1.20=2280 x 15 Cents =$ 342.00

For a 2 story house you must measure the outer perimeter of the house and garage and multiply that number by 1.20 for pitch and the x by .15.

For steep pitch roofs multiply your total sq ft by 1.40 for the pitch and then x 15 cents per ft.

If the math is too much for you don't worry we will be happy to drive out and give you a free estimate. Just give us a call or go to the request a quote page.

Do I need to do any thing first?

Yes. It would make things a lot easier if you could do a few things the night before we come.

1. Park vehicles in garage or on street.

2. Put all pets inside or out of the way.

3. Put any delicate plant out of the way. Any plants in big pots that are hard to move we will be happy to assist in moving or protecting.

4. Put any lawn furniture, equipment, and toys up or out of the way.

How long does it take?

Most jobs only take 1 day. Weather permitting. Our cleaning products only work on a dry roof.

Service and Locations

We are located in the South East Houston area . We service all of Houston and its surrounding area. The majority of our business is in Clear Lake, Friendswood, Pearland, League City, Pasadena, Sagemont, Alvin, and Hobby Airport Area. We have been in business in Houston, Texas since 1978 and serving the South East area since 1995..

Our service is backed by years of experience, knowledge, safety, and commitment.

Do you have references?

Yes. References are supplied by contacting us.

Are you insured?

Yes we are insured. Certificates furnished upon request.