Roof Cleaning Chemicals

[EmpirePW 14]

I got a call today about cleaning the discoloration on an asphalt shingle roof. What is the best way to do a job like this? would it be low power and what type of chemicals would be best to use as well as where would be a good supplier to order those chemicals in the southern part of the US (I live in North Carolina). There are no gutters so the runoff will be into their garden and yard so enviromental friendly chemicals would be best. Would it be best to apply chemicals with a pump yard applicator or to run them right through my pressure washer? Are there sealers I would use on the roof to help preserve it? If anyone could be kind enough to take a few minutes and explain to me the best way to go about a job like this I would really appreciate it. I've only done siding work and surface cleaning and I am looking to learn all types of services I could offer and I think this could be a big seller in my area. Also I don't know what the prices of the chemicals are and I use the customers water so if you could tell me how much you would charge per foot for a job like this that would be great.

Thank You,

Matthew Krupitzer

Empire Pressure Washing

[Firedkm 14]

Mathew,

There are two popular ways of cleaning asphalt shingles.

1. Using bleach (4%-6%) and flooding the roof with it. You really should have two people doing this. One on the roof and one on the ground. The ground person should be rinse the side of the house down and the surrounding landscaping so you dont burn or kill the plants. After you flood the roof with bleach and let it dwell for awhile then you go back rinse the roof with water. Using a garden hose if fine for this. This is the recommended way by the shingle manufactures.

2. Using a sodium hydroxide cleaner. You coat the roof with this cleaner and let it dwell for 15 minutes or so. Then go back and rinse with at least 500 psi. When I use this method I have a Pitch Witch. This mounts on a extension pole or your wand. This works great at rinsing the roof.

I use both ways. The bleach works faster and is easier to do. You get good results doing it this way.

Doing the sodium hydroxide takes more time but the results are better than using bleach. The only downside to this is the pressure you need to clean the roof.

[EmpirePW 14]

Thank you. 2 questions though. When you say bleach (4%-6%) is that the ratio that I should dilute it too or is that a type of bleach? And with the Sodium Hydroxide cleaner what is the highest pressure it would be safe to rinse with? I have a 1000 psi cold water unit but would that be too much and start tearing fiberglass off the shingles?

Matthew Krupitzer

Empire Pressure Washing

Mathew,

There are two popular ways of cleaning asphalt shingles.

1. Using bleach (4%-6%) and flooding the roof with it. You really should have two people doing this. One on the roof and one on the ground. The ground person should be rinse the side of the house down and the surrounding landscaping so you dont burn or kill the plants. After you flood the roof with bleach and let it dwell for awhile then you go back rinse the roof with water. Using a garden hose if fine for this. This is the recommended way by the shingle manufactures.

2. Using a sodium hydroxide cleaner. You coat the roof with this cleaner and let it dwell for 15 minutes or so. Then go back and rinse with at least 500 psi. When I use this method I have a Pitch Witch. This mounts on a extension pole or your wand. This works great at rinsing the roof.

I use both ways. The bleach works faster and is easier to do. You get good results doing it this way.

Doing the sodium hydroxide takes more time but the results are better than using bleach. The only downside to this is the pressure you need to clean the roof.

[R. Williamson 14]

Use a larger orifice nozzle to reduce your pressure.

[Firedkm 14]

Matt,

Yes I diliute pool chlorine to the percentage I need.

You only need about 500 psi for the rinse with the sodium hydroxide cleaner. 1000psi would be toooo much. You need to get a larger tip to reduce the presuure on your machine. Depending on the gpm your washer is will depend on the tip size you need to get that pressure.

[Henry B. 4]

Hey Matt,

You said you had a 1,000psi cold water unit? How many gallons per minute does it put out? Your going to want at least 4gpm or your going to be there all day rinsing it properly.