All you have to do is dissolve about a cup of low phosphate detergent into 5 gallons of water and then wash your door.
Power washing garage door.
Do not use harsh or abrasive detergents.
Start from the back of the garage and gradually push the dirty water outside.
The high pressure will force the majority of the water outside.
With a soft sponge or cloth apply the soap to the door in a circular motion.
Pressure washers use 80 less water than a garden hose.
Electric power washers are safer than gas for use in enclosed spaces like in a garage start with a thorough sweeping to remove loose debris begin using your power washer at the back of your garage closest to the house and move forward toward the door.
You may also choose to use a pressure washer at a very low pressure setting.
Use a pressure washer.
For steel or fiberglass doors apply a light coat of spray car wax.
This can damage the painted surface of the door or the seals.
Wash both the interior and exterior using a sponge cloth and or soft brush.
Switch to high pressure and start spraying.
Working from the bottom panel up wash the steel garage door with a cloth or sponge soaked in the cleaning solution.
Using a clean bucket mix a small amount of dish soap or car wash soap preferred with water.
Wash the door surfaces and windows of your garage with a mild liquid soap such as a car washing soap or dish washing soap and water.
You don t have to flood your garage to get it clean.
Rinse off with garden hose.
Don t use a pressure washer.
If the door is very dirty or mildew stained you can also use a very soft bristled brush.