Directions: |
Directions:Most recommend a bleach and water mixture to kill the mold after cleaning the walls. I used bleach for years, and it is not very effective, and it is harmful to the walls.
New products came out that are better than bleach, are not harmful to the walls and vegetation, and are environmentally safe. The information I saw recommends the garden hose to wash and garden sprayer to apply the chemicals. If using a garden sprayer, you could not apply the chemicals fast enough. You can't cover much area before the chemicals need to be washed off, or the chemicals dry up.
The only effective way to remove mold and stains is using a power washer. This gives you a high pressure wash which is very effective, and there is a tube on all power washers you can put in your chemicals to cover the entire wall without drying up before you can wash it all off with the power washer. This eliminates the ineffective garden sprayer, and keeps the chemicals from dripping onto the do-it-yourself person.
Step 1 - Gather Your Tools
So using a power washer is the superior and only correct way to remove mold and stains. I checked with my local rental center, and power or pressure washers are inexpensive to rent. A 2000 psi power washer rents for $33 a day, and a 5000 psi washer is $55 a day. I recommend the 2000 psi washer. A novice could cause problems for themselves using the 5000 psi, even knocking off some of the stucco.
You will require some other equipment to accomplish your task. Go to the auto supply store and buy a car washing brush. They are inexpensive, and you can keep them to wash your car with for years to come. Car washing brushes have soft bristles, which you want, as opposed to a stiff bristle brush. A 4 to 8 foot extension pole and a 10 to 20 foot extension pole will be needed. You will also need a 6 foot step ladder, and a 16 foot extension ladder. You need these to reach the higher parts of the wall. Also you should ask the rental center to rent you extensions for the pressure washer tip to reach the higher parts of the wall. Get a 50 foot garden hose for the power washer. Two people are needed to use the power washer. One person will use the tip of the power washer, and an assistant moves the power washer and hose, and keeps the chemical solutions coming with the uptake hose on the washer. Pressure washers have a gasoline motor, so you will need some high octane gasoline, and a can to hold it.
Step 2 - Prep the Walls
Put up the storm windows on the older type windows, and make sure no screens are exposed. Small pieces of the stucco wall, and mortar from brick walls may be knocked off and get stuck in any screens.
Step 3 - Spray and Rinse
Begin the process by power washing the entire house you are working on with water only. This alone will wash off a lot of mold and stains. Use the medium pressure tip on your power washer for best results. Next use the washing chemicals and the scrub brush to remove the mold and stains. Try to work on an overcast day so the sun doesn’t dry up the washing solution before you're done washing. Then use the power washer to remove the chemicals. Take a break, and let the entire house dry up before applying the chemical used to keep the mold and stains from coming back. Let the chemical sit on the wall for the time recommended on the chemical bottle. Then wash it off completely, and you have successfully completed your task in the best possible way.
Step 4 - Address the Cause
For a further note, let’s deal with the problems that cause the mold to grow. Mold grows in moisture, so cut back the shrubbery close to the wall. Check your chimney cap to make sure it is not letting moisture into the walls. For brick walls, make sure the mortar is sound. You may have to tuck point, also known as pointing. There is a special trowel tool for this. Use it to remove any loose mortar, and apply fresh mortar with the tool. Let the mortar cure for at least 48 days, then you can apply a clear concrete sealer on the brick. Stucco walls may have settlement cracks, and you can fill these with stucco colored caulk. Let the caulk cure, then apply the concrete sealer. Trees and shrubs close to the walls can allow moisture to build up, and mold needs moisture to grow. Deal with the moisture, and you will have dealt with the mold problem. Now you are completely done. Good work. |
This recipe for Removing exterior mold from stucco and brick is from