Why Mr. Mister? Why not "Bob" from down the street?
We all have a friend, or know of someone locally, who does work on the side...sometimes that persons name is Bob; he says he can pressure wash your house for $80 and do your driveway for another $20. I'm 100% certain he can do just that. However, I ask you to take into account the information you gain here today.
Cleaning with just water is a momentary fix. Mildew and algae all develop a root system...literally growing into your home siding. Blasting it off with pressurized water will remove what is on the surface, but you'll see it coming back in as soon as 4-6 weeks...and back to visibly "green" shortly thereafter. The only way to completely remove it is to neutralize it chemically...basically to kill it.
If Bob is semi-knowledgeable he probably has a gallon of Clorox, some dish soap, and a machine he either had or picked up because it was on sale at Home Depot. Mr. Mister has a trailer full of commercial grade chemicals that you can't buy from a regular store, as well as a commercial quality machine modified for this specific industry. The precise mix of chemicals and detergents are designed to be sprayed on at low pressure, they then neutralize organic matter, loosen it from the surface along with dirt/grime, and rinse it away with a high volume stream of water.
Cleaning with just water is a momentary fix. Mildew and algae all develop a root system...literally growing into your home siding. Blasting it off with pressurized water will remove what is on the surface, but you'll see it coming back in as soon as 4-6 weeks...and back to visibly "green" shortly thereafter. The only way to completely remove it is to neutralize it chemically...basically to kill it.
If Bob is semi-knowledgeable he probably has a gallon of Clorox, some dish soap, and a machine he either had or picked up because it was on sale at Home Depot. Mr. Mister has a trailer full of commercial grade chemicals that you can't buy from a regular store, as well as a commercial quality machine modified for this specific industry. The precise mix of chemicals and detergents are designed to be sprayed on at low pressure, they then neutralize organic matter, loosen it from the surface along with dirt/grime, and rinse it away with a high volume stream of water.
If Bob tells you about all the PSI (pounds per square inch) his machine can put out, BE WORRIED. Using high pressure on siding, windows, or shingles will not only void any warranty, it can also create irreversible damage that will cost you far more to repair in the long run. High pressure should NEVER be used to clean siding. Mr. Mister relies on GPM (gallons per minute), or the volume of water to clean. The average "Home Depot special" pressure washer is about 4000psi at 2.5gpm, Mr. Mister's is a modified 3000psi at 8gpm. Chances are Bob is either going to need a ladder, or the peaks of your house are going to still be dirty when he leaves, not to mention the possible pressure marks he leaves all over the bottom half of your house. Mr. Mister can hit the third-story eaves of your house while standing on the ground, no ladder needed, all the while maintaining a safe distance of around 10' from the closest point.
Is "house wash mix" mostly bleach? In a way...yes. Bob might have Clorox's top of line bleach, but what it lacks is potency, and what he lacks is efficiency. The active working ingredient in bleach is Sodium Hypochlorite, which degrades over time. Clorox is only about 5% Sodium Hypochlorite and can sit on a shelf for months. Mr. Mister uses fresh 12.5% straight Sodium Hypochlorite, and uses a special pump/injector to apply it. The secret is in the dilution; starting with fresh 12.5% chemical a final solution of just 1% is enough to clean without harming plants or landscaping. The commercial grade pump/injector allows heights of 40' to be hit easily from the ground, no ladder needed. Bob's mix would take at least 10 times longer to apply without using proper chemical injectors in his machine, and well over four times as long to work. While Mr. Mister is "in and out" in about 90 minutes, Bob could be there all day.
After all that siding cleaning Bob will probably need at least another hour or two to clean the dirt and growth off of any sidewalks, let alone a driveway, with a "penguin waddle" waving his pressure gun from side to side in 4" passes...usually leaving tell-tale "tiger stripes". Meanwhile Mr. Mister could literally run circles around him with a 31' surface cleaner, pushing out 8 gallons of water a minute through four nozzles at a constant 2500psi...going evenly over every square inch dozens of times a second.
With all that in mind, even if you don't choose to go with Mr. Mister, at least you learned more about the process here and are able to ask questions to other contractors to help find the right one for you. All I ask is that you hire someone with similar standards, and who is licensed/insured, it will save you both time and money in the long run... it could even save your house.
...And if you see Bob, tell him not to quit his day job just yet.
Is "house wash mix" mostly bleach? In a way...yes. Bob might have Clorox's top of line bleach, but what it lacks is potency, and what he lacks is efficiency. The active working ingredient in bleach is Sodium Hypochlorite, which degrades over time. Clorox is only about 5% Sodium Hypochlorite and can sit on a shelf for months. Mr. Mister uses fresh 12.5% straight Sodium Hypochlorite, and uses a special pump/injector to apply it. The secret is in the dilution; starting with fresh 12.5% chemical a final solution of just 1% is enough to clean without harming plants or landscaping. The commercial grade pump/injector allows heights of 40' to be hit easily from the ground, no ladder needed. Bob's mix would take at least 10 times longer to apply without using proper chemical injectors in his machine, and well over four times as long to work. While Mr. Mister is "in and out" in about 90 minutes, Bob could be there all day.
After all that siding cleaning Bob will probably need at least another hour or two to clean the dirt and growth off of any sidewalks, let alone a driveway, with a "penguin waddle" waving his pressure gun from side to side in 4" passes...usually leaving tell-tale "tiger stripes". Meanwhile Mr. Mister could literally run circles around him with a 31' surface cleaner, pushing out 8 gallons of water a minute through four nozzles at a constant 2500psi...going evenly over every square inch dozens of times a second.
With all that in mind, even if you don't choose to go with Mr. Mister, at least you learned more about the process here and are able to ask questions to other contractors to help find the right one for you. All I ask is that you hire someone with similar standards, and who is licensed/insured, it will save you both time and money in the long run... it could even save your house.
...And if you see Bob, tell him not to quit his day job just yet.