Philip1993
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- Jul 5, 2007
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BigNick73 said:best house wash is a bleach mix 1 part bleach to 3-6 parts water depending on how bad the mildew and crap is use a garden sprayer to apply and rinse off with a water hose.
I ran a PW company for 3 years. The base of most professional house wash mixes is 0.75-1.00% bleach (on the wall). 1:3 (1.34%) is a bit too strong (unless you are buying dollar store bleach) and you risk killing plants and chalking siding. Add a good bleach stable surfactant and you can clean 95% of what you need with a 0.75% mix. Use a proper house wash formula (about 7 components, some not available at retail), and you can clean any house at 0.5-0.75% bleach.
One other note for the DIY house washers listening. Nick is dead on about cleaning a house at garden hose pressures. Ignore all the BS the guy at home depot tells you about needing 6 billion psi to "blast away the crud". That's the language of the ignorant. Pro's use use 3000 psi machines to clean 50ft gables from the safety of the ground. The actual working pressure at the surface is typically less than 100psi. Your 3.0 gpm machine (we use 6+ gpm) won't throw that distance anyway, so the difference between 2500-3500 psi is negligible to a homeowner.
One last note: The box box stores LOVE to print big numbers and state that "Cleaning Units" = pressure * volume. For those few jobs that require high pressure (i.e. heavy grease removal), cleaning efficiency is better approximated as volume^2 * pressure * water temp. Plug that into the HD brochure and see how they compare.