house washing
I have been in the business over ten years, i have always used the same method, and will continue to do so. i am in the pressure washing business, not the bleach and rinse business. So in my opinion, some of the work is done by the chemical, but most of it is done by the operator, and i do use my ladder and extension wands to get those high areas, dormers etc. i have always used household bleach, dollar store bleach is 5 to 6%, ($1.00 per gallon) and even with this i can dilute it (3 gal bleach to 2 gal water) prior to going through my injector. i spray the bleach on with a 40 dgree soap tip, when the algae starts turning brown (2-3 mins), i then soap it down with a detergent that i also use on trucks. the detergent breaks the algae, dirt and chalk down. when i rinse, i use a 40 degree tip and unlike most competitors in my area, i actually pressure wash the siding, one board at a time. the pressure removes the dirt/algae residue and chalkiness on the siding. I brush windows and do a light rinse on them, this is very pleasing to the customer. on the stubborn black gutter stains i use the same detergent straight and at times i will brush the gutters to whiten them up. the same detergent also works good on getting mud off foundations and cleans decks. most of my customers are repeats and referals, and more than one has told me, " the last guy that washed my house didn't spend near as much time as you, and they never used a ladder or brush" I get the most comments about windows being clean and not streaked.
I keep all my other chemicals in 55 gallon drums, but the shelf life on bleach is not great, so i just prefer the by the gallon approach on it.. also I have seen some of the stronger bleach solutions bleach out painted siding and stained decks, and killed grass.
what i would like to find is a product to spray on the siding to make it last longer before the alge starts again.
just my 2 cents.
Jeff G