Almost everything on this hub is concentrate, so your result depends on your dilution. Mixed too strong and you waste money and risk the surface; too weak and you conclude the product does not work. Neither is the product’s fault.
Reading a ratio
A ratio like 1:10 means one part concentrate to ten parts water. Some labels instead give a quantity per gallon — “4 oz per gallon” — which is the same idea expressed usefully, since a US gallon is 128 fluid ounces.
A few useful conversions: 1:10 is roughly 12 oz per gallon. 1:20 is about 6 oz per gallon. 1:30 is about 4 oz. 1:50 is about 2.5 oz.
Always use the label. The dilutions above are arithmetic, not recommendations — every product is different, and the figure that matters is the one on your bottle.
Strength by surface
Most concentrates give a range, and the principle for choosing within it is consistent:
- Delicate surfaces — painted wood, composite, anything you are nervous about: the weakest dilution in the range, and test first.
- Vinyl siding: mid-range. The dwell time does more than the strength.
- Concrete and masonry: the strong end, since these tolerate it.
- Heavy growth anywhere: resist going stronger than the label. Two normal applications beat one over-strength one, and are safer for the surface.
How much mixed product do you need?
A rough working figure for applying cleaner to a vertical surface is a gallon of mixed solution per 200 to 300 square feet, depending on how porous and how thirsty the surface is. Concrete soaks up considerably more than vinyl.
A worked example. A single-story wall 40 feet long and 10 feet high is 400 square feet, so roughly 1.5 to 2 gallons of mixed solution. At 1:10 that is somewhere around 20 to 26 ounces of concentrate — a fraction of a 128-ounce bottle.
Which is the useful takeaway: a gallon of concentrate goes a very long way, and the cost-per-wash of doing this properly is small.
The second dilution nobody expects
If you apply through a downstream injector, the injector itself dilutes your mix again — typically drawing something in the region of one part chemical to ten or more parts water, depending on the injector and your flow.
So your bucket mix is not what hits the wall. In practice this means mixing stronger in the bucket than the final target, and the only reliable way to calibrate it is to test on an inconspicuous area and adjust.
Applying with a pump sprayer avoids the whole problem: what you mix is what lands. That is one reason many professionals apply by sprayer and use the pressure washer only to rinse. How injectors work is in this page.
Practical mixing
Warm water dissolves concentrate better, which matters with powders and thick gels.
Water into the bucket first, then concentrate — it reduces foaming and splashing.
Mix only what you will use. Oxygenated cleaners in particular lose strength once mixed; a bucket left overnight is weaker than it was.
Label the bucket. Obvious, and worth saying once.
Dwell time beats strength, every time
If a cleaner is not working, the first thing to change is not the ratio — it is how long you leave it on. Five to ten minutes, kept wet, does more than doubling the concentration, and it will not damage anything. Re-mist if the sun is drying it.
Then the surface-specific methods: siding, decks, driveways.
