Softwash dilution calculator
How much stock hypochlorite and how much water to make a tank at the strength you want.
To fill a 100L tank at 2%
40 L
stock chemical
60 L
water
Working strengths people use
| Render and painted walls | 1–2% |
| Roof tiles | 2–3% |
| Patios and paving | 1–3% |
Ranges, not instructions. Surface, soiling, dwell time, temperature and what the substrate will tolerate all move them.
The arithmetic is exact. The strength is your call. Test a small, hidden area first, protect planting, follow the manufacturer's guidance and wear the right PPE. Hypochlorite damages fabric, metal and plants, and no calculator knows what you're standing in front of.
This is one small piece of MossyKit
MossyKit runs the whole job for UK exterior cleaners — an enquiry form for your website, measuring and pricing off your own rates, the quote written for you, customers picking their own date, then invoices, card payments and chasing.