What is SH mix ratio?
SH mix ratio is the concentration of sodium hypochlorite (liquid bleach) mixed with water, expressed as a percentage or ratio, used to clean building surfaces without high pressure.
The SH mix ratio refers to the proportion of sodium hypochlorite (also called liquid bleach or pool shock) diluted with water for soft washing applications. Ratios are typically expressed as percentages, such as 10:1 or 12.5%, meaning the volume of SH to total solution or the strength of the mixture used on a job site.
Different surfaces require different mix ratios because of variations in how quickly the bleach will break down organic growth and how much the material can tolerate chemical exposure. Vinyl siding, wood, and painted surfaces often need lower concentrations (around 10-15% SH) to avoid damage or discoloration. Roof cleaning, particularly on asphalt shingles or clay tiles, may use stronger ratios (20-30% SH) because the protective coating needs more aggressive treatment. Concrete and masonry typically fall somewhere in the middle, depending on the age and condition of the surface.
Technicians and business owners in Columbia adjust ratios based on local water hardness, weather conditions, the type and age of biological growth, and dwell time. A weaker mix may require longer contact time but reduces risk of harm to delicate surfaces. Stronger mixes work faster but demand more skill to apply safely and more care in rinsing to prevent etching or bleach spots.
Understanding SH mix ratio is central to soft washing because the right concentration balances cleaning power against surface safety, equipment life, and job efficiency. Many roof soft washing providers in the area rely on precise ratio control to deliver consistent results without warranty issues or callbacks.