Rules of thumb (verify for your surface)
- Vinyl house wash: ~1% SH at the surface
- Roofs (asphalt shingle): 2–3% batch-mixed, applied soft
- Concrete pre/post-treat: 2–3%, hotter for heavy organic staining
- Downstreaming from 12.5% stock through a 2.1 GPM injector lands near 1% — exactly why fresh stock matters. Ours is batch-dated.