Up to 45 muinits depending what you are trying to remove
Thank You.
It's just very heavy algae. It's killing 90% on the first pass but I'm getting streaks at the lower part of the walls where it seems to be drying before I rinse it.
Work from the bottom up when applying the mix, that way you don’t get missed areas nor streaks.
If you work from top down, it’s fine, but it will sometimes mean that the mix neutralises and weakens as it runs down the render.
If you’re using a high powered, high flow machine, wirking top down is fine, but lower flow rates and a spray tip, do the opposite.
I’ve also had times where I haven’t rinsed at all. I had a job where the render was so incredibly bad in just a few spots, I did the job, then sprayed some mix on those bad areas, went home, customer emailed me saying it had completely gone and was absolutely amazed. Cab take a couple of hours to ‘bleach’ the black spot/black algae.