Normally, just pressure washer without chemical would remove this. I’m at a loss. I’m sure this is newbie material but any advice on chemicals to use or what the stain is would be appreciated. Thanks.
Oops thought i seen oxidation running down from the roof…
You got a closeup pic? Hard to tell what’s on from the one you posted.
I zoomed in and it appears to be very light mould.
Where I live, there are three main moulds that I deal with.
Green - early stages, very easy to remove.
Black - the green turns black after a while and requires more chemical, but rarely pressure.
Actual growth - such as lichen and there’s a red/orange build up one too, it’s raised and takes much, much more chemical and pressure to remove.
What I see is green - very easy to remove with SH/Sodium Hypochlorite/Bleach and some soap of your choice.
The dwell time will be minimal and it would probably be gone by the time you reached the end of the wall.
I will be trying out SH today. Here are some more pics of the wall.
Should below freezing temps (25-30 F) be a concern when using SH?
Just use a higher concentration and longer dwell time
If I go 1 part SH to 4 parts water, is that a decent start or even higher concentration?
I don’t know what you are applying with. When it is before 30 we ds straight SH