I have been here since 1998. When I moved in, my whole house was nasty from knee level down with this nasty looking green moss growing on the brick. In the front (which faces south) when it really gets going you can see a silhouette of evergreen plants, like the PO had the whole front of the house lined with them and that part of the house itself was blocked from the sun. You can tell exactly how tall they were and how they were spaced. I power wash this at least once a year, (when I have a power washer that is) I hit it 2-3 times usually once in spring summer and sometimes fall. That keeps it to a minimum, but it still comes back. and on the north side it seems to come back heavier and faster than the previous time.
The north side and west side of the house is worse. It always comes back faster and heavier than the front,
I have power washed it, steam cleaned it, (seems to stay gone a little longer but still returns)
tried a bleach soak down after power washing, several times, once I tried vinegar instead as I was told that would kill it...
I know brick is porous, but I need something that will soak in and actually kill this crap.
Last year I didn't get to power wash as my machine had gotten stolen over the previous winter, It looks real bad this year.
On the front, my gutters do leak between the gutters and the fascia, and I have a 6-8" tall raised flower bed, some of that could be dirt splashed up after a hard rain, but not all of it. On the back though it is definitely all moss.... When I just use the garden hose on teh front and rinse that off then you see the moss behind that. at the back of the house I have grass growing all the way up to the back wall of the house. I want to get some lime and spread from the house out about 3' all the way around.
Any ideas on something I could apply to the brick to kill this? Would I apply it before I power wash and let it soak a few days or like I usually don power wash and then apply?