Kill moss/green mold on wood shingle siding?
My parents have one corner by the kitchen door that gets green mildew - almost a moss but not as thick - growing on it. I believe they have cedar shakes, they are 35 yrs old and have been stained with solid color stain of some kind many times over the years. My dad is currently killing it with vinegar. Should he be using borax or something else? I understand bleach doesn't work, and actually makes it worse. Will vinegar do the same b/c of the water?
Is there a mildewcide that should be applied after cleaning with vinegar or borax or whatever? My mom doesn't want to have to repaint/stain but I think they will have to anyway, I know there are mildewcides that can be added (have done it to interior paint) but is there some special one for exterior stain? Thanks.