I need to spray bleach onto a metal shed to get moss off it, but my two pump sprayers, one for staining with paint, and the other for insecticide both say not to use the sprayer for caustics like bleach. Why not? It might damage the hose, etc...?? Shouldn't diluted bleach (1:1) be ok? Beer 4U2

I own a 3 year old house in NE Massachusetts whose window and door trim is already rotting out. The trim in question is finger jointed pine (man, I hate that stuff!!) and must have been primed and painted with latex. I'm replacing the window trim (brick molding) with Apex/PVC stuff. I need to replace some 1" x 5" and 1" x 8" garage door trim. I'm leaning towards using cedar, priming it with oil based primer, and then painting it with latex. I plan to prime and paint the lower ends of the boards where they contact the concrete and probably the backsides of the boards several feet off the ground to prevent water from wicking up the grain of the wood. Do I even need to bother with oil based primer if I'm using cedar? Or, should I do the oil based primer and top coat with oil based paint as well? I'd like to do this right, just once.