We have a CMU (concrete masonry unit, or more commonly, cement block) wall surrounding our house in Los Angeles that was painted grey. We will be installing horizontal wood slats over vertical pressure treated 2x4 studs attached to the CMU with Simpson Titen stainless steel screws. The face of the wood slats with be narrow (about 2 inches) with a 1 inch gap between each slat. They will be stained ebony with either Penofin or Timber Pro semitransparent stain.

We'd like to paint the CMU darker so you don't see the grey behind the fence. The paint on the CMU has held up pretty well; no peeling or flaking. I've read about power washing, then sealing then primer then finish coats... that seems like a lot of effort for something that will be mostly concealed. What is the best (and efficient) way to repaint given that you won't see much of the CMU once the fence goes up? Thanks in advance for your help.

This post was edited by ElGrecus on Wed, Jan 29, 14 at 2:45