We are needing to renovate the 2-car garage (ie. the wife agrees ), and the first thing on the list is the drywall ceiling and three walls (two interior and one exterior sided). So I am exploring the possibilities. A coworker has a friend who installed an exterior siding material called "HardyPlank", with the lap and groove planking on the walls and the flat boarding on the ceiling. He said it looked great painted. Price and installation was twice the best quality sheetrock, but it will last forever, being made for outside conditions. Another advise was exterior-quality luan plywood, which supposedly can be nailed over the existing old drywall without warping or moisture issues arising. We want the garage walls to be good looking and durable, obviously, and then tackle the floor and cabinets, etc. Any advice or suggestions on the best value would be appreciated. Thanx in advance. PS> Home Depot has moisture/mildew resistant for $9.69 a 4'x8' sheet, while construction quality was half that at $4.99 a sheet.