If you intend to keep CB or electronics in a shed make sure it is insulated with AirTec or something like it as this kind of stuff does not like a slightly damp enviroment. I totally had to rebuild and replace boards on a Kenwood 830 once and used to build ATU's and other related projects for radio in a shed. I insulated the shed I built a couple of years ago and since then my tools do not get surface rust etc on them link to AirTec
YBS AirTec Double Insulation 1.2 x 25m - Toolstation
YBS AirTec Double Insulation 1.2 x 25m - Toolstation