I bought my house about a year ago and it has this dead smell in the garage... I had the odor finders come out 2 x's and they could not find anything in the walls or the attic... they sprayed the walls both times but the odor still exits... I painted the sheetrock and that did not help so I got concrete cleaner and cleaned the garage floor and pressure washed it then primed and painted the concrete... still to no avail... I still have this terrible odor... can someone please give me some suggestions... have ran out of ideas... smells of something dead...

Sounds like a dead mouse or rat in the wall or ceiling. Sure it's not mold? Is it stronger in one area? Are the walls all finished? Hate to say it, but I'd tear down the sheet rock and re-do it, after I looked for mold and dead rodents.

A dead mouse smell will go away in 10-14 days, dead rat in 14-20 days. If you continue to have a dead smell for a very long time I thinks it is not a dead animal. Are the walls finished, with what?