Popping sounds around the outside walls can sometimes be a side effect of modern truss construction. The pre-load on a truss can set up a situation for transferring loads with such things as temperature changes and humidity. If the popping seems to be coming from the outside, that's where I'd start looking for the cause. If the popping seems to be coming from the floor, especially from the outside walls, You might check the piers and their relationship to the girder beams. Steel shims sometimes work their way out, and sometimes, get crushed into the bottom of the girder. The result is settling of the walls inside, doors that won't shut, floors out of level and strange behavior where the joists meet the outer band joist.
One more thing, Sorry, I get excited sometimes, Check your bath exhaust fans. They move so much moisture into the attic when they're not vented properly.
Tom in KY, former superintendent for a company riddled with warranty issues.