They are sold as chink-less log homes, but over time they will require caulk. It sounds like it is a kit style home that is milled and fit together with a tongue and grove system. DO NOT use true chinking. It should be done with a caulk made for log homes like Energy Seal. You really would be ahead of the game just to do it from the start. It definitely would make a difference in your heating and cooling bill. Call Mike at 866-670-3020 for help.