Fumigation is a lengthy process if you hire professionals then usually it takes 24 hours to 72 hours. But if you try to do it by yourself then things can get worst and the time will be 1 week to complete this process. My suggestion is to hire a professional and let them do this job. Before the fumigation starts you have to clean up your house and remove every living thing from it like plants and pets. Must remove the food from the house or take it into the fridge with tight packing. The professionals will guide you about everything you have to do before the fumigation service starts.