Can you even get a hold of them if your roof starts to leak? Roofing by J.M.J is Knoxville's Roofing Contractor since 1986, we will be here when you need us! Roofing by J.M.J has factory trained and certified commercial installers to handle all of your commercial roofing needs. Roofing by J.M.J has the manpower and equipment to get the job done fast