Keystone Contracting Group Inc Share: Roofing Contractors Keystone Contracting Group Inc Visit Website 3727 Greenbriar Dr., Ste. 400 Stafford, TX 77477 (832) 557-5326 Hours: 8:00 am to 5:00 pm M-F About Map About Keystone Contracting Group, Inc. is a locally owned and operated residential and commercial roofing contractor based in Stafford, TX with over 35 years experience in the roofing industry.