Columbia offers the widest range of high quality Flat Boxes in the world. From our 5.5” specialty box to our 14” they are all star performers. Well-built and fine-tuned to offer great flat joints for years. We have been being told for years that our boxes are the smoothest finishing and easiest to push. We are very proud to get this feedback and will make sure that every Flat Box we make exceeds your expectations. You can find Columbia drywall flat boxes both in store & online at Master Building Materials in 7″, 8″, 10″, 12″ & 14″.
