This roof in Columbia TN was originally an old mixed smooth and gravel Built-Up Roof that had been neglected for many years. The new owners bought the building with plans to renovate and create a new office space. When it came time to keep the water outside of the building, TLC got brought in to hear their options. We ended up tearing out the smooth BUR and replacing with TPO. Wanting the most economical solution, we installed spray foam over the gravel BUR topped with a silicone coating. Both roofs ended up with a 20 year warranty.