A year ago Volterra Architectural Products built the largest monolithic urethane viga ever to be poured for a job in North Phoenix. This viga pole is 12 ft tall - 12" wide and a amazing 2" thick!!! It weighs 93 pounds and is hollow with a 8" cylindrical core. It can be used for interior or exterior ceilings or posts. Urethane fake or faux wood has little or no maintenance, not like real wood vigas. My neighbor built a Santa Fe style home 10 years ago and used real wood vigas and they looked beautiful for the first 6 months and then it seamed like overnight they turned brown and cracked up so much I could put my knuckles in them. They are still there and he has paid someone a very large amount to come clear coat them twice but they still look and are hammered. They continually twist and move and have cracked the stucco a few times which also had to be repaired. The cost of our faux wood viga is a little bit higher at point of purchase than the real wood viga but my story should enlighten you on the cost savings of our wood viga over a period time. If you are not familiar with high density polyurethane foam (HDF) - I lived and framed homes in Santa Fe New Mexico 18 years ago and most of the huge custom, boxy, cut up, parapet everywhere pueblo style flat roof homes..... use urethane foam to waterproof there roofs.... which is the best way to waterproof a roof and it does add a 4.7 R-value per inch to the roof. The foam we use to build all of our architectural parts is the same polyurethane other than we use 8-21 lbs per ft. material whereas the roofing industry uses 4 lb per ft. foam.