I found a great price on a granite fireplace surround. It wasn't designed in the load calculations of my house when I designed and built it, but it was such a deal I couldn't pass it up. It weighs around 4,000 lbs. It is about 5 1/2 feet long and 16 inches deep and would be sitting on 3/4 inch advantech. I have on hand and would like to use 2 lvl's , 1 3/4 X 16 inches deep spaning 12-14 feet with 4 inch poles at either end of the lvl's for support. These lvl's would be placed between two 16 inch open web truses. I can also add two 2X12's for extra support.
Thoughts?
Or can anyone tell me where I can find the load calculations of lvl's.