Plan to use Ipe for backer. For someone who doesn't know what Ipe (pronounced e-pay) is. It is an extreamely dense South American hardwood almost as heavy and dense as iron wood. Costs about $1.00 for a 1/2" x 6'' x 1foot. The Ipe I have are scraps left over from a $15,000.00 deck. No! is not from my deck.