difference between structural pressure treated lumber & just reg.
what is the difference, if any, between structural pressure treated lumber and regular pressure treated lumber? i know the structurual PT has those little slits or lines on it and the regular does not. At lowes they sell both kinds, very little in price difference, but is the structural PT that much "stronger" or has more chemicals during the PT process? i'll be making a deck roof made out of wood and those slits are unslightly. you can see them on the posts and rafters. could i get away with just using regular PT lumber? There will be no ground contact and I'll be using a ledger board attached to the house frame work.