I built a very large picnic table last year made exclusively out of PT 2x6s last year. Not to be outdone, my son built one of his own vision. He used PT 4X4s for the legs, rest of the lumber is white pine with water sealer.
2X10s for the top, and 2X12s for the seats, 2X6 framing members. It looks awesome.My question is regarding longevity, is this going to be a problem down the road for his picnic table regarding use of non-PT lumber? He did use water sealer on it.