My pergola is alumimum and my patio is stamped concrete. We do not want to damage the patio so we are trying to avoid drilling into it to hold the columns, any other suggestions?
unless you think you will be moving it, drilling small holes for a tap-con screw will be barely noticable. put a squirt of caulk in the hole before you run the tap con in , and a small bead around the flange after you mount the pergola…