The 2 x 4 " pcs were added (bolted) to the roofing sections we constructed in the driveway. They are the white vertical pcs about 18 " long holding the east side of the roof up. Note rounded bottom cut out of The "risers" to fit around the pipe framework of the fencing.. Also see the pallates used as part of some scaffolding helpful in working on roof. [ If used, be sure lumber is strong enough and fastened together solidly enough to support your wweight.... I didn't do that. ] OUCH ... Only hurt for a little while.