After talking about it for months, maybe even years, I have finally begun the back lanai roof replacement project. The major problems I've been running into are related to it being an unpermitted owner built addition. I've been trying to repair, replace and put it back together as it was built, one piece at a time. I've just run into a major problem. The roof used the Palram Suntuf corrugated polycarbonate panels. I will be using the same type of panels for the new roof. A major problem with the previous install is that none of the recommended closure strips were used to support the panel installation. A couple of hurricanes and a few other wind storms have beaten the panels badly. So, my current problem: The length of the lanai roof where it attaches to the edge of the house's roof is 59' 5". The length of the lanai at the outboard end of it's rafters where its fascia and gutter attaches is 59' 2-1/2". It looks to have been built from L to R as the discrepancy is between the last rafter on the R and the fascia on the end of the lanai. Normally, this wouldn't an insurmountable problem except, for the corrugations in the panels and the use of the horizontal closure strips that match and hold the corrugation spacing. The end panel will require a diagonal cut along its outer edge to fit the end fascia creating problems with installing the vertical closure strips and sealing the edge. The problem appears to be that the 4x6 beam on the top of the outer wall is 2-1/2" short. They did not use the horizontal closure strips. So, they could kind'a cock the panels to allow for the difference in width top and bottom. The only cure I can see for this condition is to replace the end 4x6 with a 2-1/2" longer timber. There is a 12' borate treated 4x6 availabla at HD that could be cut down to the length needed. Other ideas?