I have just replaced the 2x4 plate under the garage walls with dimensional 2x4 plastic lumber. I thought that might fix the "tilt" as the plate on one side of the garage was more rotted than on the other. The building still tilts to one side and the door opening is not square so the door won't fit properly. I can push the walls out a bit to make the opening wider but I would rather make the building straight up and down. If it were the closed end that was skewed I could cross brace it with a long diagonal member. That would not be useful at the open end. There is an lean-to carport supported by posts on one side and by the garage roof on the other. My guess is that the lean-to roof might be pushing the main garage off vertical. Is that reasonable? How can I make everything square? Do I have to remove the lean-to from the garage roof? Is there a way to hold the garage straight internally with the lean to in place?
Answer:
If the lean-to is properly supported along the back, there should be no problem with everything being plumb. I have a feeling the posts supporting the outside end of your lean-to roof are flexing a bit and that will certainly have a negative impact on the garage. You might try getting everything plumb and then filling in part of the lean-to gable (front and back) with 7/16" aspenite and then applying siding. There is nothing like the strength of angles to ensure structural integrity.