I have a 17'x7' insulated garage door and one of my torsion springs broke last night. The previous owner said that they replaced the original ones with smaller versions because that's all the store had in stock at the time. I want to get the most appropriate size for my door but I dont know what needs to be considered. What size torsion springs should I use, or how can I figure it out?
Every door based on weight has has its own very specific spring or springs. No guessing. You can take your complete old spring to an overhead door company and they will get you the correct replacement. While we are on the subject, the changing of an overhead door spring is really not a job for the home DIY guy. This is dangerous. If you have a high level mechanical aptitude, maybe; but watch the videos on YOU Tube first. And be careful.