I am trying to find information about grade beams for the slab in a 3 car garage. The garage is 30'x30' and the footers and walls are in place. I know I read an article about the floor and grade beams but cannot now find it. Is there somewhere to go for detailed information about how many are needed, sizing and reinforcing needed? Appreciate any help.

Hello to all you fine people. We bought a home with a craftsman garage door opener already installed. No instruction manual or remote control. The opener is about 3 years old. We bought a universal opener and finally got it to work, but the door won't close in one continuous operation. The remote button has to be hit numerous times for the door to finally go all of the way down. It only travels a foot or two, then stops and waits for another hit on the remote. The door works fine coming up. There is a wired button on the wall and it acts the same way. The two electric eyes seem to be pointing at each other and are lit up. Any help here would be greatly appreciated. Thank you in advance for helping to get the door to go down in one operation.