HOW TO CUT SHEETROCK (WALL BOARD)
It's much easier cutting sheet rock off of a pile that is leaning up then trying to cut from a pile that is flat on the floor or trying to lay them on horses. This is how a pro would cut sheet rock.
1st I will show you how to cut a butt joint.
How To Cut A Butt Joint (A butt joint is a up and down cut, 48" x ??)
Step 1: Measure
First, hook your tape measure and measure your sheet. In this example we want to cut the board at 86". I usually stick my utility knife in the rock and leave it there. Then I slide the T-square along the rock until it meets the knife.
Step 2: Score
Now hold the top of the T-square tight with your left hand. Using your left foot, pinch the edge of the square tight against the rock. Now using your right hand and your utility knife, score the rock from the floor up. If you want you can come all the way up until you hit your square. If you run your knife up and across the square it will dull your blade in a hurry. I usually stop about 3/4 up and score the rest of the way from the top down.
Step 3: Snap
At the spot you just scored, fold the sheet rock towards you . Reach over the top and score the inside of the fold with your utility knife. Only score the middle area. (Up and down arrow in picture). Now snap the sheet rock back against the pile. At the same time you snap , hold the sheet tight to the pile using your foot and your left hand. Now pull with your right hand. This is hard to get from a picture but it's really not that difficult. After a little practice you will see you can do the snap in one fluid motion.
How To Cut A Rip Joint (A rip joint goes the length of the rock)
Step 1: Measure
Here we are cutting a 12" x 144" rip. Using your left hand, pinch the tape between your thumb and finger at the desired measurement. With your right hand, pinch your utility knife just under the tip of your tape measure. You should now be holding the tape 12 inches down.
Step 2: Score
Pull the blade along the sheet rock keeping your left and right hands all locked tight. Try to keep everything rigid and don't let one hand get ahead of the other. When you have the rip scored all the way across, fold the sheet rock towards you at the cut.
Step 3: Snap It
Now you have 2 options. You can reach over and score the back side or you can snap the rock back at the same time pinching it with your knee. This takes some practice, Fresh rock snaps much easier then old stuff.
If you are hanging walls that are 9 feet tall they make a special board called 54 inch, also known as "fat board". By using fat board you eliminate the 1 foot rip (also known as a bastard joint) making your job much easier to coat and finish.