During drywall installation, the two types of side-by-side joints you encounter are known as butt joints and bevel joints. They derive their names from the way the sheets of drywall fit together. Butt joints are butted together short end to short end. Bevel joints, also called recessed joints, fit together along the long end of the drywall. On either long end is a finished recess or bevel, a preformed indentation that runs the length. Of the two, butt joints are more difficult to work with during the taping and mudding process. When assembling this type of joint, you are faced with the same challenge as when joining beveled edges. The fact is you are screwing into the very edge of the drywall, so the proper placement of the sheet helps to ensure precision assembly.
How Drywall is Attached to Studs
For drywall sheets on a flat plane such as a wall or ceiling, you know there are two basic joints: butt joints and bevel joints. Whenever two sheets meet along a wall, they must both be secured to the same stud. One of the biggest mistakes to make when hanging drywall is to let one end of a sheet sit unsupported up against another sheet. Studs usually are placed every 16 inches on center. Since drywall is 48 inches wide, one sheet should span 3 studs vertically or twice that horizontally. This assumes that the studs are well framed. If not, there may be some issue with the placement that will require adjustment.
Studs are 1½ inches wide, meaning that each sheet of drywall at a joint is allotted ¾ inch. That is not a large amount of space to set screws which is why the joints need to run evenly up the stud. Once you assemble one joint, you have to be sure the next joint down sits over a stud. If not, you have to cut the drywall to compensate.
Assembling Butt Joints
What makes butt joints more difficult is the finishing. Their assembly is virtually the same as with bevel joints. In both cases, you have to insert screws within ¾ inch from the edge of the drywall and make sure you sink it into the stud. When assembling butt joints, straighten the first sheet of drywall in position and fasten it to the stud. Make absolutely sure you leave half of the stud exposed for the adjacent sheet. Take your second sheet and butt it up against the already-hung sheet, short end to short end. When hanging drywall, always fasten from the middle out. Move to the middle of the sheet, and with your hand firmly holding the butt ends together, set several screws in the middle of the drywall. Then move the outside stud. If the sheet was held in place properly, given a well-framed stud, the butt joint will be precise.
It may help to measure where the studs will fall and snap a chalk line along the drywall indicating exactly where to set the screws. This is especially important if the studs are off in any way. Forming a good butt joint hinges on your ability to hold the drywall tightly up against the adjacent sheet and solidly set screws in the middle, working your way to the edge of the drywall to secure the joint.