[Bud Cline]

Have no idea what you are trying to say or do.

 

[havalife]

You must mean Joist. Take your time and use a sharp knife, or cut along the joist and use a 2x for backing.

 

[oh'mike]

Often adding a 2x4 along side the joist is the easiest and fastest method--that way you can just saw off the old drywall alongside of the joist.

If you have the patience and a steady hand,you can cut the drywall right down the center of the joist.

 

[MikeKy55]

If you have the patience and a steady hand,you can cut the drywall right down the center of the joist.

I did it this way when I put a sheet up and the edge wasn't dead center on the joist. I took a 4 foot level and drew a line across the edge to be cut and then used a utility knife with a new blade.

 

[bjbatlanta]

Take a nail and find the edge of the joist, then measure back 3/4" to the center on both ends of your 4' sheet. Draw the line and you'll have the center of the joist all the way. Or oh'mike's method is perfectly acceptable. Just be sure to get the new piece of wood flush with the old so the pieces line up....