This joint needs to be flush and smooth in order for the tile or other wall covering to be installed correctly and to create a professional finished appearance.
Cement board meets drywall at outside corner.
If you have outside corners to do then you may decide to just get the 4 inch mesh tape only and use it anywhere you.
It is a long strip of corner piece made out of aluminum paper or vinyl and is installed over a drywall corner giving the drywall a finished and professionally done look.
Cement board is much heavier and harder to work with than drywall but it is almost completely waterproof.
How to make the transition from cement board to greenboard.
They make 4 inch alkali resistant mesh tape and this stuff works great.
The walls were easier because i had tile wrapping around the corner so i just taped and thinset those and tiled overtop.
The shower ceiling is hardibacker and the wall outside the shower is drywall.
It s hard to get the tape to fold over the corner and stay long enough for the thinset to set up.
In this video i will show you how to prep a corner bead and where cement board and sheet rock meet.
Greenboard is a moisture resistant drywall product designed for use in areas of high humidity and where occasional incidental contact.
At some point along the wall the cement backer board will meet with the drywall used in the rest of the room.
Cement board is also used in the walls of showers and bath surrounds where there s going to be a lot of moisture.
Outside corners can be difficult with 2 inch mesh tape.
Durock is a type of cement board that is water and moisture resistant.
Drywall is pressed gypsum which is used in modern walls as the surface material.
These areas are pretty simple to prep but there are a few.