Install the lower panel first as this will help support the top panel during fixing. If the wallceiling junction will be squarestopped then it may be preferable to fix the top sheet first as this will form a neat edge at the top of the wall.
Measure and cut the sheet to fit around any windows or doors.
Apply glue daubs to the studs 300mm apart. Do not place glue where the edge of the sheet will be located.
Place some small off-cuts of plasterboard at intervals along the wall-floor junction and then rest the sheet on these.
Press the sheet firmly into place at the location of each glue daub.
Screw using 25mm x 6g Gib Grabber plasterboard screws along the top edge of the sheet in the tapered area on each stud, starting in the centre and working toward the ends.
Continue screwing the perimeter of the sheet with fixings 300mm apart. Do not plasterboard screw around windows and doors where glue has been placed.
Cut the top sheet to fit around any windows or doors.
Lift the top sheet into position and rest on top of the bottom sheet and attach as per the first sheet.
When fixing vertically, start at a window or door and cut the first sheet to fit so that any joins are further than 200mm from the corner of the window or door. Also ensure that joins extend a minimum of 200mm beyond the corner of the edge of the window or door.
Dealing with grooved jambs
For best practice, architraves should be used. However, if the use of grooved jambs is unavoidable remember:
Ensure that best practice has been used to install windows and doors, ie the back edge of the groove and the front face of the timber line up. The plasterboard should have 1mm to 1.5mm clearance in the groove.
Do not try to force the plasterboard into the groove.
Keep joins to a minimum.