Dry lining plasterboard with tapered edges may be used without applying a skim coat of finish plaster. By taping and filing the joints a smooth surface ready for decoration can be achieved. In this article we demonstrate how to cut and fix the plasterboard, tape the tapered joints, then apply jointing compound which can be sanded smooth prior to painting.
The dry lining plasterboard used for this generally comes in sheets measuring 2400mm x 1200mm and has a wide taper along the longest edge. Other sizes are also available. The timbers used for the studwork are generally spaced at 400mm centres. On walls, the boards are fixed so that the long paper edges run along the centre line of the vertical timber studs. So, on a wall 4m long, you can see that you’ll have 3 boards and a 400mm wide rip for the last piece.
1. Before positioning the board, measure the position of the studs and mark these on the board using a pencil and straight edge.
2. Align your first board ensuring that the long edge is aligned centrally along the upright timber stud. Use a board lifter to push the boards up to the ceiling edge while you make the first few fixings. A board lifter is a simple pivoting mechanism which slots under the board allowing you to lift it by pushing down with your foot.
3. Fix the board to the studs using drywall screws. These have a sharp point and quick drive threads making it easy to fix the plasterboard quite quickly.
Boards used to be fixed with galvanised clout nails but screws offer superior grip and fixing.
4. Drive the screws in using a cordless screwdriver / driil. They should be driven in so that they are just below the surface.
5. If you have a torque setting on your screwdriver, use a low setting and slow speed so that the screws don’t get driven right through the board.
6. Screws should be fixed at 300mm centres along all the timber studs. Where screws are fixed at edges, the fixing should be no closer than 10mm from the edge of the board.
7. Continue fixing full size sheets of plaster board in this way, butting the joints along the vertical studs as you go. The last section may need to be cut down from a full sheet.
8. To cut this board, lay it on a clean flat section of floor. Measure and mark the required width from the long edge of the correct side of the board at regular intervals then join the marks using a straight edge and pencil.
9. Lay a steel straight edge along this line and use a sharp craft knife to cut into the surface. You don’t need to cut deep – just enough to cut the paper surface and a little way into the plaster.
10. Carefully lift the board and snap it back from the cut line. This will neatly break the board leaving only the paper on the underside connecting the two pieces.
11. From the underside, run a sharp craft knife through the paper to finish the cut. Remember boards are quite fragile and will easily break – so handle them carefully.
12. Align this section of plasterboard carefully in position and fix as before.
13. To cut out a right angle section of a board, for example where it fits round the top of a door opening, you will need to make two cuts. Clearly you cannot snap in both directions. Measure the shape of the cut out carefully and transfer these measurements to the board. Mark them with a straight edge and pencil.
14. Cut the shorter of the two lines with a saw just as far as the point where the two lines join. A standard saw will cut quickly and easily through plasterboard. Cut from the face of the plasterboard to give a neat finish.
15. You’ll notice that the underside will be a little more ragged. This can easily be tidied if needs be by running a blade edge backwards along the cut.
16. The other line can now be cut as before and snapped back.
17. Once the cut has been snapped back all that remains is to cut the paper on the back edge to release the off cut.
18. To make cut outs within the dry lining plasterboard you will need to use a pad saw. Examples of such cut outs include existing socket boxes for electrical outlets.
19. Carefully measure the position of the box from the end and the edge of the board.
20.Transfer these measurements to the face of the board and mark with a pencil.
21. Using the pad saw, cut around the perimeter of the box outline. Hold the pad saw at a slight angle so that the back of the opening is slightly larger than the front. This extra clearance will make it easier to align the board.