Where plasterboard meets it forms an indentation which can be filled in with joint filler to give a perfect flat-wall finish. There are five main stages to taping and jointing.
After the joint filler has been applied, a paper tape is bedded in. This is a vital part of the process, if done incorrectly you may get cracking, or the tape can bubble and cause problems with later coats and the overall finish.
Bed the tape spreading joint filler evenly over the join, take the tape and press it into place at the top or the end of the joint. Using a trowel or filler knife, push the tape in firmly and removed all excess filler.
Next a layer of joint cement goes in to blend the joints into the wall and cover the tape. Care must be taken not to overfill the joint, as this would result in a bump which will need to be rubbed down once dry. At this stage fill in the screw heads too.
The topcoat is a finer coat. Using a trowel or filler knife, spread joint cement over the joint, ‘feathering’ it out beyond the previous coat. The better the application of the filler, the easier it is to rub down.
Use a sanding block to rub down the filler to achieve a smooth surface. A further coat of joint cement can be added to isolated spots where necessary.
Once all the filler is rubbed down it is time to apply a coat of sealer to the entire plasterboard surface. The use of a sealer is always recommended as it gives an even adhesion ready for the application of paint. The jointed areas are now ready for decorating