Tapered or square edge plasterboard?

When buying plasterboard you only really have two options (apart from size and thickness). That choice is tapered edge or square edge, what’s the difference and why would you choose one over the other?

Tapered or square edge plasterboard?

If you are dry lining the walls then you want to use tapered edge so you can tape and fill the joints for a perfect finish. if you are planning on skimming the plasterboard with plaster then use straight edge as it is often cheaper.

Tapered Edge Plasterboard

As its name suggests, tapered edge plasterboard has a small taper on the edge of each board.

Straight Edge Plasterboard

Again as the name says, this plasterboard has a straight edge, no taper at all. This is the more common plasterboard and is quite often the only choice, especially in DIY stores.

Which one to use?

There is one reason tapered edge plasterboard exists, and that is dry lining. Dry lining is where your walls are never plastered and instead, the plasterboard is painted to leave your finished walls.

Tapered edge plasterboard sheets are used in this situation because you can get a much cleaner finish.

With the gap between the two sheets being tapered it actually sits below the rest of the board. This allows you to tape the joint and add some jointing compound on top. This then brings the join up to the same level as the rest of the wall, allowing for a seamless finish.

If you tried the same method with a straight edge sheet you would end up with a raised area over each join.

So why use straight edge then?

Straight edge plasterboard is cheaper, often considerably so. And if you are planning on skimming the walls with plaster anyway then there is no reason to use tapered edge. In fact if you are plastering you want a flat surface to start from so a straight edge is preferred.