Avoiding joints is near impossible when constructing walls or ceilings with plasterboard. What you can do, however, is choose the right type for your project. Plasterboard panels have two edge types: tapered and square. Now you may wonder whether one is better than the other. Should you use tapered or square edge plasterboard?
The choice between tapered and square edge plasterboard is dictated by the application. Tapered edge plasterboard is commonly used for walls. Its narrower edge profile makes joining or skimming easier. Square edge plasterboard is a more common choice for ceilings or textured finish applications, as the seams between the sheets are less visible.
Tapered vs. Square Edge Plasterboard
Tapered and square edge plasterboard exist because they serve different purposes. Some DIYers may believe that one is better than the other. However, you should choose the plasterboard type based on the application.
Using Tapered Edge Plasterboard
|Ideal for constructing walls||Slightly more expensive than square edge plasterboard|
|No skimming required||Unsuitable for corner installation|
|Better looking result|
When buying plasterboard, it is important to understand that the only difference between tapered and square edge panels is the edge. You can find standard and speciality plasterboard types in both categories, and both categories include panels of various thicknesses.
That said, tapered edge plasterboard is a type of plasterboard created specifically for walls. In a flat wall installation (not a corner), the tapered edges meet and create a recessed triangle that you can fill with joint compound. The compound increases the plasterboard thickness in the joint area, allowing you to obtain an even surface without skimming.
Another advantage of the “valley” is that you can use fiberglass mesh or other types of stronger joint tape when sealing the seam. This is a huge advantage in applications that require more strength, such as installing plasterboard in the kitchen or bathroom.
Using fiberglass mesh tape would not be possible with square edge plasterboard because the tape is too thick and would result in bulges.
Tapered edge plasterboard is the best choice for walls regardless of the desired finish. Not only will the joints become invisible under paint, but the even surface also provides a sounder background for tiles.
Because the tapered edge design requires a specialised manufacturing process, this plasterboard type is slightly more expensive than the square edge variety. However, the price difference is negligible.
Another thing to keep in mind is that tapered edge plasterboard is only suitable for flat wall installations. When used in corners, it will produce corners that are not perfectly 90 degrees.
Using Square Edge Plasterboard
|Ideal for constructing ceilings||Requires skimming|
|Cheaper than tapered edge plasterboard||Joints may remain visible|
|Easier to install by beginners|
Square edge plasterboard refers to sheets that have straight edges. The panel maintains the same thickness throughout, and when two panels meet, they create the so-called butt joint (called this way because the two plasterboard sheets are butted up against one another).
Square edge plasterboard can be used for all applications. However, it is near impossible to maintain the wall surface even when sealing the joints. The joint compound and tape can easily create a bulge on the surface.
For this reason, skimming is always necessary when using square edge plasterboard (unless there are no joints, in which case you can skip this step).
Choosing the right drywall tape and joint compound is also crucial to avoid adding unnecessary thickness. Generally, you’ll have to use ordinary paper tape or another type of thin material, which may not be ideal in all circumstances.
That said, square edge plasterboard is a better choice for ceilings because the panels are easier to seam together when working overhead. Typically, you should board new ceilings with 12.5mm sheets and use 9.5mm panels for design features or suspended ceilings.
Why Choose Straight Edge?
A quick search online shows that many DIYers prefer straight-edge plasterboard. However, you should know that choosing the square over the tapered edge is exactly that – preference. Instead of wondering why to choose a straight edge, you should rather learn when to use tapered or square edge plasterboard.
As mentioned above, you should use square edge plasterboard for ceilings and tapered edge plasterboard for the walls.
While you can use straight edge for walls, too, remember that this choice is only suitable if you are planning on skimming the boards with plaster. For all dry lining installations (no skimming), only the tapered joint will allow you to fill it for a perfect finish.
The squared vs. tapered edge plasterboard types often cause endless debates among DIYers and contractors. Some even claim that the tapered variety should only be used for dry lining. However, the truth is that you should use tapered edge plasterboard whenever you want to get a cleaner, better-looking finish. We hope this guide has taught you what tapered edge plasterboard is used for and when to choose square edge panels instead.