Plaster Board

What Is Plaster Board, How Is It Made, How Much Does It Cost, Is It Better Than Wet Plastering

A plaster board consists of layers of paper that has been bonded to gypsum plastered core and is used mainly in the construction of walls. A plaster board is also known as gypsum board or wallboard. Plaster boards are used in home construction in some parts of the UK and US and in certain conditions, it is also preferred to wet plastering.

Making  Plaster Board

A plaster board panel consists primarily of gypsum plaster, which is known to be a semi-hydrous form of CaSO4 or calcium sulphate. Raw gypsum has the chemical formula of CaSO4·2 H2O and is obtained through flue gas desulfurization and needs to be calcined before it can be used. In order to create the plaster board, gypsum is first mixed with paper or fibreglass or both. It is then mixed with foaming agent, plasticizer, potash that acts as an accelerator, starch or any other chelate that acts as a retarder, EDTA, water, different types of additives that increases fire resistance and mildew, and wax emulsion to enhance lower water absorption. The wet gypsum mixture is then sandwiched between two sheets of fibreglass mats or heavy paper. It is then kept in the drying chamber and once it is dried the fibreglass mats-gypsum sandwich will become strong and rigid enough to be used as a building material.

According to industry standards, a plaster board is made using two types of edge treatments - the tapered edge treatment and straight edge treatment. In the tapered edge treatment, the long edge of a board is tapered using a wide bevel in order to allow jointing materials to get a finished flush. In the straight edge treatment, the edge thickness is worked upon in such a way that it is the same as at the middle of the board.

Plaster Board Sizes and Prices

A plaster board is available in a variety of sizes to choose from.

UK and Europe

The plaster board manufactured in the UK and Europe are available in metric sizes and the most common sizes are the corollaries of the old imperial sizes. The different sizes available include:

The most commonly available plaster board thickness is 12.5mm for walls and 9.5mm for ceilings. One of the new sizes available for plaster board thickness is 15mm.

Here's an insight into the cost of plaster board sizes:

USA and Canada

Plaster board panels are available in the US and Canada with 4 ft (1219 mm) width and different lengths. In some of the more commercial applications, plaster boards of up to 16 ft (4.9 m) width are also used. The cost of different types of plaster board in the US and Canada include:

Wet Plastering or Plaster Board?

Use of wet plastering or the plaster board depends on the building construction requirement.

Wet plaster finish has been a tradition in homes in the UK although the constituents or materials used in the plaster has varied over centuries. Over the years, plaster has constituted primarily clay, gypsum coating, lime renders, cement and even Artex. There are a few problems with wet plastering though and this is related to its application. Wet plastering can only be done by a skilled plastered. Once the plastering has been done, it has to dry out. Many a times, after drying up, it has shown movement cracks and not to mention there is the problem of shrinkage as well. Apart from this, if wet plastering has not been done by a skilled plasterer then the finish will be bad and it will not be durable.

Due to the disadvantages of using wet plastering, more and more people have started to use plaster board in their homes and this phenomenon has risen only in the last 30 years. Today there is an ever increasing popularity for using plasterboard for walls as it can be put up quickly and can be easily finished using sandpaper, tape, and paint.

"In my experience of owning 4 new homes in the last 25 years, modern homes tend to use a combination of plasterboard covered by a thin finishing layer of plaster. This gives the best finish as the thin plaster layer dries reasonably quickly and it gives a good smooth finish. You don't mention this technique in your article."

P Hill