Plasterboard is showing up as something of a problem for eventual disposal because of the high levels of sulphate. In England and Wales, since the 1st of April 2009, high sulphate wastes sent to landfill must go to a ‘high sulphate monocell’ specifically designed for sulphate wastes (Check with your local waste and recycling facility).
There are, however, government initiatives afoot in the form of the Plasterboard Sustainability Action Plan to encourage industry to recycle more of the million tons a year of plasterboard waste, or alternately some suppliers have put in place their own recycling schemes, eg Lafarge.
The plasterboard industry has generally been slow to implement a recycling strategy.
Indeed the plasterboard manufacturers can hardly be said to be transparent about their policies and in the past the almost national monopolies of these companies have come into question. In 2002 the four main plasterboard manufacturers (BPB, Knauf, Lafarge and Gyproc) were given enormous fines by the EU for price fixing through a cartel extending throughout most of Europe. This gives an indication of how some of the largest materials suppliers work together and may be too entrenched in their manner of operation to want to see change
There are more eco-friendly alternatives to plasterboard such as Enviroboards and Heraklith BM but as the latter are imported from Germany they tend to be more expensive and have ecological transport costs.
The main uses of plasterboard are:
- providing fire resistance to walls and ceilings more +/-»
- creating a flat smooth surface which can be plastered or decorated directly more +/-»
- adding acoustic insulation
- adding thermal mass more +/-»
The
Building Regulations,
Approved Document B (sections B2 and B3) stipulates how much fire resistance different parts of a building require and what the Spread of Flame limitations are. It is very often possible to achieve the requirements by adding one or more layers of plasterboard.
Plasterboard is paper faced with one side being of relatively good quality so that it can take paint directly. This is the method of finish being adopted by many of the
SIPS manufacturers and by Walter Seagal self builders. The more traditional method is to hand apply two coats of plaster (undercoat of browning, top coat of finish) and then decorate. If the former method is used then joints are normally feather edged and taped and filled (or simply covered with a timber cover strip); if the traditional method is used then they are simply taped
This is a slightly controversial subject because it has been and still is somewhat difficult to quantify although upcoming software is getting better at it. Thermal mass is normally a very useful component in stabilizing temperatures in a building because excess heat goes into the walls and ceilings and is stored there until the temperature drops. What is difficult to calculate is how deep it goes into the surfaces before it starts coming out again. See
Thermal Mass. Arguably the diurnal temperature cycle is the most important one in this context and although the layer of thermal mass provided by plasterboard (and plaster) is relatively thin, it is situated in the optimum location to have the maximum effect (on the surface). For instance the total mass of plasterboard used in a two storey four bedroom timber frame house (as required for fire protection) may well be around 3 – 5 tonnes, which gives considerable thermal mass
