Plaster boards are a sandwich of paper and gypsum that are commonly used as a finishing board for walls and ceilings. They are then skimmed with gypsum / thistle plaster for a really fine finish. The final smooth and flat finish is suitable for a modern home but it can take away from the natural flow and rustic finish in older properties. It can also hide a multitude of sins (see post on dry lining). So we are always keen to stress that plaster boards on walls in older houses should ring serious alarm bells. However they do have a place on ceilings as there is less to hide on ceilings (apart from artex of course). Plasterboards are now also readily recyclable through municipal site, so their eco-credentials are improving. However are there alternatives?
There are a few options:
1. Do not use plasterboard – just use a plaster over the walls, ideally this would be lime or clay plaster dependent on the type, style and requirements of the wall and your preferred finish. Lime plaster or hemp/lime give a breathable finish and allow you to preserve the natural idiosyncrasies of your wall, They also give you improved insulation values. This process takes longer and hence costs more, but potential problematic issues around airtightness and breathability are negated.
2. Use a woodwool board. These are boards that come in various thicknesses that can be plastered directly onto. They are made from wood and a binder (normally magnesium silicates). They have good acoustic properties and have a good key for plasters, however you need to be careful around the joints – these need scrim to stop cracking and some would advocate using a mesh over the whole of the wall / ceiling.
3. Use a woodfibre insulation board. These are finer insulation boards that provide insulation (acoustic and thermal) for internal walls. They are designed to have good compressive strength, but are of course deeper than plasterboards. They can be rendered / plastered directly onto, but again recommended to use mesh.
4. Use laths. For ceilings you can now replace old laths with new ones (from Traditional Technologies). These are pre-constructed panels that are nailed into place and then a lime plaster applied. These do not need scrim or mesh and provide a much more authentic finish than plasterboards in older buildings.
So there are a few options to think about. For more info please contact the Eco Home Centre.