Basic Fixing of Fibrous Plasterwork

The method used to fix fibrous plasterwork in place depends on the background, weight of the cast, size shape and the positioning of it in the building. You should always check the architect drawings before fixing fibrous plasterwork into place to make sure the mouldings are right. When fixing fibrous plasterwork to the background, you should always make sure the background is sturdy to stop any movement, strong enough to be able to hold the weight and dry. Tapping the background lightly with a hammer will show if there is any loose plaster. Loose plaster has to be removed before fixing the plasterwork. If the background has a hollow sounding ring to it, then the plaster has not bonded and the fixings can pull it off the wall. Centre lines and datum points must be used when setting out. Centre are the best to use for mouldings that are positioned on walls or ceilings. Sometimes grid lines can be set out for fixing. There are 6 different types of internal mouldings; Cornice - a moulding that is fixed between the wall and the ceiling. Picture rail - a moulding that is fixed below the cornice Panel - an area on the wall that is either a square or a rectangle Dado rail - is also known as a chair rail as it is fixed the wall at chair height Skirting - a moulding at the bottom of the wall Architrave - a moulding that goes around doors and windows. The type of fixing used varies depending on the conditions. Screws are used for regular wood backgrounds like timber joints. Brass, sheradised and zinc-plated screws should be used, although brass screws are easy to break as they are soft. The size of the screw used will depend on a few things such as the size and weight of the cast and depth the screw needs to go to meet the fixing point. Plain galvanised and non rusting nails can be used. They have an increased strength to hold materials because of the ringed shank they have. The size of the nail needed varies depending on the required fixing. There are different types of bolts and screws that can be used for fixing but they vary depending on the type of fixing. For solid backgrounds, wall bolts and drill anchors can be used. For hollow backgrounds, toggle bolts can be used. To help with strengthening the fixing when using nails and screws, sometimes you might need to drill a hole and plug it. These plugs are known by a few names; rawlplugs, plasplugs and fischer plugs. They are made from plastic and come in various colours depending on the size,