10 things you should know about plaster

What thickness are plasters applied? Undercoat plasters are generally applied 11mm thick (for walls), or 8mm (for ceilings) and finish coat plasters at 2mm thick. Thistle Universal One Coat plaster is applied at 13mm thickness (for walls), or 10mm (for ceilings). Thistle Magnetic Plaster is applied at a minimum of 3mm. What plaster to apply to sand & cement undercoats? The best finish to apply depends on suction level of the background material. Thistle Multi-Finish or Thistle Durafinish would both be suitable. What plaster to use after DPC installed? Thistle Dri-Coat is cement based plaster for re-plastering after a damp proof course. Please refer to the plaster section of the White Book for further information if required. How to plaster an existing painted wall? If the paint is in very good condition in terms of quality, strength and adhesion etc, it may be possible to wire brush the surface using a suitable detergent and apply ThistleBond-it prior to the application of Thistle Multi-Finish. We suggest carrying out this procedure on a trial area to ascertain the suitability. Where would you use Thistle GypPrime? Thistle GypPrime is a suction control primer used to reduce suction on very dry backgrounds. It is normally diluted (up to 5 parts water to 1 part Thistle GypPrime) or undiluted if severe suction control is required. Plaster is applied after Thistle GyPrime has soaked into the background. How can plaster assist in reducing air leakage of a building? Using Thistle plasters to plug gaps and cracks is a quick and easy way of maintaining airtightness. Gyproc SoundCoat Plus is used as a parge coat when using a dot and dab method with plasterboard. Does plastering help increase thermal mass? Thistle plaster is ideal for use where thermal mass is an integral part of the design of a building. Plaster provides the desired decorative finish whilst also enabling efficient heat transfer between the air and fabric of the building. Can I plaster a damp wall? Not if the wall is subject to rising or penetrating damp. Yes, if there is just residual dampness after successful DPC treatment. The wall needs to treated to eradicate any damp issues such as a damp-proof course. Thistle Dri-Coat could be used following a successful DPC installation. Please refer to the plaster section of the White Book for further information if required. How should salt contamination on a background be dealt with? Any salts brought to the surface of the background during drying should be carefully removed. The background must be clean, sound and free from dust. Heavy salt contamination can cause persistent damp problems, so it is important to establish whether the salts are purely from the drying process or whether a more serious damp problem exists. See the White Book for more information. How much plaster is made in a typical week? Barrow-upon-Soar, the home of Thistle Plasters, produce around 440,000 bags of plaster a week – that’s enough to plaster 29,000 homes.