British Gypsum Thistle Multi Finish is a high-quality multi-purpose gypsum-based finishing product, made up of a retarded hemihydrate, pre-mixed gypsum plaster.
It is a jointing and plaster compound used as a base coat for other plasters on all plaster and plasterboard backgrounds. The perfect product for skimming and filling plasterboard applications.
Thistle Multi Finish is widely used within the construction industry. This product is quick and easy to apply and has a speedy and reliable setting time. The multi finish gives a smooth finish to internal walls and ceilings that is long lasting and durable. This compound makes for the perfect seamless base to apply decoration and finishings such as plaster, paint, and wallpaper.
The gypsum-based powder is fine and when mixed correctly, dries to a smooth finish that does not require sanding. The plaster comes in 25kg and has a coverage of 10m2 when applied with a 2mm thickness and can be applied to small or larger areas with a drying time of just 1.5 hours.
Where to Use Multi Finish
Multi Finish can be applied to flat surfaces treated with bonding agents. This includes plasterboard, multi-board, flat concrete, brickwork, and masonry walls. It’s also suitable for medium-high suction gypsum or cement-based undercoat plasters.
Multi finish can be used to fill board joins and to patch walls and ceilings. Multi finish is a well-used product when filling tapered edge plasterboards at the joins. The multi finish gives an easy seamless finish ready for completion of the area. When applied correctly the multi finish compound can provide a smooth area that may not require plastering to decorate.
British Gypsum Thistle Multi Finish Key Features:
- Easy to Apply
- Quick drying time of up to 2 hours
- Durable and long-lasting
- Should not be applied to moisture-resistant boards or vapour panels
- Suits most common backgrounds
- Provides airtightness and seals gaps, limiting flanking routes for sound transfer
- The smooth surface is ideal for decorating
- All suction backgrounds including undercoats, plasterboards, re-skimming
- Pre-mixed gypsum final coat plaster
- How To Use British Gypsum Thistle Multi Finish
Protective wear such as googles, and face masks are recommended when mixing and applying multi finish to avoid irritation.
Only use Thistle finishing plasters on the face of the board, which is the side without a paper overlap.
Add the multi finish to clean water and ensure the mixing equipment is also clean. Contamination from previous compound can affects the setting time and durability. Fresh contamination has a larger effect than old, be sure to wash equipment after mixing as opposed to just before.
Thistle plasters can be mixed by hand or by using a mechanical whisk with a slow speed. While mechanical mixing speeds up the process, when smooth there is no need to continue mixing. Over-mixing wastes time and affects the quality of the product.
Applying to different substrates
Firstly, prior to plastering, apply tape so you can fix them to the board’s surface before the first application of plaster. If you’re using Joint Tape, embed it in the first coat over each joint, leaving enough plaster under the tape to ensure good adhesion. Then press the tape firmly into the plaster and immediately cover it with a further application.
Secondly, apply plaster to the whole surface after the joint treatment has partially set but not dried. Some joints will experience more movement, such as around door or window apertures, where board edges aren’t fully supported, or on ceilings below floors that are susceptible to high deflection. In these areas, embed Joint Tape in the finish.
Then, fix Angle Beads to plasterboard angles and corners by embedding them in dabs of finish plaster. Avoid fixing the bead to the board ‘dry’; this could reduce the adhesion as it’s difficult to squeeze plaster between the bead and the plasterboard.
After that, to hold the bead in alignment as the plaster sets, we recommended you use additional mechanical fixings like non-rusting nails, screws, and staples.
Finally, apply the finish plaster with a firm pressure and build it out to the required thickness in two applications, trowelling to a smooth matt finish as it sets.
Things to Consider with British Gypsum
Thistle plasters aren’t suitable for plastering onto frozen backgrounds. The plaster can be applied in cooler temperatures however the plaster cannot be allowed to freeze once it has been applied. Dry, bagged plaster isn’t affected by low temperatures.
On the other hand, once Thistle plasters are fully set and dry, they cannot be exposed to high temperatures above 49°C. When applying in dry conditions or hot conditions, make sure the plaster does not lose water quickly, as it needs some of the mixing water to set and reach full potential.
When exposing the plaster to moisture or condensation repeatedly or for long periods of time can cause the plaster to lose strength and adhesion.
This is a guide only. Ensure you consult an architect or building professional to ensure the product and methods are right for your property.