Question 1

How much Thistle plaster do I need per m²?

Accepted Answer

Coverage varies by product and thickness, but as a rule of thumb Thistle finishing plasters need around 1.0–1.2 kg per m² per mm of thickness. For example, a 2 mm skim of Multi‑Finish will consume roughly 2–2.4 kg/m², while a 10 mm undercoat will use about 10–12 kg/m².

Always check the product datasheet for exact yield and allow an extra 5–10% for wastage, and for larger jobs use supplier packaging guidance to order the correct number of bags.

Question 2

Can I use Thistle Multi‑Finish over plasterboard?

Accepted Answer

Yes, Thistle Multi‑Finish is specifically designed to be applied over plasterboard, providing a smooth, durable surface ideal for painting or wallpapering. It creates a flawless finish when applied in a thin coats and is formulated to adhere well to plasterboard and other substrates like skim-coated walls or existing plaster.

For best results, ensure the surface is clean, dry, and free from dust or loose materials, and prime the plasterboard with a suitable stabilising through‑coat if recommended. This versatility makes Thistle Multi‑Finish a popular choice for achieving a high-quality finish in both new build and refurbishment projects.

Question 3

When should I use bonding coat?

Accepted Answer

Use bonding coat when working with low-suction surfaces such as concrete, brickwork, or old masonry, to significantly boost adhesion before applying undercoat or finishing plaster. It is essential in scenarios where the substrate may not naturally provide a strong key for subsequent layers, helping to prevent peeling, cracking, or delamination over time.

Applying a bonding coat creates a stable base that ensures the strength and durability of your plastering system, especially in environments prone to movement or moisture ingress. Always follow product-specific guidance to achieve the best results and ensure a long-lasting, high-quality finish.

Question 4

What’s the difference between Thistle Hardwall and Thistle Undercoat?

Accepted Answer

Thistle Hardwall is a high-strength, textured plaster designed to provide a robust base layer for brickwork, blockwork, or rough surfaces, offering excellent load-bearing capacity and impact resistance. It’s typically used as the initial layer in a two-coat plastering system where a durable, stabilising layer is required before applying a finish.

Conversely, Thistle Undercoat, also known as bonding or base coat plaster, is formulated to create a strong key on low-adhesion substrates such as concrete, old plaster, or poor-quality backgrounds. It provides a solid foundation for the subsequent coats, ensuring good adhesion and reducing the risk of cracks or detachment over time. While both are key components in plastering, Hardwall focuses on offering structural strength and a rougher finish, whereas Undercoat is more about preparing the background for a smooth, high-quality finish.

Question 5

Can Thistle bonding coat be used externally?

Accepted Answer

Thistle bonding coat is specifically formulated for internal use to create a reliable key on various backgrounds before plastering. It is not designed to withstand outdoor weather conditions, such as moisture, rain, or frost, which can compromise its performance and lead to issues like peeling or crumbling.

For external applications, it’s advisable to use an external-grade bonding or render product that is weather-resistant and specially formulated for outdoor environments. Always follow the manufacturer’s recommendations to ensure durability and long-lasting adhesion when working on external surfaces.

Thistle plaster

Thistle MultiFinish Plaster 25kg

Thistle Hardwall Plaster 25kg

Thistle Bonding Coat Plaster 25kg

Thistle BoardFinish Plaster 25kg

British Gypsum Thistlepro Fastset Finish Plaster 25kg

Thistle One Coat Plaster 7.5kg

Thistle Finishing Plaster 7.5kg

Thistle Undercoat plaster, 7.5kg Bag

Thistle 25Kg Dri-Coat Plaster 06115/8

Thistle One Coat Plaster 12.5kg

British Gypsum Thistle Finishing Plaster - 12.5kg

Thistle 25Kg Universal One Coat Plaster 06062/5