Thistle HardWall backing plaster is first choice for plasterers working with medium to high suction backgrounds.

You can apply it by hand or by spray machine for extra speed and convenience. Thistle HardWall is ideal for most medium to high suction backgrounds, including masonry such as bricks and aircrete block

Thistle HardWall is a gypsum-based undercoat plaster designed for use on a variety of masonry substrates, providing a strong, robust base for finish plasters. It is typically used for medium to high suction backgrounds like brick or blockwork. Here’s a detailed overview of Thistle HardWall, its applications, and some key tips for proper use.

Key Features of Thistle HardWall

• High Coverage: Thistle HardWall offers good coverage, making it an economical choice for large areas. It is typically applied at a thickness of around 11 mm to 25 mm.
• Suitable for Masonry Substrates: This plaster is suitable for most masonry backgrounds, such as bricks and medium-density blocks, making it a versatile option for various projects.
• High Impact Resistance: The plaster provides strong, durable undercoat that can withstand significant impact, making it ideal for heavy-use areas.
• Rapid Drying: It dries more quickly than traditional undercoat plasters, allowing for faster finishing.

Application Process

When applying Thistle HardWall, it is essential to prepare the background properly to ensure the best adhesion and a smooth finish:

1. Prepare the Surface: Before applying Thistle HardWall, ensure that the background is clean, dry, and free from any dust, loose material, or grease. If the background is very dry or high suction, use a suitable primer like Thistle GypPrime to control suction and improve bonding​.
2. Mixing the Plaster: Add the plaster to clean, fresh water (never the other way around) and mix thoroughly until smooth and free of lumps. Follow the manufacturer’s recommendations for water-to-plaster ratio to achieve the right consistency.
3. Applying the Plaster:
   • Apply the first coat of Thistle HardWall to a uniform thickness of around 11 mm.
   • Use a hawk and trowel to ensure even application and a smooth finish.
   • If needed, a second coat can be applied to achieve the desired thickness (up to 25 mm).
4. Trowelling and Finishing:
   • Once the plaster begins to firm up, use a trowel to smooth and level the surface.
   • Depending on site conditions, the plaster can be floated for a finer finish or left rough for a key to receive a finish coat, such as Thistle MultiFinish​​.
5. Drying Time: Drying time for Thistle HardWall depends on ambient conditions, but it typically dries within a few hours. However, the final drying will take longer if the background has higher suction or in cooler environments.

Practical Tips

• Priming High-Suction Backgrounds: For high-suction backgrounds such as lightweight blocks, apply a suction control primer (like Thistle GypPrime) to reduce the rate of moisture absorption, ensuring proper adhesion of the plaster​.
• Avoid Over-Mixing: Over-mixing can lead to air bubbles and weaken the plaster. Aim for a smooth, lump-free consistency without introducing too much air.
• Consider Environmental Factors: Be aware that colder environments may extend drying times, and higher humidity may slow the plaster's setting. Always ensure the work area is adequately ventilated to allow the plaster to dry correctly​.

Conclusion

Thistle HardWall is an excellent choice for undercoat plastering on masonry surfaces. It offers versatility, strength, and durability, making it ideal for both domestic and commercial projects. When applied correctly and paired with appropriate finish plasters like Thistle MultiFinish, Thistle HardWall provides a strong, smooth surface ready for painting or decorating.

For more detailed guidance and additional products, visit the British Gypsum website or consult their comprehensive installation guides​​.

Thistle BondingCoat backing plaster is first choice for plasterers working with smooth or low suction backgrounds.

Its easy to spread and finish thanks to its fine mix and good workability, making it the ideal undercoat on new walls, or for making good old walls before skimming with British Gypsum finishing plaster.

Thistle BondingCoat backing plaster is first choice for plasterers working with smooth or low suction backgrounds.

It's easy to spread and finish thanks to its fine mix and good workability, making it the ideal undercoat on new walls, or for making good old walls before skimming with British Gypsum finishing plasters.

Key facts

• Undercoat plaster for low suction surfaces
• Ideal for new walls, or for making good old walls
• Good workability due to a fine mix
• Ideal for applying directly to plasterboard where dubbing out is required
• Provides an excellent base coat for Thistle finishing plasters
• Pre-treatment is required for painted surfaces

Thistle Bonding 60 lets you patch and repair walls quickly, with no cracking or shrinkage.

The plaster has a 45 minute working time, a 60 minute set, and is ready to skim in just 75 minutes. This makes it ideal when you need to carry out everyday repairs quickly and easily, or when making walls good

Thistle Bonding 60 provides a consistent 60 minute set time. The shorter set time allows patching and repair to be completed in half the time compared to standard Thistle BondingCoat Undercoat Plaster. Coverage based on 11mm thickness.

How does it differ from existing Thistle Bonding Coat?

Aside from the reduced working time (45min) and setting time (60min), Bonding 60 has a different smell and feel to it compared to other Thistle Undercoat plasters. The additional polymers and additives needed has given the plaster a unique texture to work with, often compared to older formulation products in how it feels to work with.

The reduced performance timescales does mean some changes to established site practice – for example Thistle Bonding 60 will set on the edges of tools if left too long before cleaning down. Also, we would strongly recommend using clean water and a clean bucket for mixing up in if you want to avoid inconsistent performance.

What about backgrounds not listed here?

Try a small test area before the larger job.

At the extreme High Suction end of the range, suction control is needed, e.g. with Thistle Bond-it or PVA. Otherwise, crazing or shrinkage might be seen after application of the first coat. If this happens, stop and control the suction before carrying on.

When suction is high but not extreme, suction control may still be advisable sometimes, but is not usually necessary. For example a small high suction patch in an otherwise low suction wall, or a large area of high suction that must be finished in one operation. When suction is low or moderate, or if a smaller high suction area needs finishing, then pre-treatment is not needed.

What are the product benefits of Thistle Bonding 60?

• Thistle Bonding 60 cuts out the dead-time in your small patching jobs and working day
• Excellent workability on medium and low suction backgrounds
• Easy to mix and easy to use, with enhanced workability
• Saves time during the day to get home quicker
• Suitable for use on a wide range of backgrounds in various conditions

What backgrounds are in scope for Thistle Bonding 60?

We would recommend the use of Thistle Bonding 60 on medium to lower suction backgrounds, in renovation and refurbishment applications.

All backgrounds need to be clean, sound and free from dust.

No pre-treatment is needed for;

• Medium-density blocks
• Engineering bricks
• Metal lathing

We would recommend pre-treatment with;

• Dense blocks
• Plasterboard
• Cast-in-situ & pre-cast concrete
• Painted/tiled surfaces
• Ceilings

What is the setting time?

Thistle Bonding 60 does what it says on the sack; set in 60 minutes. We recommend planning for a 45 minute working time, and waiting until 75 minutes before skim. Please note that like other Thistle Plasters you will see set-time performance changes based on the suction of the background and the method of control you apply.