Applying Thistle BondingCoat Plaster: Techniques and Guidelines

A comprehensive guide on the process and techniques to apply Thistle BondingCoat plaster on various types of surfaces, ensuring effective and long-lasting results.

Introduction

Plastering is a crucial skill in construction that ensures smooth and aesthetically pleasing walls and ceilings. One of the key materials used in plastering is Thistle BondingCoat, a versatile and durable undercoat plaster suitable for various backgrounds. This article provides detailed guidance on the application techniques and background preparations needed to achieve professional results.

Background Preparation

Solid Backgrounds

When working with solid backgrounds, it is essential to follow specific steps to ensure the plaster adheres properly:

• Before applying the plaster, use the Thistle Essential Selector Guide to check the background's suitability.
• Ensure the surface is dry, clean, and protected from adverse weather conditions.
• For concrete backgrounds, remove any mould oil or other agents from the surface. Wetting no-fines concrete before plastering is unnecessary.
• Allow normal ballast concrete sufficient time to mature before applying the plaster.

Moisture Resistant Boards

In environments with high humidity, moisture resistant boards are recommended to prevent the plaster from losing strength and adhesion. Here are some key points to consider:

• Skim moisture resistant boards only after the building envelope is weather tight.
• Pre-treat the face of moisture resistant boards with Thistle Bond-it before applying the plaster.

Mixing and Application

Thistle BondingCoat plaster is to be mixed and applied correctly to ensure optimal performance. Here are the steps:

Mixing

• Add approximately 14 litres of clean water per 25kg bag of plaster to the mixing bucket.
• Gradually add the plaster while mixing to avoid excessive mechanical mixing, which can affect the plaster’s consistency.

Application

When applying Thistle BondingCoat plaster, follow these guidelines:

• Apply a layer of 11mm thick plaster (for ceilings) or 8mm (for plasterboards).
• Use a trowel or rule to flatten the surface as required for the job size.
• Continue to flatten and, when firm, scour with a sponge float to raise the fines to the surface.
• Trowel progressively to achieve a smooth matt surface.

Timing and Conditions

The timing and environmental conditions significantly affect plaster application:

• Finishing times are reduced by suction and extended in cold weather conditions.
• Avoid exposing plaster to temperatures above 49°C to prevent it from losing water too quickly, which is essential for setting and reaching full strength.

Conclusion

Thistle BondingCoat plaster is a reliable choice for plastering various backgrounds, provided the correct preparation and application techniques are followed. By adhering to these guidelines, plastering professionals can achieve high-quality, durable finishes suitable for different construction environments.