Question

The scratch coat of plaster is so named because it is physically scratched to create grooves to which the brown coat can bond. Which of the following tools or techniques is commonly used for this purpose?

A) Trowel
B) Float
C) Comb scratcher
D) Sponge finish

Choose the correct option that best completes the question about the tool or technique commonly used for scratching the plaster's scratch coat in the field of construction or plastering.

Answer 1

The tool used for scratching the scratch coat of plaster in construction is a comb scratcher, which is essential for creating grooves that allow better adhesion for the brown coat.

Step-by-step explanation:

The tool commonly used to scratch the scratch coat of plaster is a comb scratcher. The comb scratcher is designed specifically to create grooves and textures in the scratch coat, which facilitate a better bond with the brown coat. These grooves provide the mechanical key needed for the subsequent layer of plaster to adhere effectively. This step is crucial in the traditional three-coat plaster system, ensuring the layers bond together properly for lasting durability.

Decoration techniques in related fields, such as ceramics, also involve texturing surfaces. For instance, incising lines or creating textures with seashells on clay are analogous to the plaster scratching process in that both methods create a patterned surface that can help additional materials, such as glazes or other layers, adhere better or simply provide decorative effects.