Scratch Coats in Plastering

What is the purpose of scratch coats in plastering?

• To add color to the plaster.

• To make the plaster more waterproof.

• To provide a rough surface for the next coat to adhere to.

• To create a smooth finish on the surface.

Which materials are commonly used in scratch coats?

• gravel, cement, water

• brick, cement, water

• wood, cement, water

• sand, cement, water

What are the different application techniques for scratch coats?

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What are some common mistakes to avoid when applying scratch coats?

• Applying the scratch coat too thinly, not properly mixing the scratch coat material, not allowing enough drying time between coats, and not properly preparing the surface.

• Applying the scratch coat too thickly, not properly mixing the scratch coat material, not allowing enough drying time between coats, and not properly preparing the surface.

• Not properly preparing the surface, applying too thick or too thin of a coat, not allowing enough drying time between coats, and not properly mixing the scratch coat material.

• Not properly preparing the surface, applying the scratch coat too thickly, not allowing enough drying time between coats, and not properly mixing the scratch coat material.

True or False: Scratch coats are applied to provide a smooth and even surface for the final coat of plaster.

• False

• True

• Scratch coats are not necessary for the final coat of plaster

• Scratch coats are only used for exterior surfaces

What is the recommended thickness for a scratch coat?

• 1/4 to 3/8 inch

• 1/2 to 3/4 inch

• 1 inch

• 3/8 to 1/2 inch

What is the purpose of keying the scratch coat?

• To prevent moisture from penetrating the wall.

• To provide a rough surface for the next layer of plaster or stucco to adhere to.

• To create a smooth surface for the next layer of plaster or stucco to adhere to.

• To add color and texture to the final finish.

What is the drying time for a scratch coat before applying the next coat?

• 24 hours

• 48 hours

• 12 hours

• 1 hour

What are some alternative names for scratch coats in plastering?

• top coat

• render coat, brown coat, leveling coat

• finish coat

• base coat

What are the advantages of using a scratch coat in plastering?

• A scratch coat provides a rough surface for the next coat to adhere to, improves bond strength, and helps prevent cracking.

• A scratch coat increases the drying time of the plaster.

• A scratch coat makes the surface smoother and more even.

• A scratch coat is not necessary in plastering.