CCS Masonry & Mortar Repair Techniques 3

Question 1

What tool is specifically designed to remove old mortar from chimney joints without damaging the brick?

Accepted Answer

Oscillating tool with carbide grout blade

Answer

An oscillating multi-tool with a carbide grout removal blade provides controlled cutting action that removes mortar while minimizing risk to adjacent brick faces.

Question 2

Efflorescence on a chimney's brick surface is caused by:

Accepted Answer

Soluble salts carried to the surface by evaporating moisture

Answer

Efflorescence is a white crystalline deposit formed when water dissolves soluble salts within the masonry and deposits them on the surface as it evaporates.

Question 3

When using hydraulic cement to repair a chimney's water entry point, at what stage of workability should it be applied?

Accepted Answer

While still plastic and pliable, just before it begins to set rapidly

Answer

Hydraulic cement must be shaped and pressed into place while still workable because it sets very rapidly (often in 3-5 minutes) and expands slightly as it hardens to seal the leak.

Question 4

A chimney sweep finds that the mortar between the smoke chamber corbeling is crumbling. The BEST repair approach is:

Accepted Answer

Apply parging with a refractory or heat-resistant mortar coating

Answer

Parging the smoke chamber with a refractory mortar provides a smooth, heat-resistant coating that seals the corbeled joints and improves draft efficiency.

Question 5

What is the primary function of lime in mortar mixes used for chimney repointing?

Accepted Answer

It provides plasticity, water retention, and allows slight flex to accommodate movement

Answer

Lime adds workability and plasticity to mortar while allowing minor movement without cracking, which is critical for chimneys subject to thermal cycling.

(CCS) Certified Chimney Sweeper Practice Test

(CCS) Certified Chimney Sweeper Practice Test

CCS Masonry & Mortar Repair Techniques 3