CCS Masonry & Mortar Repair Techniques 2

Question 1

When repointing a chimney, how deep should old mortar be removed before applying new mortar?

Accepted Answer

At least 3/4 inch (19mm)

Answer

NFPA 211 and masonry standards require removal of at least 3/4 inch of old mortar to ensure adequate bonding depth for new mortar.

Question 2

Which mortar type is most appropriate for repointing historic or older brick chimneys?

Accepted Answer

Type N mortar

Answer

Type N mortar (1:1:6 ratio) is softer and more flexible, compatible with historic brick that can be damaged by the strength of Type S or M mortars.

Question 3

What is the primary cause of spalling brick on a chimney exterior?

Accepted Answer

Water penetration followed by freeze-thaw cycling

Answer

Spalling occurs when water absorbed into the brick expands as it freezes, fracturing the brick face in repeated freeze-thaw cycles.

Question 4

A chimney technician notices mortar joints that are concave (slightly hollowed inward). This joint profile is called:

Accepted Answer

Rodded or tooled joint

Answer

A rodded or tooled joint is formed by pressing a rounded tool into the mortar to create a concave profile that sheds water effectively.

Question 5

When mixing repointing mortar, which ingredient ratio describes Type S mortar?

Accepted Answer

1 part portland cement : 1/2 part lime : 4.5 parts sand

Answer

Type S mortar uses a 1:1/2:4.5 ratio of portland cement:lime:sand, providing high strength and good adhesion for below-grade and exterior applications.

(CCS) Certified Chimney Sweeper Practice Test

(CCS) Certified Chimney Sweeper Practice Test

CCS Masonry & Mortar Repair Techniques 2