9 Masonry Flashcards
1
Q
What materials are commonly used in modern masonry?
A
Stone, brick, tile, concrete, and other minerals
These materials become strong and durable when used in combination.
2
Q
What is the basic component of all modern masonry mixtures?
A
Portland cement
It reacts chemically with water, hardening the mix and bonding materials together.
3
Q
What is masonry cement also known as?
A
Mortar cement
It is a mix of portland cement and lime.
4
Q
What is the purpose of aggregates in a concrete mix?
A
To add material
Fine aggregate is sand; coarse aggregate is gravel.
5
Q
What is the primary use of mortar?
A
To lay brick, concrete block, stone, and similar materials
Mortar is a mixture of masonry cement and sand or portland cement, lime, and sand.
6
Q
What is grout used for?
A
To fill cracks and joints
Grout is a mix of portland cement and sand or masonry cement and sand.
7
Q
What is the role of reinforcement in masonry?
A
To increase resistance to tensile, shear, and other loads
In concrete, it usually refers to steel rebar.
8
Q
What are admixtures in masonry?
A
Mixtures added to vary the character of masonry
They can add color, increase plasticity, resist chemical action, etc.
9
Q
True or False: Trowels are essential masonry tools.
A
True
They can cut brick, scoop and throw mortar, and shape mortar joints.
10
Q
What are the two types of trowels commonly used in masonry?
A
Bricklayer’s trowels and pointing trowels
Bricklayer’s trowels are 10 to 11 inches long; pointing trowels have blades about 5 inches long.
11
Q
What is the function of jointers in masonry?
A
To compress and shape mortar joints
They help improve the weatherability of the joints.
12
Q
Fill in the blank: The tool used to repoint joints after old mortar has been cut back is called a _______.
A
Tuck-pointing trowel
13
Q
What is the purpose of a brick set?
A
To cut bricks precisely or dislodge deteriorated bricks
It has a cutting edge beveled on one side.
14
Q
What should you do if cement bags appear moisture hardened?
A
Drop the sack 2 to 3 feet above a clean, dry floor
If the shock doesn’t loosen the sack, it should be discarded.
15
Q
What is the highest compressive strength mortar type?
A
Type M
It has a minimum compressive strength of 2,500 psi.
16
Q
What is the compressive strength of Type S mortar?
A
1,800 psi
It has the best tensile strength of any mortar listed.
17
Q
What is the typical weight of a bag of Portland cement?
A
94 lbs
This is the standard weight for a bag of Portland cement.
18
Q
What is the recommended temperature range for exterior masonry work?
A
40°F to 80°F
This range is ideal for setting mortar joints or new concrete.
19
Q
What should you do to protect masonry materials from rain?
A
Elevate sacks on a pallet and cover with sheet plastic
Water causes cement to set, making hardened sacks unusable.
20
Q
What is the function of a mason’s level?
A
To level courses and assess plumb
Better-quality levels have an all-metal casing and replaceable vials.
21
Q
What is a common repair task related to brick?
A
Repointing mortar joints
Other tasks include repairing chimney tops and cleaning bricks.
22
Q
What are the classifications of mortar types based on strength and weatherability?
A
Types M, S, N, O, K
Each type has specific compressive strength and recommended uses.
23
Q
What is the compressive strength of Type M mortar?
A
At least 2,500 psi
Recommended for load-bearing walls and below-grade masonry.
24
Q
What is the compressive strength of Type S mortar?
A
1,800 psi
Best tensile strength, resists wind and soil movement.
25
What is the compressive strength of Type N mortar?
800 psi
## Footnote
Suitable for all above-grade uses, including heavy weathering.
26
What is the compressive strength of Type O mortar?
325 psi
## Footnote
Limited to nonload-bearing interior uses.
27
What is the compressive strength of Type K mortar?
100 psi
## Footnote
Not recommended due to extremely low strength.
28
What is the most versatile mortar type?
Type N
## Footnote
Simplified proportions: 1 part portland cement, 1 part lime, 6 parts sand.
29
What was the common composition of mortar before the 19th century?
Lime and sand
## Footnote
Animal hair was often added to reduce cracking.
30
What is the recommended mortar type for repointing brickwork over 100 years old?
Type O
## Footnote
Proportions: roughly 1 part portland cement, 2 parts lime, 4 parts fine sand.
31
What are the two methods to cut brick?
Using a mason's hammer or a brick-cutting tool
## Footnote
Mason's hammer requires scoring; brick-cutting tool is safer.
32
What is the standard size of brick?
Nominally 8 in. by 4 in. by 2⅔ in.
## Footnote
Actual size is 7⅝ in. by 3⅝ in. by 2¼ in.
33
What are the weathering grades of building brick?
SW, MW, NW
## Footnote
SW for severe weathering, MW for moderate, NW for nonweathering.
34
What does the term bond refer to in masonry?
Adhesion of brick to mortar and joining of individual units
## Footnote
Includes mortar bond, structural bond, and pattern bond.
35
How many bricks are needed per square foot of wall when laying brick?
Approximately 7 bricks
## Footnote
This accounts for waste.
36
What should be done to bricks before using them?
Wet the bricks
## Footnote
Prevents moisture absorption from the mortar.
37
What is the recommended technique for mixing mortar?
Dry mix ingredients first, then add water gradually
## Footnote
Ensure no dry spots and a moist yet stiff texture.
38
What is the proper way to hold a trowel?
Thumb on top of the handle
## Footnote
This provides control and keeps the thumb out of the mortar.
39
What is the purpose of striking mortar joints?
To compress and shape the mortar
## Footnote
Improves weatherability and joint integrity.
40
What are the best joint shapes for shedding water?
Concave, V-shaped, weathered
## Footnote
Concave is the most common and effective.
41
What tool is used for repointing mortar joints?
Tuck-pointing chisel
## Footnote
Narrow blade fits easily into joints.
42
What is the first step in laying brick?
Snap a chalkline to establish a baseline
## Footnote
Ensures alignment for the first course.
43
How thick should bed and head joints be before pressing bricks into place?
1/2 in. to 5/8 in.
## Footnote
Goal is to compress the joint to about 3/8 in. thick.
44
What is a closure brick?
The last brick in a course
## Footnote
Requires liberal buttering of both ends before placing.
45
What is the purpose of repointing mortar joints?
To repair eroded mortar and maintain the integrity of masonry structures.
46
What is the first step in the repointing process?
Use a tuck-pointing chisel to cut back eroded mortar.
47
What types of mortar joints can be created during repointing?
* Flush
* Raked and tooled
* 'V'
* Extruded
* Struck
* Concave
* Weathered
48
What tool is recommended for raking old mortar?
Tuck-pointing (plugging) chisels or an 18-volt cordless grinder.
49
What should be done if bricks are loose during repointing?
Remove them until reaching bricks that are solidly attached.
50
What is the recommended depth for cutting joints during raking?
1 inch deep.
51
Fill in the blank: Before applying fresh mortar, dampen the newly cleaned-out joints with a _______.
spray bottle or brush
52
What is the composition of type O mortar?
* 1 part portland cement
* 2 parts hydrated lime
* 8 parts fine sand
53
What is the purpose of using a grout bag in repointing?
To fill joints with new mortar in larger areas.
54
What should be done after using a grout bag?
Tuck-point the mortar joints.
55
When should safety goggles and a respirator be worn during mortar work?
When cutting mortar and performing cleaning tasks.
56
What is the gentlest method for cleaning brick surfaces?
Using a garden hose to soak the surface and scrubbing with a nylon scrub brush.
57
What can happen if a pressure washer is set too high while cleaning mortar joints?
It may strip the mortar joints.
58
True or False: Muriatic acid is safe to use for cleaning masonry surfaces.
False
59
What is the main function of water-repellent coatings on masonry walls?
To keep rain from penetrating while allowing water vapor to escape.
60
What are the two categories of exterior sealants mentioned?
* Water-repellent coatings
* Waterproof coatings
61
What is a crucial maintenance step for masonry chimneys?
Annual inspections and maintenance.
62
What should be done before adding a door or window to a brick wall?
Hire a structural engineer to assess feasibility.
63
What are the risks associated with brick veneer walls built in the 1960s or later?
They can be fragile due to corroding metal ties.
64
Fill in the blank: Soft, lime-rich mortars show _______ healing, an ability to self-repair hairline cracks.
autogenous
65
What is the recommended approach to cleaning brick surfaces in urban areas?
Use nonionic detergents with medium pressure.
66
What should be tested before committing to a cleaning method?
The method should be tested in an inconspicuous area.
67
What is the consequence of trapping water inside masonry walls?
It can lead to efflorescence, a powdery white substance.
68
What should you do before adding a door or window to a brick wall?
Hire a structural engineer to see if that's feasible.
69
What type of brick wall is likely to be fragile if built after the 1960s?
Brick veneer.
70
What is a common issue with metal ties in brick veneer walls?
They tend to corrode, especially in humid or coastal areas.
71
What structural support is needed when opening brick walls built before the 1960s?
Steel lintels.
72
What is the process to close off an opening in a brick wall?
Remove the window or door, tooth out the opening, and fill with whole bricks.
73
What should be done to match the color of the new bricks when closing a brick wall?
Match the color of existing bricks and mortar as closely as possible.
74
How often should chimneys and their flues be inspected?
At least once a year.
75
What is the ideal time to clean a chimney?
Before the heating season.
76
What can professionals use to inspect the chimney flue linings?
A video camera.
77
What is a major risk when cleaning a chimney from the roof?
It is inherently dangerous and can damage roof shingles.
78
What should you wear when cleaning a chimney yourself?
A respirator, goggles, gloves, and disposable coveralls.
79
What types of brushes do professionals typically use for cleaning chimneys?
* Polypropylene brushes for sooty flues
* Stiff steel-wire brushes for heavy use and creosote buildup.
80
What is the root cause of a chimney fire?
Imperfectly burned material in wood smoke condensing and sticking to the chimney.
81
What is creosote?
A sticky brown or black substance that may harden to the consistency of glass.
82
What can happen if there are cracks in mortar or flue tiles during a chimney fire?
Superheated gases can breach the chimney and set fire to wood framing.
83
What materials should not be burned in a chimney to prevent fires?
* Green (unseasoned) wood
* Wet wood
* Christmas trees
* Wrapping paper
* Glossy-coated papers.
84
What should you do if you see signs of a chimney fire when inspecting a house?
Have its chimney professionally inspected.
85
What is the function of a masonry crown on a chimney?
To direct water away from flue tiles.
86
What happens if a chimney crown cracks?
Water can drain between flue tiles and brick, leading to damage.
87
What should be done to replace a deteriorating chimney crown?
Sweep the chimney clean, repoint mortar joints, and rebuild if necessary.
88
What is the recommended concrete mix for constructing a new chimney crown?
1 part portland cement, 2 parts sand, and 2 parts 3/8-in. gravel.
89
What should be used to prevent mortar and concrete from bonding to flue tiles?
Polyethylene bond-breaker tape or closed-cell foam strips.
90
What are the two types of chimney crowns?
* In-place concrete crown
* Sloping mortar crown.
91
What should you do before pouring concrete for a chimney crown?
Wet the bricks.
92
What is a common method for relining a chimney?
Installing a poured masonry liner or a stainless-steel flue.
93
What is a poured masonry liner?
A heavy-gauge tubular rubber balloon inflated inside the chimney and filled with a cementitious slurry.
94
What is a stainless-steel flue liner known for?
Being a quick and effective solution for chimney issues.
95
What is the minimum clearance required around a stainless-steel flue pipe?
At minimum 1 inch.
96
What should be done to ensure stability when installing a flue pipe?
Join pipe sections with four stainless-steel sheet-metal screws per joint.
97
What type of vacuum is recommended for cleaning soot from chimneys?
A commercial-grade canister vacuum with superfine filters.
98
What should be done to the flue pipe before installation?
Assemble it on the ground and ensure it is insulated as necessary.
99
What should be installed before the flue liner?
The stove or fireplace insert
## Footnote
Installing the stove first allows for easier assembly of the flue liner.
100
How should pipe sections be joined during flue pipe assembly?
With four stainless-steel sheet-metal screws per joint
## Footnote
This ensures that the sections stay together as they are lowered down the chimney.
101
What is the purpose of insulating flue pipes?
To keep temperatures constant inside and prevent condensation
## Footnote
Preventing condensation also helps to avoid the accretion of corrosive creosote.
102
What temperature can flue pipes intermittently reach?
2,000°F
## Footnote
This high temperature necessitates proper insulation to prevent condensation.
103
What is the purpose of a metal top plate in flue installation?
To center the pipe within the chimney and seal it at the top
## Footnote
It is caulked with a high-temperature silicone sealant.
104
What safety precautions should be taken when working on roofs?
Wear safety harnesses and minimize ladder trips
## Footnote
Use buckets to lower debris and avoid standing on slippery tarps.
105
What is the first step in rebuilding a firebox?
Measure the firebox dimensions
## Footnote
This includes height, width, depth, and angles of the walls.
106
What type of bricks should be used to rebuild the back wall of a firebox?
New firebricks
## Footnote
These bricks can withstand the most intense heat.
107
What should be done before tearing out old firebricks?
Take digital photos of the firebox
## Footnote
Photos help keep track of dimensions and angles for rebuilding.
108
What is the recommended thickness for firebrick mortar joints?
1/16 in. to 1/8 in. thick
## Footnote
This tight joint is necessary for effective insulation.
109
What type of mortar is best for setting firebricks?
Hydraulic-setting refractory mortar
## Footnote
It cures rather than dries and is acid resistant.
110
True or False: Air-set refractory mortar is water-soluble and sets more quickly than hydraulic-setting mortar.
True
## Footnote
Air-set mortar allows for easier clean-up but requires careful handling.
111
What should be done to reduce air turbulence inside the smoke chamber?
Give the corbeled bricks a smooth parge coat
## Footnote
This involves brushing, vacuuming, and wetting the bricks before applying heat-resistant mortar.
112
What is the minimum height requirement for a chimney?
3 ft. above the part of the roof it passes through and 2 ft. above any other part of the roof within 10 ft.
## Footnote
This height helps ensure proper updraft.
113
What is the purpose of a fireplace insert?
To provide an efficient heating solution compared to traditional fireplaces
## Footnote
Glass-doored stoves allow for flame visibility while improving energy efficiency.
114
Fill in the blank: Firebricks are made of _______ and can withstand temperatures up to 2,000°F.
[fire clay]
## Footnote
Firebricks are larger and softer than conventional bricks, making them suitable for high-heat applications.
115
What is the recommended method for cleaning and repointing mortar joints in a firebox?
Use a margin trowel for packing fresh mortar into joints
## Footnote
A tuck-pointing trowel can help in scraping mortar into the joints.
116
What is a smoke shelf in a fireplace?
The area created between the firebox and the rubble-brick walls where smoke collects
## Footnote
It can be flat or slightly cupped to aid in smoke flow.
117
How should firebricks be seated in mortar?
Gently use a mason’s hammer
## Footnote
Ensure bricks are properly aligned and level during installation.
118
What kind of adhesive is suitable for dressing up a concrete wall?
SGM Marble Set or epoxies
## Footnote
Ensure the adhesive is suitable for exterior use in freezing conditions.
119
What should you check regarding adhesive suitability?
Manufacturer’s instructions for exterior use in your area
## Footnote
Especially important if you have freezing winters
120
What type of bricks should be used for exterior applications?
Exterior-grade bricks
121
How does the design of the facade depend on the building?
On the building’s style and your sense of fun
122
What is an example of a facade style that complements Craftsman houses?
Clinker brick, tile, and stone facade
123
What is the importance of packing joints with mortar?
To shed water, especially in freezing temperatures
124
What freedom does not relying on mortar joints provide?
Freedom in design
125
What can today’s masonry adhesives adhere to?
Heavy materials such as brick, stone, and tile directly to concrete
126
What should you do to the backs of masonry elements?
Butter them with adhesive
127
What is the purpose of using short sticks when placing bricks?
To prevent slippage before the adhesive sets
128
What should you do with the mortar to ensure it adheres properly?
Compress and shape the mortar
129
Fill in the blank: Mortar joints can be as expressive as you like when they are _______.
Freed from needing to support much of anything
