8.2a KNOW CONSTRUCTION MATERIALS & THEIR PROPERTIES

Question 1

A01 - 3 FUNCTIONS OF FILMS & COATINGS ON WINDOWS:

Answer 1

• REFLECT SOLAR HEAT BACK OUT
• REFLECT RADIANT HEAT BACK IN
• REDUCE TRANSMISSION OF UV RAYS

Question 2

A02 - 5 PROS / CONS of SEALED WINDOWS:

Answer 2

+ 2 SURFACES TO CLEAN RATHER THAN 4
+ NO CONDENSATION BTWN GLASS
+ ABILITY TO INCORPORATE •COATINGS•FILMS•GASES
- METAL SPACER = THERM. BRIDGE (can cause condensation along cold perimeter of glass)
- DEFLECTION DUE TO CHANGE IN TEMP. & WIND PRESSURE = COMPRESSION AND TENSION CYCLE ON SEALANT (can cause failure)
-

Question 3

A03 - PROS / CONS of UNSEALED WINDOWS:

Answer 3

+ NO NEED TO BE REPLACED DUE TO CONDENSATION

• CANNOT ACCOMMODATE MANY: •FILMS•COATINGS•GASES
• SEPARATE SASH OPTION TYP. ONLY AVAIL. IN SLIDING

Question 4

A04 - WHAT WINDOW FRAME TYPE IS BEST FOR HIGH RISE & COMMERCIAL & WHY?

Answer 4

ALUMINUM - b/c they can be designed to meet specific structural requirements

Question 5

A05 - PROS / CONS OF PVC WINDOWS:

Answer 5

+ LOW MAINTENANCE
+ STABLE IN SALINE / POLLUTED AIR
- STEEL IN SASH / FRAME FOR STABILITY = INCREASED THERM. CONDUCTIVITY
- RISK OF COHESIVE FAILURE @ JOINT
- LIMITED LIGHT TONES b/c of •FADING •EXPANSION DUE TO DIRECT SUN

Question 6

A06 - What are the nominal brick sizes for:
1 - modular
2 - norman
3 - utility

Answer 6

**nominal brick sizing includes mortar joints
1 - modular 100 x 68 x 205
2 - norman 100 x 68 x 305
3 - utility 100 x 100 x 305

Question 7

A07 - What are these 3 types of face brick:
1 - FBX
2 - FBS
3 - FBA

Answer 7

1 - FBX = perfect/high degree of uniformity
2 - FBS = wider range of acceptable colour
3 - FBA = desired non-uniformity

Question 8

A08 - What is efflorescence?

Answer 8

Powdery deposit on face of brick, due to leaching and crystallization of soluble salts within material

Best defence: reduce moisture absorption

Question 9

A09 List and describe the 6 main varieties of brick. (example: soft mud)

Answer 9

1 - SOFT MUD
• form brick w wet clay (20-30% moist)
2 - SANDSTRUCK (matt texture)
• form w form lined w sand to prevent sticking
3 - WATERSTRUCK (smooth dense surface)
•form lubricated w water
4 - STIFF MUD
• extruding stiff but plastic clay (12-15% moist)
5 - DRY PRESS (sharp edge smooth surface)
• form relatively dry clay (5-7% moist)

Question 10

A10 What are brick grades a measure of?

Answer 10

Brick grades measure durability when exposed to weathering. According to:
• compressive strength • max H20 absorb • max saturation coefficient

Question 11

A11 What do the 3 brick grades below indicate:
1 - SW
2 - MW
3 - NW

Answer 11

These grades indicate suitable weather regions
1 - SW = Severe Weather
(min. comp. str. 2500psi)

2 - MW = Moderate Weather
(min. comp. str. 2200psi)

3 - NW = Negligible Weather
(min. comp. str. 1250psi)

Question 12

A12 In order of highest strength to lowest, list the 3 types of concrete used in concrete masonry units.

Answer 12

• Normal
• Medium
• Lightweight

Question 13

A13 What do CMU grades indicate?

Answer 13

Suitability for load bearing:
N = Loadbearing below and above grade
S = Loadbearing above grade only

Question 14

A14 How can you identify if CMUs have been manufactured to have a certain moist. content to prevent shrinking & cracking?

Answer 14

Type 1 = manufacture to have certain moist content

Type 2 = not manuf. to have cert. moist. content

Question 15

A15 What is the nominal size of a typical CMU block?

Answer 15

8 x 8 x 16”

205 x 205 x 405mm

Question 16

A16 Steel is defined as various iron based alloys w carbon content ____ than cast iron & ____ than wrought iron.

Answer 16

less carbon content than cast iron

more carbon content than wrought iron

Question 17

A17 Steel is incombustible but ductile and loses strength at temperatures over:

Answer 17

520 deg C

Question 18

A18 List 3 ways steel can be protected from oxidization

Answer 18

• painted
• galvanized
• treated

Question 19

A19 What are the 2 main types of steel? Describe their properties.

Answer 19

1 - CARBON
- unalloyed
- residual elements controlled
**more carbon = less ductility/weldability
2 - ALLOY
- carbon steel w other elements added to obtain particular physical/chemical properties

Question 20

A20 What are these 4 types of steel composed of and what is their function?

1 - STAINLESS
2 - HIGH STRENGTH LOW ALLOY
3 - WEATHERING STEEL
4 - TUNGSTEN STEEL

Answer 20

1 - STAINLESS (min. 12% chromium)
= highly resist. to corrosion

2 - HIGH STRENGTH LOW ALLOY
• low carbon w <2% alloy
= high strength/ductility + low corrosion

3 - WEATHERING STEEL
• forms an oxide coating when exposed to rain/moisture
= protects from further corrosion

4 - TUNGSTEN STEEL
• contains 10-20% tungsten
= increased hardness + heat retention

Question 21

A21 There are Ferrous metals other than steel, describe just 2 of them:
1 - Cast Iron
2 - Wrought Iron

Answer 21

1 - CAST IRON
• hard • brittle • cast in sand • ornamental
2 - WROUGHT IRON
• soft = readily forged & welded

Question 22

A22 List 3 main NONferrous metals.

Answer 22

*nonferrous = metals containing no iron
1 - Aluminum
2 - Copper
3 - Brass

Question 23

A23 What are the advantages(4) of Aluminum and largely how is it used?

Answer 23

1 - Ductile
2 - Malleable
3 - Light
4 - Natural Corrosion resistance
(can be improved by anodizing)

Wide use as 2nd building elements:
• windows
• door frames
• flashing
• trim

Question 24

A24 What MUST always be separate from aluminum and why?

Answer 24

Other metals and alkaline matter:
• wet concrete
• mortar
• plaster

To prevent GALVANIC ACTION!

Question 25

A25 What are the advantages(4) of Copper and largely how is it used?

Answer 25

1 - Ductile
2 - Malleable
3 - Resistance to corrosion (roofing/flashing)

Wide Use:
•roofing/flashing
• wiring
• piping
• manufacture of alloys (bronze/brass)

Question 26

A26 What is GALVANIC ACTION?

Answer 26

Occurs between 2 dissimilar metals if enough moisture for electric current to flow.
• tends to corrode the more noble metal and plate the least noble:

Corrode Noble
(gold, titanium, stainless, bronze)
Plate Least Noble
(Zinc, Aluminum, Cast Iron, Nickel)

Question 27

A27 With high and low pressure on either side of a wall, which way is the moisture in air likely to move?

Answer 27

1 - It will always migrate towards the lower air pressure.

Question 28

A28 Define:
1 - Air Vapour Barrier
2 - Vapour Retarder
3 - Moisture Barrier

Answer 28

1 - Air Vapour Barrier
• material of low permeance
• prevents moist. from entering /condensing

2 - Vapour Retarder
• vapour resistant material of <1 perm
(can apply to gwb!)
• 3 classes (nearly impervious, <1 perm, 1-10 perms)

3 - Moisture Barrier
• typically used below slab to prevent ingress of ground moisture

Question 29

A29 What are the advantages of ceramic tile? (5)

Answer 29

\+ durable
\+ dense 
\+ water resistant
\+ easy to clean 
\+ colours do not fade

Question 30

A30 What are the advantages of Resilient Flooring?

Answer 30

\+ economical
\+ dense
\+ non-absorbant
\+ durable
\+ easy to maintain

Question 31

A31 List some of the most common types of resilient (can restore their shape) floors:

Answer 31

1 - sheet vinyl
2 - vinyl comp. tile
3 - cork tile
4 - cork tile w vinyl coat
5 - rubber tile
6 - linoleum sheet 
7 - linoleum tile

Question 32

A32 Describe these 5 types of carpet:
1 - tufted
2 - woven
3 - knitted
4 - fusion bonded
5 - flocked carpet
6 - needle punched

Answer 32

1 - tufted
• stitch yarn through fabric @ back
2 - woven
• interweave backing /pile yarns in a loom
3 - knitted
• looping the backing, stitching, and pile yarns w 3 sets of needles
4 - fusion bonded
•heat fuse to vinyl back
5 - flocked carpet
• loops of backing/stitching . pile yarns
6 - needle punched

Question 33

A33 What would the highest quality grade be for SOFTWOOD and HARDWOOD VENEERS?

Answer 33

SOFTWOOD
N - select, smooth surface for natural finishes

HARDWOOD
Premium grade - permits only a few small buts, knots and inconspicuous patches.