Roof Claddings

Question 1

What are three common types of roof tiles installed by subcontractors?

Answer 1

Clay, concrete, and slate

Question 2

Name two properties of slate roof tiles.

Answer 2

Durable and natural.

Question 3

How are roof tiles typically fixed?

Answer 3

Laid overlapping and fixed with nails or clips to battens.

Question 4

What are three types of shingles commonly installed by subcontractors?

Answer 4

Asphalt, wood (cedar), and synthetic (bitumen).

Question 5

Before tile or membrane subcontractors arrive, what should be confirmed regarding the roof framing?

Answer 5

Confirm that the spacing of rafters, purlins, and battens (if required) matches the manufacturer’s specifications.

Question 6

What should be checked regarding the underlayment before tile or membrane installation?

Answer 6

Ensure the specified underlayment is correctly installed according to codes and manufacturer instructions, including proper overlaps and secure fixing.

Question 7

Compared to trapezoidal, what is a limitation of corrugated roofing regarding water runoff?

Answer 7

Requires a higher suited pitch for effective water runoff.

Question 8

Describe the spanning capability and strength of trapezoidal longrun roofing compared to corrugated.

Answer 8

Better. The shape provides better rigidity and allows for wider purlin spacing.

Question 9

What is a key advantage of trapezoidal longrun roofing for lower pitched roofs?

Answer 9

Better water carrying capacity due to flatter pans and defined ribs.

Question 10

Which of the three longrun profiles (corrugated, trapezoidal, trough) has the highest water carrying capacity?

Answer 10

Trough.

Question 11

Which longrun profile generally has the highest installation cost?

Answer 11

Trough.

Question 12

How is corrugated longrun roofing typically fixed?

Answer 12

Typically fixed through the crests of the corrugations.

Question 13

How is trapezoidal longrun roofing typically fixed?

Answer 13

Typically fixed through the flat pans.

Question 14

To ensure purlin placement suits the roofing iron, what documents should be checked?

Answer 14

Manufacturers’ specifications, building plans, and engineer’s structural designs.

Question 15

Name two types of perimeter edge blocking/fixing to consider for longrun roofing.

Answer 15

Barge boards and end wall flashings with appropriate support.

Question 16

Name two types of roof intersection blocking/fixing to consider for longrun roofing.

Answer 16

Ridge capping and hip capping (also valley gutters).

Question 17

What type of fasteners should be used for fixing longrun iron?

Answer 17

Correct type, size, and spacing of corrosion-resistant fasteners with sealed washers.

Question 18

What is the primary purpose of roofing underlayment regarding weather?

Answer 18

Temporary weather protection during construction delays and control runoff from leaks.

Question 19

What is the secondary function of roofing underlayment related to water?

Answer 19

Acts as a crucial backup to prevent water from reaching the roof deck and interior.

Question 20

Why is netting sometimes laid under roofing paper on low-pitched roofs?

Answer 20

To prevent sagging or ponding of the underlay between purlins.

Question 21

Name four types of roof flashing.

Answer 21

Barge, valley, eave, ridge

Question 22

What is the typical longrun roofing overhang past the fascia for a roof pitch between 10 and 35 degrees?

Answer 22

50mm

Question 23

For a roof pitch above 35 degrees, what is the general longrun roofing overhang past the fascia?

Answer 23

40mm.

Question 24

In all roof pitches in VH wind zones, what is the minimum barge flashing coverage over the ridge?

Answer 24

70 mm.

Question 25

What is the deciding factor when choosing which end of the roof to start lapping longrun roofing?

Answer 25

Lap opposite the prevailing wind.

Question 26

Why should longrun roofing be lapped opposite the prevailing wind?

Answer 26

To prevent wind uplift under the overlapping edge.

Question 27

In an extreme wind zone, describe the screw pattern for fixing longrun roofing.

Answer 27

Hit one, miss one, hit one, miss one (consider heavier material as well).

Question 28

Name three tools used for the set out and cutting of a skylight opening.

Answer 28

Measuring tape, chalk line, roofing square (and others like level, nibbler, metal shears).

Question 29

Name three components used in the installation of spouting.

Answer 29

Spouting bracket, stop end, jointer (and others like external angle, internal angle, expansion outlet).

Question 30

What is a key factor that determines the size (width) of spouting and downpipes?

Answer 30

Expected volume of water (other factors include roof pitch, length of run, roof area, amount of fall).

Question 31

What is the minimum recommended fall for spouting?

Answer 31

5mm for every 10m (1:200).

Question 32

What is the basic first step in the sequence of installing spouting?

Answer 32

Measure the length of the run.