Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

APC Technical > Building Pathology > Flashcards

Building Pathology Flashcards

1
Q

Can you name four types of insect that damage timber?

A
  • Furniture Beetle
  • Longhorn
  • Powder post
  • Death watch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the differences between wet and dry rot?

A
  • both fungal decay and can cause structural damage.
  • Dry rot is more serious
  • Wet rot is more common and can spread through other damp materials.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What reasons does pointing fail?

A
  • improper preparation
  • Unsuitable mix
  • Strap pointing can get water sitting and blow with frost damage.
  • Improper mortar
  • Frost damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the advantages and disadvantages of MMC?

A
  • Quicker on site.
  • Benefit from factory conditions and QA
  • Retained building performance.
  • Cost (higher than average).
  • Sustainability, less waste.
  • Weather
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can condensation be remedied?

A
  • Ventilation
  • An increase in air temperature.
  • Dehumidification.
  • Increase in surface temperature (insulation)
  • Avoid cold bridging.
  • Vapour barriers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a deleterious material?

A
  • Dangerous to health
  • Causes building failure
  • Environmentally damaging
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name some deleterious materials?

A
  • Asbestos
    -Lead
  • Hair plaster
  • Urea Formaldehyde
  • Sea dredged aggregates
  • Silica dust
  • Wood wool
  • Chlorides
  • High alumina cement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does condensation occur?

A

When air cools it can’t hold moisture, dew point will occur on colder surfaces below the dew point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How would you identify dry rot?

A

-Deep cracks running across grain (cuboidal)
-Mycelium growth
-Lemon tinge when fungus exposed to light.
- Timber will be brown and crumble.
- Spore dust
- Never outside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What causes rising damp?

A

Caused by faults or absence of DPC, can be exasperated by moisture content of the building, groundwater levels, leaks and flooding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How can damp be remedied?

A

By insertion of physical or injection of damp proof course.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What causes penetrative damp?

A

Can be caused by defective roof, cracks guttering etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What causes timber decay?

A

Wet rot, dry rot, insect attack.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How would you identify a cavity wall?

A

Age, cavities post 1920.
Brickwork type, stretcher with no header
measurements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How would you identify wet rot?

A
  • Dark brown staining to the timber
  • longitudinal cracking to the grain
  • damp musty smell
  • spongey feeling
  • timber crumbles when dry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What causes cracking to hardstandings?

A
  • Concrete, lack of day joints/expansion joints
    -base layer too thin
    -improper application
    -drainage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the minimum falls drainage should achieve?

A

1 in 40, 1 in 80 permissable (dependant on flow rates).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are common gutter defects?

A
  • Blocked
  • Cracked
  • Metal gutters can corrode
  • Sagging
  • Improper pitch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the limitations of using a moisture meter?

A

Regularly calibrate

20
Q

What are roof lights generally made of?

A

Polycarbonate

21
Q

What is dishing?

A

Usually occurs when something is overloaded, can be a floor

22
Q

What is a portal frame

A

Columns and rafters fixed at the haunch and ridge.

23
Q

How is a portal frame braced against lateral movements

A

Wind posts

24
Q

What foundations would you expect on a portal frame?

A

Piled or Pads at each column

25
Q

How should a cladding sheet be installed?

A

When installing roof sheets a lapping tape and mastic should be used at the overlap and a secondary seal should be installed before the fixing.

26
Q

How do roof lights display failure characteristics

A

Glass fibre becomes exposed
coating wears away
Discoloures UV
Become brittle
May become cracked

27
Q

What other types of movement

A

Thermal movement, due to expansion and contraction of building materials, in brickwork caused by lack of expansion joints in brickwork

28
Q

What are the BRE digest 251 cracking classifications?

A

0 Hairline less than 0.1mm no repair needed
1 Fine cracks, up to 1mm - normal decoration
2 Cracks easily filled up to 5mm
3 Cracks that require opening up, 5-15mm repoint
4 Extensive damage, 15-25mm break out and replace
5 Structural damage, 25mm+ may require major repairs

29
Q

What types of gutters are you aware of?

A

Gravity fed and siphonic

30
Q

How does a siphonic system work?

A

siphonic systems prevent air and debris getting in to speed up suction.

31
Q

How would you know if a roof sheet is fragile?

A

Red fixings

32
Q

Wha are common defects you would find on all periods of housing?

A

Over notching roofs
removal of chimney breast
provision of insulation
blocking air bricks
removal of load bearing walls
plating/removal of trees (heave)
Replacement windows

33
Q

What approved document deals with guttering

A

Part H

34
Q

How would you re point

A

Rake out mortar at least 2 times depth of joint

35
Q

What temperature should you pour concrete

A

3 degrees

36
Q

How do you test for concrete carbonation?

A

Fenofaileen test in situ, PH indicator turns pink if uncarbonated

37
Q

Name three types of movement to foundations.

A

Settlement - Caused by weight of the building, can be caused by soil conditions method of construction and poor compaction
Subsidence - Caused by soil beneath being unstable and shrinking downwards, can be caused by a loss of moisture in the soil, drains, trees.
Heave - Upwards movement of the ground can be caused by expansion of clay soils, water table, water in soil expands as it freezes.

38
Q

What defects would you associate with calcium silicate bricks?

A

Prone to shrinkage and expansion cracks, mortar needs to give.

39
Q

Explain cut edge corrosion

A

When cut in factory an exposed edge is left, capillary action causes water to sit on this edge. As the edge is exposed to elements it begins the process of oxidisation resulting in corrosion. Corrosion will spread across the metal. Once this corrodes back to the screw can cause roof collapse and leakage. Can be treated with a silicone based treatment, commonly found at eaves and overlaps.

40
Q

Common concrete defects?

A

-Concrete carbonation - corrosion of steel, steel expands and results in concrete breaking apart.
-HAC (High alumina cement) - Popular in 50/60s, used to strengthen concrete quickly.
-Chloride attack - Chloride additives used in 50/60s to speed drying time, increased corrosion in rebar, identified through pitting and steel corrosion.
- Sulphate attack - cause concrete to expand and contract, caused by sulphates in groundwater. leads to heave of slab and structural damage.
- Woodwool - when used as permanent shuttering can causes honeycombing and voids, therefore reduces fire resistance and loss of structural integrity.
-ASR - (concrete cancer) - concrete highly alkaline. alkaline reacts with silica and produces a gel. Gel takes in water and expands, cracking the concrete.

41
Q

What causes efflorescence

A

White crystalline deposit, moisture passes through material picks up sulphate and brings to surface.

42
Q

What does horizontal cracking through brick bed joint suggest?

A

was tie failure. Caused by…
- Exposure to moisture
- Poor galvanisation
- Poor workmanship

43
Q

How would you repair wall tie failure

A

helical reinforcement bar

44
Q

What other types of cracking do you see in buildings?

A

Lintel failure, triangular cracking above windows

45
Q

What is black spot mould?

A

Fungal growth caused by condensation

APC Technical (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions