Building pathology

Question 1

1. Give me an example of historical construction methods of residential premises in London 2. What are the typical defects that occur 3. what are potential remedial actions

Question 2

1. What are the typical defects that affect commercial premises 2. Describe how you would identify them and potential remedial actions?

Question 3

What are the common defects associated with flat roofs?

Question 4

What are the typical defects of a flat roof? What are the remedies?

Question 5

Tell us about the methods of assessing flat roof defects you learned about?

Question 6

What are the remedial measures for flat roof defects?

Question 7

What should you take into account when deciding whether to repair or replace a flat roof?

Question 8

You are asked to inspect a flat roof take us through the inspections process?

Question 9

What is damp?

Question 10

What types of damp are there?

Question 11

What is a Speedy Carbide Meter?

Question 12

How would you identify rising damp? What are the causes? How would you remedy it?

Question 13

State and Describe 3 Remedies for Rising Damp.

Question 14

How would you identify penetration damp? What are the causes? How would you remedy it?

Question 15

What causes condensation within a premises? What are the symptoms? How would you remedy it??

Question 16

What is a cold bridge?

Question 17

How would you tell the difference between rising damp and condensation with a moisture meter

Question 18

What ways could moisture enter the building? How would you differentiate between the different types?

Question 19

You are inspecting a building and identify a number of cracks in the external wall take me through your thought process? (BRE 251)

Question 20

What other sorts of cracks would you expect to see on a brick building and what might have caused them?

Question 21

What are the common deleterious materials?

Question 22

Summarise BRE 251

Question 23

What is cut edge corrosion and why does it occur? What is the remedial for it?

Question 24

What are the other typical defects on an industrial unit and why do these occur

Question 25

(Forge Cottages) how did you know it was converted in the 1960s-1970s period?

Question 26

What BRE good repair guides have you studied, can you explain these?

Question 27

(Forge Cottages) how could the mortar fillet be faulty?

Question 28

(Forge Cottages) what is timber decay? What type of decay was affecting the rafter? What was your recommended remedial action?

Question 29

How do you use an electronic moisture meter?

Question 30

What are the positives and negatives of an electronic moisture meter?

Question 31

What other instruments are used in damp diagnosis?

Question 32

(Forge Cottages) What caused the lack of ventilation? How can this be avoided?

Question 33

What is WME?

Question 34

(Forge Cottages) how did you know that condensation was affecting the roof space? What defects could a build up of condensation lead to?

Question 35

What types of metal sheeting are used on commercial premises?

Question 36

(Treadway) How could you tell the insulation was dated?

Question 37

(Treadway) What thickness is modern insulation to a commercial roof?

Question 38

(Treadway) What are some common defects with steel portal frames and how are they treated?

Question 39

What are the typical metal cladding defects?

Question 40

(Treadway) what caused the cementitious profiled sheeting to fail?

Question 42

What are the typical stone cladding defects?

Question 43

(Treadyway) Describe the construction process of upgrading a commercial roof.

Question 44

(Treadyway) how could this be achieved during tenancy?

Question 45

How would you identify penetrating damp? What are the causes? How would you remedy it?

Question 46

Following damp, how long would you leave the brick / plaster to dry out before commencing work?

Question 47

What causes discolouring at 450 x 900mm centres in a grid formation and how do you remedy it?

Question 48

You are inspecting a building and identify a number of cracks in the external wall, take me through your thought process?

Question 49

What other sorts of cracks would you expect to see on a brick building and what might have caused them?

Question 50

Internal alterations - what are some considerations?

Question 51

(BRE 251) what sizes of cracks are concern?

Question 52

(BRE 251) walk me through the assessment process of BRE 251

Question 53

Please describe the directional pattern of a crack caused by expansion of brickwork to a wall. Would the cracking be evenly spaced throughout or increase/decrease in width at one end?

Question 54

If there was stepped cracking on the corner of a building, what might have caused it?

Question 55

What if the cracks were on concrete?

Question 56

Crack beneath bay window and main wall - possible causes and remedies

Question 57

What type of soil is susceptible to heave and what are the possible causes?

Question 58

What type of soil is susceptible to subsidence and what are the possible causes?

Question 59

What are the common soil types within the UK and what influence do they have on foundation design

Question 60

Flank wall bulging full over its full height?

Question 61

Foundations can subside or heave, name some reasons

Question 62

What types of timber defects are there?

Question 63

Describe the different types of rot and how you would recognise them

Question 64

What are the remedial measures to dry / wet rot?

Question 65

Ends of the joists in a timber floor built in an external wall have been seriously affected by dry rot. How will you recognise this type of rot and what action would you take to resolve the problem?

Question 66

The ends of the joists in a timber floor built in an external wall have been seriously affected by wet rot. How will you recognise this type of rot and what action would you take to resolve the problem?

Question 67

What are the remedial measures for dry rot?

Question 68

Explain the life cycle of a rot?

Question 69

Name some common insects that are known to attack timber? What remedial methods are available? What is the process of these measures?

Question 70

How do you identify the presence of woodworm?

Question 71

How do woodworms affect timber in buildings?

Question 72

What is woodworm infestation likely to indicate?

Question 73

Deflected timber floor in the early 19th century building. What methods are available to deal with this if the client requires a level floor?

Question 74

A newly cast reinforced concrete slab is exhibiting crazing and cracking on its surface, possible causes and remedial methods?

Question 75

Name the three types of asbestos and examples of where they are found in buildings?

Question 76

What are Nickel Sulfide Inclusions?

Question 77

You find a leak at high level on a first floor of a 2 storey building constructed with traditional cavity wall construction. Please outline the process which you would go through in assessing the cause for the defect. Also, what are the potential causes of such a defect?

Question 78

How does cavity wall tie failure present itself? How would you fix it?

Question 79

What is nail fatigue?

Question 80

What would be the associated problems and defects with a ‘crinkly tin’ shed approximately 15 years old? What defects might you find with profiled steel cladding?

Question 81

What are the stages of plastisol degredation?

Question 82

Why does cut edge corrosion occur? What can happen if it is not treated? How can it be remediated?

Question 83

What coatings are usually found on sheet metal? How can it break down?

Question 84

What is Japanese knotweed?

Question 85

What does it look like?

Question 86

Why is it an issue?

Question 87

Why is it particularly an issue for buildings and construction sites?

Question 88

What legal restrictions are there in dealing with it?

Question 89

How should it be dealt with?

Question 90

Discuss the likely causes of a leaning chimney breasts and the remedial work.

Question 91

What are the symptoms, methods of testing and treatment of Concrete Defects? (BRE Digest 405)

Question 92

What are the symptoms, methods of testing and treatment of Chloride Attack? (BRE Digest 444)

Question 93

What are the symptoms, methods of testing and treatment of Alkali Silica Reaction? (BRE Digest 330)

Question 94

What are the symptoms, methods of testing and treatment of High Alumina Cement? (BRE digest 392)

Question 95

What are the symptoms, methods of testing and treatment of RAAC concrete?

Question 96

What are the symptoms, methods of testing and treatment of Sulphate Attack? (BRE Digest)

Question 97

What is the cause, methods of testing and treatment of ‘Honey Combing’ (BRE Digest)

Question 98

Summarise BRE Digest 361

Question 99

(Trystings Close) - What is the difference between differential settlement and subsidence?

Question 100

(Trystings Close) - What did you recommend next?

Question 101

(Trystings Close) - Did you not believe this to be subsidence?

Question 102

(Trystings Close) - Why does a mature Oak Tree have an affect on the movement / soil conditions?

Question 103

(Trystings Close) - What guidance is there referring to presence of trees?

Question 104

Name some defects that were applicable to the Georgian Period.

Question 105

(Forge Cottages) How did you identify the building’s age?

Question 106

(Forge Cottages) How could you identify that the sarking was impermeable?

Question 107

How do you identify Japanese Knotweed and how is it treated?

Question 108

Break down elemental / period defects: Victorian 1840 - 1900

Answer 108

Roof:

• Typically incorporate traditionally cut timber rafters. These were not designed to modern standards but sizes can vary.
• Typically tiles comprise clay or slate.
• Over time, these can deteriorate. Clay tiles can corrode, and slate tiles can delaminate and crack. Further to this, the nails used to nail the slate tiles can rust (nail sickness).
• Sarking felt was not used historically, meaning that the roof space is susceptible to moisture ingress.
• The battens over time can decay due to this.
• Over time, roof upgrades include impermeable sarking felt. This is a non-breathable membrane
• This means that the rate of evaporation of moisture within the roof space will be less.
• Provision of insulation can prevent ventilation (typically afforded at eaves)
• This can lead to a increase in humidity which can accelerate timber decay.
• Chimneys can be affected by sulphate attack - leading to leaning chimney stacks.

Walls:

• No DPC
• Lack of lateral restraint, timber joists typically spanning from front to back, no lateral restraint for the roof to tie into the wall
• Stairs up to gable end provide this tie - relocation of the stairs can be an issue.
• Issues where cement based renders are applied to masonry walls, these were designed to be ‘breathable’, accepting that the wall will become wet but also dry out (as opposed to sealed modern construction)
• Timber deflection - old timber elements such as timber lintels can deflect over time naturally due to the stress applied from the masonry elements. This can lead to cracking in walls
• Rotting timber elements
• Differential movement between bay windows / main wall structure abutment.

Floors:
- Over notching of floor joists
- Blocked air bricks / poor ventilation of sub floor void
- Built in timbers to walls leading to decay

Deleterious Materials:
- Lead paint
- Lead pipework
- Asbestos (refurbishment)
- Animal hair (anthrax

Timber window deterioration

Question 109

Break down elemental / period defects: Victorian 1930 - 1940

Answer 109

Walls:

• Cavity walls were beginning to be used.
• Lack of cavity wall insulation / shallow cavity, debris within cavity leading to interstitial condensation
• Retrofit insulation can cause issues
• Wall tie corrosion
• Cementitious Renders- Introduction of prefabrication (system builds)
• Crittal Windows

Deleterious Materials
- Asbestos
- Mundic (Pyrites)

Question 110

Break down elemental / period defects: Victorian 1960 - 1970

Answer 110

Roof:

• Wood wool / and Stramit board
• HAC / RAAC
• Asbestos
• Cut edge corrosion
• Gang nailed truss roofs

Walls:

• Precast / cast in-situ concrete superstructures
• Carbonation
• Reinforcement corrosion
• Concrete boot lintels - can rotate due to load
• Brick slips fixed to concrete frame - thermal movement
• Calcium silicate bricks
• Mosaic tiles
• Calcium chloride additives - corrosion
• GRC cladding

Floors
- Woodwool
- Lack of movement joints
- Made ground (concrete slab)

Deleterious Materials
- Asbestos
- HAC
- Calcium chloride
- Nickel sulphide reaction

Question 111

Break down elemental / period defects: Modern 1980 - Present

Answer 111

Roofs:

• Cut edge corrosion
• Defective flat roofs
• Poor Insulation
  -Pitting
  -Curtain walling / rainscreen cladding detachment
• Symphonic drainage systems

Walls
- Rotation of short returns - insufficient restraint
- Lack of expansion joints

Walls / Cladding

• Composite cladding - fire risk
• Use of formaldehyde in injected foam insulation (carcinogenic)
• Nickel sulphide
• Lack of expansion joints
• Deterioration of plastisol / PVF2 finishes

Deleterious materials
Asbestos up to 1999-2000
Woodwool

Question 112

Break down elemental / period defects: Pre-1900

Answer 112

Bridge / failed lack of DPC - rising damp, penetrating damp, efflorescence, timber decay

Poor ventilation of suspended timber floor / roof space - timber decay

Poorly fitted sash windows - draughts, difficult operation, timber decay, poor security,

Leaking services - penetrating damp, efflorescence, timber decay, damaged internal finishes

Modern concrete roof tiles - Overloading, roof spread pushing walls out of plumb and structural instability

Removal of chimney breasts

Lack of lateral restraint

Concrete / hard mortar - spalling masonry

Failure of brick / timber lintels - cracking / distortion of the masonry

Lead paint / pipework - health concerns

Removal of internal load bearing partitions - bowing floors, risk of collapse

Differential settlement at bay window - shallow foundations at bay leading to differential cracking

Insect attack - flight holes, loss of structural strength depending on beetle type and signifiance.