Building Pathology

Question 1

Provide examples of wood boring insects

Answer 1

Common Furniture Beetle
Deathwatch Beetle
Wood-boring Weevil

Question 2

What are some common symptoms of insect infestation in timber?

Answer 2

Flight holes, frass and weak or crumbling timber.

Question 3

What are the types of damp?

Answer 3

Rising damp, penetrating damp and condensation.

Question 4

What are the common causes of cracking?

Answer 4

Settlement, subsidence, heave, thermal movement.

Question 5

Explain how the passage of moisture is different for solid walled buildings and cavity walled buildings

Answer 5

In solid walled buildings, water can penetrate directly from outside to inside and the wetting and drying process is normal as long as there isn’t anything trapping the moisture in either side. With cavity walled buildings there is a cavity which acts as a barrier and any water which penetrates the external leaf is carried back externally through weep vents.

Question 6

How do you diagnose the type of damp present to a property?

Answer 6

I would assess the symptoms present to ascertain the likely cause and then follow the trail of suspicion to confirm this where possible.

Question 7

What are the symptoms and causes of condensation?

Answer 7

Symptoms include mould growth and visible water droplets on windows or external walls. Can be caused by excess moisture internally, poor heating and ventilation.

Question 8

What are the symptoms and causes of rising damp?

Answer 8

Tide marks up to a metre high, efflorescence, peeling paint at low level. Causes would be lack of damp proof course or damp proof cause that is bridge or damaged.

Question 9

What are the symptoms and causes of penetrating damp?

Answer 9

Irregular shaped damp patches on walls or ceilings. Causes can be damaged rainwater goods, damaged roof covering, deteriorated mortar pointing, poor flashing details.

Question 10

What equipment would you take for a survey?

Answer 10

Would depend on the type of survey but paper and pen or iPad, camera, damp meter, drain keys, ladder, pole camera.

Question 11

What RICS documentation is available for condition surveys of buildings?

Answer 11

Technical Due Diligence of Commercial Property Professional Standard
Surveying assets in the built environment
Home Survey Standards for residential.

Question 12

What’s a borescope? What are its limitations?

Answer 12

An inspection tool with an extendable camera which is connected to a screen allowing you to see into difficult to reach places such as wall cavities. Limitations include poor lighting, limited field of view and image quality.

Question 13

What’s a Hygrometer? What are its limitations?

Answer 13

An instrument which measures the level of humidity or moisture vapour in the air. Limitations include generalised readings so can’t pinpoint exact locations, can give false readings if contaminated with dust or dirt and cheaper models may not provide particularly accurate readings.

Question 14

What’s a Protimeter? What are its limitations?

Answer 14

An instrument which measures the moisture levels of a material and provides a wood moisture equivalent reading. Limitations include false readings due to presence of salts, surface readings may underestimate the moisture content, typically calibrated for wood so not entirely accurate for other materials.

Question 15

Why did you produce a sketch during your survey of the retail unit in Hinckley?

Answer 15

So that I could mark on the layout where defects where identified and it assisted with the location of possible causes of defects. An example being damp and nearby downpipes or potential RAAC to an upstairs ceiling corresponding with a flat roof extension.

Question 16

What are some of the defects you identified during you condition survey in Hinckley?

Answer 16

Vegetation growth to the flat roof
Old security safe which could contain asbestos
pipework penetrations to adjacent buildings didn’t have any fire stopping

Question 17

Why can blocked drains cause cracking?

Answer 17

Water from a damaged drain can erode the surrounding soil around the building’s foundations. Also if the soil is claylike then increased moisture could cause soil to swell and cause cracking due to heave.

Question 18

What is RAAC?

Answer 18

Reinforced Autoclaved Aerated Concrete — a lightweight, precast concrete material commonly used in buildings from the 1950s to the 1990s.

Question 19

Why is RAAC bad?

Answer 19

Weaker than traditional concrete and is prone to sudden failure.

Question 20

How would you identify RAAC?

Answer 20

Aerated texture which looks bubbly, no course aggregates present, greyish-white colour, typically 600m wide rectangular planks with chamfered edges.

Question 21

Why did you feel it necessary to contact the client straight away upon discovering the RAAC, instead of just issuing them with the report in due course like you usually would?

Answer 21

Because RAAC can fail suddenly so this would not only be a health & safety risk to anyone entering the property but could cause substantial damage to the property,

Question 22

What are some of the ways that water can enter a building?

Question 23

Why is damp within a building problematic?

Question 24

How do you record your on-site findings during a survey?

Answer 24

I produce a layout sketch, take photographs and make written site notes. I will also sometimes take measurements.

Question 25

How would you determine whether timber is suffering from wet or dry rot?

Answer 25

The location and moisture content of the timber. If it's outside and 40%+ then it's likely to be wet rot, if it's inside and between 20-40% it's likely to be dry rot.

Question 26

What guidance is available for surveyors undertaking damp surveys?

Question 27

What RICS documentation is there regarding damp surveys?

Question 28

What are the common causes of diagonal cracks within buildings?

Question 29

How would you assess the severity of a crack?

Answer 29

I would use BRE Digest 251 to categorise the crack severity based upon the width of the crack.

Question 30

If a crack continues through a DPC, what does this indicate?

Answer 30

This would suggest a more serious structural issue than a simple cosmetic crack so likely to be subsidence or

Question 31

How would you monitor cracking in a building?

Answer 31

Install a tell-tale and record the change in movement regularly over a set period of time. For example monthly recordings over the space of a year to include for all seasons.

Question 32

Explain how you assessed the cause of the cracking at IOSH?

Answer 32

So firstly I inspected the appearance and location of the cracks internally to assess what the likely causes could be. I then followed the trail of suspicion and identified large trees in close proximity.

Question 33

Explain your on-site method / approach during the damp and mould surveys you undertook?

Question 34

Why did you use a borescope during your damp and mould surveys?

Answer 34

I used a borescope to assess whether cavity wall insulation was present to the properties as lack of insulation can contribute towards condensation.

Question 35

Why did you use a Protimeter during your damp and mould surveys?

Answer 35

I used a protimeter to assess the pattern of damp. For example, whether the readings continued to display as high up to a height of 1 metre or if damp generally instead of a localised area it could indicate condensation.

Question 36

Provide examples of concrete defects?

Answer 36

Chemical attacks such carbonation, sulphate attack and chloride attack.

Question 37

Summarise BRE Digest 299 - Dry rot: its recognition and control

Question 38

Summarise BRE Digest 251 - Assessment of damage in low-rise buildings

Question 39

Summarise BRE Report 453 - Recognising wood rot and insect damage in buildings

Question 40

Summarise BRE Report 292 - Cracking in buildings

Question 41

Summarise CPD 12 2022: Movement in brickwork