Case Study/Sum of exp Flashcards
How did you determine that the windows and cladding were not the source of water ingress?
I examined the sealants around the window head and these were all in order
The soffit areas were sheltered, dry and joints appeared in order
to cladding sections, no areas were missing and all flashing was present
What are some common flat roof defects?
Singly Ply
Blistering
-Moisture trapped beneath the roof surface caused it to detach from the surface below. When hot the air and moisture expands stretching the membrane
Thermal Movement
- Overtime single ply membrane can shrink, become brittle and loose elasticity.
this can cause stress to seams and flashings.
Excessive foot and equipment traffic
- May compress the insulation and cause additional stresses
- Can pierce the membrane
Asphalt
- UV degradation which pulls the bitumen out of the asphalt causing it to slump and crack.
What are the methods of assessing flat rood defects?
Electronic leak detection
- electric field is created on the dampened surface which is then earthed within the building (ie. leaking area)
Thermographic examination
- The thermographic image will highlight areas of moisture retained within the roof
Why did you recommend replacing the flat roof compared to other options?
3 reasons
The roof contained a number of patch repairs which made the substrate uneven.
there wasn’t much M&E so wouldn’t have been difficult to apply
Removing the roof covering would have allowed access to the insulation which was likely damaged due to water ingress.
What considerations should you take into account when deciding to replace a flat roof?
It’s age, life expectancy and overall condition
If defects are widespread or localised
clients intentions for the building, disruption and budget
How did you identify it was penetrating damp to the basement areas?
The decoration was peeling to walls only, unlikely to be a condensation issue
high level of efflorescence
Penetrating damp to basements on Union street is a known issue.
What is damp?
Damp refers to the presence of excess moisture in a the structure of a building. can lead to both structural and health problems.
3 main types of damp:
Condensation
- Which is when warm moist air comes into contact with a colder surface like a wall or window
Rising damp
- is caused by ground water moving up through a wall through capillary action.
- this is considered rare and often mis-diagnosed.
Penetrating damp
- is moisture that penetrates through the fabric of a building from the outside.
Can you explain the function of tanking and integrated drainage?
Tanking is a waterproofing method used in basements to prevent water ingress.
it involves applying a waterproof barrier such as cementitious coating, bitumen coating or liquid coating, to the internal or external surfaces of the basement which creates a tank like seal to prevent water penetration.
An integrated drainage channel is a system designed to re-direct water that has entered the basement.
It typically includes a network of channel or pipes to collect water and direct it to a sump pump.
Can you tell me what cut edge corrosion is and how it is treated
Cut edge corrosion is a common issue that affects aged metal profile roofs predominately around the sheet laps and sheet ends.
When the cladding sheets are cut to size the ends become more vulnerable to corrosion.
when corrosion occurs the surrounding coating de-laminates and peels back from the sheet age.
the exposed surface eventually becomes perforated
Treatment includes:
-preparing surface
-Applying sealant to joint
- Applying water proof over layer (usually 2)
Can you tell me some common defect in historical properties?
Damp
Structural movement
-Subsidence
- Heave
- Lintel failure
Timber defects
- Board boring insects
- fungal decay
Stone decay
- Delamination
- Unsympathetic additions
Roof defects
- Nail sickness
- Roof Spread
What is a siphonic outlets
Is a drainage system that does not allow air into the system.
this allows for smaller diameter down pipes
