Building Pathology Flashcards
What are the different codes of lead and what are they used for?
- Code 3 - Soakers (1.32mm)
- Code 4 - Flashings and vertical cladding. All rounder/versatile (1.80mm)
- Code 5 - Flashings, flat roofing, valley gutters, dormers, canopies (2.24mm)
- Code 6 - Flashing / flat roofing
- Code 7 - Pitched roofs, valley gutters, dormers
- Code 8 - Flat roofing
What are the typical spacings for wall ties?
- Horizontal = 900mm
- Vertical = 450mm
What are the different types of DPC?
- Chemical
- PVC
- Lead
- Engineering Brick
What are some typical defects in modern buildings?
- Cut edge corrosion
- Flat roof issues
- Curtain walling detachment
- Failed gaskets
- Defective glazing panels
- Wall tie failure
- Lack of expansion joints
- Steel frame corrosion
- Concrete defects
What are steel fillers joists?
- Early form of concrete reinforcement typically used between 1880 - 1920.
What are the general distances between movement joints in external wall?
- Clay brickwork = 10 - 12m
- Lightweight concrete block = 6m
- Dense concrete block = 8m
- Parapet masonry wall = Half the above spacings and 1.5m from corners.
How can you tell if building is steel framed rather than concrete?
- Small column sizes with large span between.
What are the different types of beetle attack in timber and where are they found?
- Deathwatch = Southern / central England.
- Common Furniture = All across UK.
- House Langhorn = Surrey Berkshire and Hampshire.
How would you treat beetle attack?
- Injection with paste at regular intervals of wood (kills woodworm).
- Envelope treatment - prevents new larvae from boring into timber and prevents adults from leaving. Breaks life cycle of woodworm and causes woodworm to die out gradually.
- Remove wood if it had lost its integrity.
What are the different types of moisture meter?
- Electrical Resistance Meter = Two pin electrodes which are driven into the wood fibres and directly measure electrical resistance or conductivity.
- Dielectric = Incorporates two pads which serve as rubber electrodes that transmit and receive a signal when pressed into the wood substrate.
What else could use to test for moisture
- Carbide test.
Where would you usually find wet rot?
- Most commonly associated with serious leaks = failed plumbing, can also decay exterior.
Where would you usually find dry rot?
- Inside buildings (never attacks outside).
What is the Latin name for wet rot?
Serpula lacrymens.
What conditions do dry rot occur in?
- 20 - 40% timber Moisture Content.
- Temperature 0 - 26 Degrees.
What conditions do wet rot occur in?
- 45 - 60% moisture content.
- Temperature - 30 to + 40 degrees.
What is dry rots effect on timber?
Large cuboidal cracking.
What is wet rots effect on timber?
Small cuboidal cracking. May leave thin layer of sound timber. Affected wood becomes dark brown.
What were your long and short-term remedial measurers you reported to resolve the leak within the industrial unit?
Why can skylights be a source of weakness within a roof?
Any opening is a source of weakness.
What typical defects do you find with Georgian properties?
- timber defects
- damp
- water ingress via chimneys
If you identified significant issues with glazing, would you recommend any further investigations to be undertaken?
- Further investigations from a glazing specialist
Why did you advise the client to remove the asphalt and not propose an overlay system?
- No, I recommeded an EPDM overlay
What were the benefits of removing the asphalt when comparing to overlaying?
Load to the roof.
