Building pathology Flashcards
- 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
- What are the typical defects that affect commercial premises 2. Describe how you would identify them and potential remedial actions?
What are the common defects associated with flat roofs?
What are the typical defects of a flat roof? What are the remedies?
Tell us about the methods of assessing flat roof defects you learned about?
What are the remedial measures for flat roof defects?
What should you take into account when deciding whether to repair or replace a flat roof?
You are asked to inspect a flat roof take us through the inspections process?
What is damp?
What types of damp are there?
What is a Speedy Carbide Meter?
How would you identify rising damp? What are the causes? How would you remedy it?
State and Describe 3 Remedies for Rising Damp.
How would you identify penetration damp? What are the causes? How would you remedy it?
What causes condensation within a premises? What are the symptoms? How would you remedy it??
What is a cold bridge?
How would you tell the difference between rising damp and condensation with a moisture meter
What ways could moisture enter the building? How would you differentiate between the different types?
You are inspecting a building and identify a number of cracks in the external wall take me through your thought process? (BRE 251)
What other sorts of cracks would you expect to see on a brick building and what might have caused them?
What are the common deleterious materials?
Summarise BRE 251
What is cut edge corrosion and why does it occur? What is the remedial for it?
What are the other typical defects on an industrial unit and why do these occur
(Forge Cottages) how did you know it was converted in the 1960s-1970s period?
What BRE good repair guides have you studied, can you explain these?
(Forge Cottages) how could the mortar fillet be faulty?
(Forge Cottages) what is timber decay? What type of decay was affecting the rafter? What was your recommended remedial action?
How do you use an electronic moisture meter?
What are the positives and negatives of an electronic moisture meter?
What other instruments are used in damp diagnosis?
(Forge Cottages) What caused the lack of ventilation? How can this be avoided?
What is WME?
(Forge Cottages) how did you know that condensation was affecting the roof space? What defects could a build up of condensation lead to?
What types of metal sheeting are used on commercial premises?
(Treadway) How could you tell the insulation was dated?
(Treadway) What thickness is modern insulation to a commercial roof?
(Treadway) What are some common defects with steel portal frames and how are they treated?
What are the typical metal cladding defects?
(Treadway) what caused the cementitious profiled sheeting to fail?
What are the typical stone cladding defects?
(Treadyway) Describe the construction process of upgrading a commercial roof.
(Treadyway) how could this be achieved during tenancy?
How would you identify penetrating damp? What are the causes? How would you remedy it?
Following damp, how long would you leave the brick / plaster to dry out before commencing work?
What causes discolouring at 450 x 900mm centres in a grid formation and how do you remedy it?
You are inspecting a building and identify a number of cracks in the external wall, take me through your thought process?
What other sorts of cracks would you expect to see on a brick building and what might have caused them?
Internal alterations - what are some considerations?
(BRE 251) what sizes of cracks are concern?
(BRE 251) walk me through the assessment process of BRE 251
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?
If there was stepped cracking on the corner of a building, what might have caused it?
What if the cracks were on concrete?
Crack beneath bay window and main wall - possible causes and remedies
What type of soil is susceptible to heave and what are the possible causes?
What type of soil is susceptible to subsidence and what are the possible causes?
What are the common soil types within the UK and what influence do they have on foundation design
Flank wall bulging full over its full height?
Foundations can subside or heave, name some reasons
What types of timber defects are there?
Describe the different types of rot and how you would recognise them
What are the remedial measures to dry / wet rot?
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?
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?
What are the remedial measures for dry rot?
Explain the life cycle of a rot?
Name some common insects that are known to attack timber? What remedial methods are available? What is the process of these measures?
How do you identify the presence of woodworm?
How do woodworms affect timber in buildings?
What is woodworm infestation likely to indicate?
Deflected timber floor in the early 19th century building. What methods are available to deal with this if the client requires a level floor?
A newly cast reinforced concrete slab is exhibiting crazing and cracking on its surface, possible causes and remedial methods?
Name the three types of asbestos and examples of where they are found in buildings?
What are Nickel Sulfide Inclusions?
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?
How does cavity wall tie failure present itself? How would you fix it?
What is nail fatigue?
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?
What are the stages of plastisol degredation?
Why does cut edge corrosion occur? What can happen if it is not treated? How can it be remediated?
What coatings are usually found on sheet metal? How can it break down?
What is Japanese knotweed?
What does it look like?
Why is it an issue?
Why is it particularly an issue for buildings and construction sites?
What legal restrictions are there in dealing with it?
How should it be dealt with?
Discuss the likely causes of a leaning chimney breasts and the remedial work.
What are the symptoms, methods of testing and treatment of Concrete Defects? (BRE Digest 405)
What are the symptoms, methods of testing and treatment of Chloride Attack? (BRE Digest 444)
What are the symptoms, methods of testing and treatment of Alkali Silica Reaction? (BRE Digest 330)
What are the symptoms, methods of testing and treatment of High Alumina Cement? (BRE digest 392)
What are the symptoms, methods of testing and treatment of RAAC concrete?
What are the symptoms, methods of testing and treatment of Sulphate Attack? (BRE Digest)
What is the cause, methods of testing and treatment of ‘Honey Combing’ (BRE Digest)
Summarise BRE Digest 361
(Trystings Close) - What is the difference between differential settlement and subsidence?
(Trystings Close) - What did you recommend next?
(Trystings Close) - Did you not believe this to be subsidence?
(Trystings Close) - Why does a mature Oak Tree have an affect on the movement / soil conditions?
(Trystings Close) - What guidance is there referring to presence of trees?
Name some defects that were applicable to the Georgian Period.
(Forge Cottages) How did you identify the building’s age?
(Forge Cottages) How could you identify that the sarking was impermeable?
How do you identify Japanese Knotweed and how is it treated?
Break down elemental / period defects: Victorian 1840 - 1900
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
Break down elemental / period defects: Victorian 1930 - 1940
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)
Break down elemental / period defects: Victorian 1960 - 1970
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
Break down elemental / period defects: Modern 1980 - Present
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
Break down elemental / period defects: Pre-1900
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.
