Inspection Flashcards
Describe some differences between a reinstatement cost assessment inspection and a TDD inspection
RCA is for insurance purposes and looks to quantify the cost for reconstructing the building.
Technical Due Diligence is used for providing information on the risks, defects associated with a property and plan for maintenace requirements in the future.
What do you consider in a pre-inspection risk assessment
Prior to inspection, ensure you know the location of the subject property and can identify suitable parking. For health and safety reasons, make sure someone knows where you are and you adhere to lone working policies. Make sure your phone has enough power for the inspection .
What are the various forms of leak detection?
- Electronic leak detection
- Clearwater simulated rainfall test
- Dye Testing (Dyed water simulated rainfall)
What are the downsides of using BCIS cost information?
BCIS is based on average costs and can sometimes not be applicable for certain more unique situations.
- Data from BCIS is from an unknown provenance and therefore you cannot confirm its accuracy.
Why are accurate notes important for a dilapidations schedule?
Accurate notes are important as should the dispute end up in litigation, it may require these notes to be interrogated by expert witnesses.
What is a Day One Reinstatement Value?
Also known as the declared value it is the cost to rebuild the property of day 1 of the insurance cover.
What is concrete carbonation?
Concrete carbonation is when the CO2 in the atmosphere reacts with the concrete reducing its alkalinity. When PH level of concrete reaches 11pH passivating layer can be breached leading to corrosion of reinfocement.
Factors that determine timefrane for carbonation?
- Porpous or low cement content = quicker
- high cement content is slower
- depth of reinforcement
Min. depth of concrete cover for steel reinforcements?
Absolute min is 20mm however this will depend on its conditions and use. Refer to BS 8110 for more information.
How to measure the depth of Carbonation?
- using a phenolphthalein inidctor solution on a concrete core sample.
- if purple stained the concrete is not carbonated (acceptable PH)
- if mixture is colourless on the concrete carbonation has occured.
- tested areas should be left for 24 hrs before assessing
Prevention and repair to carbonation and corroded Steel reinforcements?
Prevention
- Anti carbonation coatings can be applied to the concrete, which prevent the ingress of CO2 for circa 10 yrs.
Remedial
- Should comply with BS EN 1504
- descale and clean corroded steel
- apply anti corrosison
replace missind and damage concrete using high cement to water ration
- apply any carbonation coating to all concrete
What is high chloride content in concrete?
High Chloride content can cause severe corrosion to reinforcements.
Chlorides can be present through:
- external deicing salts or seawater
- certain admixtures used for acceleration of curing
How do you test the chloride content of concrete/
Crushing a sample of concrete to a fine dust, extracting the chlroide with a nitric acid.
What are the acceptable levels of chloride content?
x<0.4% = low risk
0.4<x<1% = medium risk
x > 1% = high risk
What are the available remedial solutions to a high chloride content in concrete?
Depends on the extent of corrosion to the rebar, however:
- ELectrochemical chloride extraction (ECE) is a process that extracts or removes chloride ions from chloride-contaminated reinforced concrete structures. An electrical current is applied between the embedded steel and an external anode as a rehabilitation option to mitigate ongoing corrosion of the embedded steel.
- if extent of damage and corrosion is severe replacement of concrete may be required
