When can moisture levels be regarded as ‘safe’ in materials:
When a resistance meter reading of less than 18% is observed
In what order would you triage contents damaged by water?
- Consider what is urgent to prevent secondary damage
- BER
- Items not at immediate risk of further damage
Where could hidden water damage in buildings lie?
- Water trapped behind panels/pipe boxing
- Water in floor insulation or void
- Water behind impermeable materials eg tiles
- Water can track around the edges of carpet grippers and soak carpets in another part of the room.
Use moisture meter to identify items at risk
What are the four categories of water damage, identified by the source of the water?
- Clean water
- Grey water
- Black water
- Red water
Describe ‘clean’ water
Directly from plumbing or when connecting to an appliance (not waste water coming from the appliance)
Describe ‘grey’ water
Low level of contamination eg from a washing machine outlet or fish tank
Grey water may turn to black over time due to microbial growth.
Describe ‘black’ water
Contaminated with sewage or storm water.
Black water is a serious health risk if not decontaminated.
Describe ‘red’ water
Contaminated with fuel
What should be your first action/priority when dealing with a water damaged property?
Extract water & reduce humidity
Name four ways in which water be extracted when dealing with a buildings claim for an escape of water?
- Release water in plasterboard ceilings by punching 10mm hole and releasing into buckets
- Extract/pump bulk water
- Use a weighted vaccum on carpets
- Use a submersible pump or wet vac
What do you need to be mindful of when removing deep water in basements?
Do not remove more than 1 metre per day due to hydrostatic pressure difference which could cause structural damage.
What you should consider in relation to water movement when dealing with a vertical leak?
Eg an escape of water from a boiler in the loft
Water can move horizontally via ducting, pipework and cable runs. Some floors could be by-passed altogether via ducting.
How long does it take for bacteria to double?
20 minutes.
100 becomes 1.5million in 5 hours!
Does water vapour move to higher or lower pressure areas?
Lower pressure
How would you decontaminate a property affected by black water?
- Bulk contamination-shovel, pump or liquid vacuum (& dispose in accordance with water authority requirements)
- Flush surfaces with clean water & vacuum extract
- Follow with alkaline detergent & a further rinse
- Skirtings & plasterboard may require removal
- Quality assess to check clean is sufficient
- Sanitising agent applied in accordance with COSHH risk assessment
Possibly use bactericides in water.
What steps would you take to reduce high humidity?
- Extract laying water
- Ventilate to outside
- Use dehumidifiers
- Heat/introduce low RH air
(point 4. increases the capacity of air to assist drying)
Why should you avoid using air blowers in the first hours/days after a water damage incident?
Without adequate humidity control the increased water vapour will cause secondary damage.
