Risk assessing a loft for Legionella
When was the last time you went into your loft? Beyond opening the hatch to stow something away or retrieve an item, it’s fair to say that most people spend little or no time actually looking around the loft and doing a proper inspection, unless there’s a good reason for it (such as a leaking roof). And if you’re a landlord, I’d bet that you may NEVER have been into the attic of your rental property. Here’s a salutary tale which may just prompt you to get out your ladder and spend some time up in the roof space.
One of our engineers recently bought a new house which had previously been lived in by an elderly lady for many years. As a result, the property is in need of some updating so Tony and his wife have been getting stuck in to the DIY, starting in the loft with the removal of a chimney. While in the attic pulling out bricks from the chinmey breast, Tony took the opportunity to have a good look around and was unpleasantly surprised by the amount of corpses he found; birds, rats and mice in varying states of decay and mummification, along with plenty of evidence of them having been in residence for some time. Considering the roof was in good condition, he was shocked at how much wildlife had penetrated the building.
And where there’s wildlife, there’s potential contamination of the water supply, not to mention plenty of food for Legionella bacteria to feed on. So Tony’s next inspection was of the water tank. Luckily his had a securely-fitted lid, but looking inside it he found a large amount of sludgy sediment in the bottom, which makes it a very welcoming environment for Legionella bacteria.
Needless to say, the loft has now been cleared out and the water tank has been thoroughly cleaned, but here are some tips on how to undertake a loft inspection as part of controlling the risk of Legionella.
Go into the loft regularly (at least once a year) and have a good look around. Use a powerful torch and make sure you cover the whole loft, not just the bits you can see from peering through the hatch
Check on all pipework (particularly the joints) to look for signs of rust or corrosion. Are there any dead legs or blind ends?
Look at the water tank. Does the lid fit tightly? Is it clean inside? Is there any corrosion, leakages or rust? Give it a good clean if there is dirt, slime or sediment and make sure you replace the lid properly when you’ve finished
Is there any evidence of animal infestation? Birds and rodents bring in disease and can damage pipework, potentially opening up the water system to contamination
What is the temperature like in the loft? Heat rises so roof spaces can get very warm. Check the temperature of the water stored in the tank too. Legionella bacteria thrives between 20°C and 50°C, so make sure it’s outside this range (below 20°C it will lie dormant; above 50°C it’s killed off).
If you make sure your loft is kept clean and safe, paying particular attention to the plumbing system, you will be significantly reducing the risk of Legionella.