FREE PICK UP on all Testing Kits.


Old & Refurbished Buildings

6 Item(s)

per page

Grid  List 

Set Descending Direction

6 Item(s)

per page

Grid  List 

Set Descending Direction


Legionella test kits for Old & Refurbished Buildings

Old Buildings

The older the building, the higher the risk since there is a greater chance of deadlegs, old metal pipes, meandering pipe runs, no recirculation of hot water etc.

A building that is 200 years old has probably had 5-10 major refurbishments, in many cases this increases the risk rather than minimising it, see below.

Refurbished Buildings

During refurbishment the water will be isolated for days or weeks allowing bacteria to multiply. Some pipework will no longer be required, often it is just capped off rather than removed – especially if it will be later be hidden beneath floors or between false walls. These pipes become deadlegs, the water within them is trapped and stagnates. The temperature will allow legionella to slowly multiply as the ambient temperature of most buildings is just above 20°C.

Disinfecting the building offers only a temporary reduction in legionella concentrations since disinfectants cannot permeate the whole length of a deadleg. After a few weeks some of the legionella will migrate to the open end of the deadleg and be swept along with the flow, allowing the bacteria to reach all parts of the building once more.

In these situations it is virtually impossible to eradicate the bacteria, so procedures need to be put in place to manage the concentration of legionella. These procedures may include temperature control or biocide additions, either way, more frequent legionella testing will be necessary to monitor the effectiveness of the regime.


  • Management of Health & Safety at Work Regulations 1999
  • Control of Substances Hazardous to Health Regulations 1999
  • Health & Safety at Work Act 1974


HSG274 Legionnaires’ disease: Technical guidance:-

  • Part 2: The control of legionella bacteria in hot & cold water systems

HSE- Legionnaires’ disease A guide for employers

Help, Share, Contact

Sign In

Forgot your password?

Create an account

  • View order history
  • Download test certificates
  • View subscriptions