As part of UK Radon Awareness Week, we are encouraging homeowners and employers to test their buildings for radon. But with several different types of radon detectors, test kits and monitors on the market, which should you choose? Read on to find out more about the various ways of testing for radon including information on how much radon testing costs and how long a radon test takes.
Passive Radon Detectors
The most commonly used type of radon detector used in the UK is a passive detector, comprising a small domed case containing a special lens. These detectors work by allowing air in the property to pass through the detectors and over the lens, where the radioactive radon particles will make microscopic indentations (or etches) on the lens. The detectors must be sent to a validated laboratory for analysis, where the lens will be developed and calculations made as to the level of radon it has been exposed to.
As radon levels fluctuate constantly, the most accurate results from any type of radon test are obtained when the test is performed over a long period of time. It is recommended that passive radon detectors are left in place for a period of three months before being returned to a laboratory for analysis.
In certain situations where a faster result is required, for example during a property transaction, a screening test can be performed using passive radon detectors left in place for 10 days.
Some important things to note about passive radon detectors are:
- The detector must be left in one place for the duration of the test. It is advisable to always use more than one detector per property as radon levels can vary. In an average home, one detector is usually placed in a living room and one in a bedroom.
- Passive detectors are not reusable; they can only be used and analysed once.
- The detector casing must never be opened as this will invalidate the test and the laboratory will not be able to process any results
- The detectors do not have any sort of display – they are completely passive (rather than active) and must be sent to a laboratory for analysis
- As the detectors need processing in a laboratory, you will need to factor in the additional time (usually around two weeks) to obtain the result
Price guide: £42.00 for a pack of two 3-month detectors or £49.20 for a pack of two 10-day screening detectors (including laboratory analysis & reporting, VAT and post & packing)
Digital Radon Monitor
Digital radon monitors actively detect and analyse concentrations of radon within a building and display this on a screen. There are several brands of digital monitors available, ranging from basic models for homeowners to sophisticated pieces of equipment designed to be used by radon professionals. One of the most popular consumer models available is the Airthings Corentium Home detector, formerly known as the Canary Radon Monitor. This battery-operated device is a very simple to use and displays both short term and long term average readings. A professional version is also available, which allows users to download results to a computer and produce a range of reports. Another digital monitor which is often used by radon professionals is the RadonAway RS800, which records hourly radon readings as well as environmental factors such as temperature and relative humidity.
Some important things to note about digital radon monitors are:
- The monitor must be left in one place for the duration of the test, however once the test period is complete and the results have been noted the monitor can be reset and moved to another test location.
- With many models, the results will be displayed on the screen and therefore visible to building users, which may not always be desirable. Some monitors have an option to disable the screen for this reason.
- In certain situations, a formal report from a validated laboratory may be required as proof of radon testing, therefore a digital monitor may not be appropriate.
- These monitors will not give an instant result and to obtain a reliable result should normally be left in place for 7 days or more before reliance is placed on the readings.
Price guide: £219.00 for an Airthings Corentium Home detector (Canary) or £3080.00 for RadonAway RS800i (including VAT and postage & packing)
Radon Grab Sampler
A grab sampler is useful for determining a pattern of radon readings within a property however should never be used as means of assessing the actual radon level in the building or to decide whether any action is required. Radon levels fluctuate constantly, therefore a snapshot of the radon level over just a few minutes does not provide enough information to assess what the average radon concentration in the property is. Instead, they are typically used as a tool to aid the design of a radon mitigation system once another form of testing has identified that works are required to reduce the indoor radon level. A radon professional may take a series of grab samplers throughout the building over a short period of time to gain a picture of where peak levels are, indicating a particular source or pathway that must be remedied.
The RadonAway GM1-2 can be used to take a radon grab sample over a 6 minute period, and the results are displayed on the unit. Samples are usually taken from within the room, however occasionally a radon professional may use the sampling tube to take a measurement from a suspected pathway, such as behind a dry lining or cavity drain membrane.
Some important things to note about grab samplers are:
- Radon grab samplers should only be used by professionals with the necessary expertise to interpret the results
- Grab samplers should never be used as the primary method of testing, rather as a diagnostic aid
- A series of grab samples can be very beneficial when designing a radon mitigation system, and should result in optimum performance of such a system
Price guide: £1574.00 for a RadonAway GM1-2 (including VAT and postage & packing) or Contact Us for a quotation for a diagnostic survey – price depends on property location & size