Wiltshire is rich with Celtic history, with its plains being home to Stonehenge, the mysterious stone circle believed to date back to 3000 BC. Parts of the county are also classified as radon Affected Areas, as a client discovered when they were in the process of buying a property in a popular market town.
Set over three storeys, the relatively modern three storey home included a lower ground floor with an earth retaining internal wall.
Knowing that this increased the likelihood of the property being affected by radon, our client got in touch to request short-term testing to assess the situation.
Radon levels fluctuate constantly so it is preferable to carry out a test over several months in order to obtain an average reading.
However, during property transactions, it is important to avoid stalling or even breaking the chain so for speed, a short-term screening test can be carried out to provide an indication as to whether high radon concentrations are likely to be a problem.
Radon Testing Carried Out At Wiltshire Property
Passive radon detectors are placed in the property for a period of at least 10 days before being returned for fast-track laboratory analysis and results reporting.
The detectors were sent via the estate agents for the vendor to place and subsequent laboratory analysis showed levels of 192 Bq/m3 in the ground floor living room and 158 Bq/m3 in the lower ground floor reception room.
The testing was carried out during late Spring so PropertECO advised that the annual average concentration was likely to be at or around the action level of 200 Bq/m3 and certainly exceed the target level of 100 Bq/m3.
Mitigation Works in Wiltshire
The client was keen for radon mitigation work to be undertaken and so asked PropertECO to conduct a survey. Our surveyor visited the property and further grab sample profiling was carried out using a RadStar GM1-2 to obtain a pattern of readings.
This unique diagnostic aid is a specialist piece of kit designed for radon professionals to provide comparative readings across the footprint of a property to ascertain any particular points of ingress, pathways or extent of intrusion.
The profiling revealed that the kitchen, which has a ground-bearing floor, had over double the radon levels found in the living room which was above the lower ground floor.
Within the lower ground floor office, located directly beneath the ground floor living room, there was found to be a radon intrusion ‘hot spot’ indicating four times the level in the kitchen and nine times the level in the living room.
Due to the split-level construction, there was no communication between the lower ground floor sub floor and the ground floor kitchen sub floor. As a result, it was necessary to install two separate radon sumps to tackle the radon ingress in all parts of the property.
Using diamond core drilling, PropertECO technicians created mini-sumps beneath the building and installed exhaust pipework.
Radon sumps work by creating a point of low pressure beneath the building towards which, radon gas in the surrounding soil is drawn to and can then be safely vented away from the building using pipework and an inline fan.
PropertECO chooses to use RadonAway RP145i radon sump fans for such systems due to their excellent reliability backed by a manufacturer’s five-year warranty.
Results From Radon Mitigation Works
Post-mitigation testing was carried out over a period of three months using passive detectors. The results showed concentrations had been reduced significantly throughout the home – 36 Bq/m3 in the kitchen, 30 Bq/m3 in the living room, 29 Bq/m3 in a ground floor bedroom and 31 Bq/m3 in the office.
Maintenance Of A Radon Mitigation System
A year after moving into the property, our clients asked PropertECO to carry out repeat testing and a ‘clean and check’ maintenance inspection on the sumps.
Having successfully lowered the radon concentrations, they were aware that if the mitigation systems stopped functioning for any reason, radon levels would rise once again so this yearly service was a small price to pay for peace of mind.
PropertECO can test your home for radon and design a suitable radon mitigation system if high levels are found. Get in touch with our radon specialists by filling in the form down below.