Radon and housing

Posted on September 12, 2020September 12, 2020

Can new properties be protected from radon?

Barriers (membranes) which are impermeable to radon can be laid across the footprint of a building during construction. It is important that these are installed by trained specialists, and not general groundworkers, as any gaps or splits in the material will allow the gas to pass through and can render the membrane useless. The current Building Regulations require newbuilds in certain parts of the country to incorporate radon protection. Approved Document C is currently being rewritten and the revised version is likely to require all newbuilds and extensions to include basic radon protection.

What should I do if I’m buying a property?

The Radon Council advises that all property purchases request a radon screening test to be carried out before exchanging contracts. It is often the case that a prospective purchaser will conduct a damp and timber survey before going ahead with a purchase, and it would be prudent to also conduct a radon test. If the test result is close to or exceeds the Action Level, it may be appropriate to negotiate with the vendor to pay all, or part, of the cost of remediation.

How much will it cost me?

As with most things in life, you get what you pay for. A test using a detector posted to you for placement under instructions should not exceed £50 per house. After the given test period, you post back the detector and the company concerned subsequently posts you full written details on a confidential basis.

If you have a level near or above the “Action Levels” quoted above, depending on the nature of the property, remedial action may have to be considered. The Council’s list sorts out the various kinds of service on offer. Remedial work charges will obviously vary according to the size and construction of the property.

Written schedules outlining the reasons and nature of work and including costs should be offered for all work quotations. In the past, some consumers have obtained details of the recommended remedial work from a reputable Company and have then used these details and had the work done by inexperienced operators. As a consequence several organisations now make a charge for such a schedule. You should check that this is refundable if the company is entrusted with the work.

Be advised that no one universal solution exists for radon treatment in existing buildings, therefore experienced contractors will be able to select a suitable method for your property. The Radon Council strongly recommends that radon detection and remedial work should be undertaken by persons trained and experienced in such work.

The Policy for Remedial Work Payment

The current situation in the UK is that legislation exists for “new build” housing in defined areas for domestic occupiers and for employees in the workplace anywhere in the UK. For the much larger stock of older homes however, no resources are available for remedial work.

There has been a considerable effort funded by the tax-payer to identify problem regions now designated as “Affected Areas”. The lack of financial resources when readings above the 200 Becquerel level (Action Level) are found in homes means that a large proportion of houses or flats needing remedial work are left in their original state, This is clearly unacceptable from the human health point of view and several proposals have been put forward to deal with the problem. Discretionary grants although available have seldom been awarded.

The Radon Council has proposed the one UK system that avoids unnecessary bureaucracy and initiates remedial work with the provision of the necessary funds when that is clearly required. The BRE and Council are in broad agreement that with current prices the average costs of remedial action for a domestic house will be up to £750 – £1,500. A few will cost more and some less. The proposal is that at the time of conveyancing (i.e. transferring ownership of a property), the results of a short term test (or preferably a longer term test if available) for radon be exchanged between the solicitors for the buyer and seller.

Should any remedial work be necessary then arrangements can be agreed for financing the work from the sale proceeds and for the mortgage loan being used for the purchase. The same kind of procedure would apply when tenancy documents are being prepared except that the onus would clearly be on the landlord to provide a property clean and fit for healthy occupation. These proposals would apply anywhere in the UK. They would also lead to an increasingly accurate picture of radon distribution throughout the country if the data could periodically be made available.

Other methods have been suggested or tried. For example, an indemnity insurance policy, or financial sum being retained as a kind of Bond. Such actions are not required if the results of a radon test are known. A Bond has the disadvantage of tying up sellers’ money together with associated costs.

What if I am not selling or buying a home? 

For your own peace of mind a test costing about £ 50 may well be a good investment. Keep a written record of the results against the day when you decide to sell. Only if your home requires remediation are you faced with a decision on taking action to reduce the level of radon gas. After consulting one of the remedial contractors on the above list, you may have a better idea of total costs and whether you can afford them.

Guide for employers

Posted on September 11, 2020

Under the Health and Safety at Work (Etc.) Act 1974, the employer bears the principal responsibility to ensure the health and safety of employees and others. Protection from exposure to radon at work is specified in the Ionising Radiations Regulations 1999

These regulations apply to work areas where the level of radon exceeds a defined threshold. One of the fundamental requirements is to reduce exposures to radiation to as low as is reasonably practicable.

Where radon levels are found in excess of 400 Bq m-3 in the workplace, then the first approach should be to apply remedial measures to the building(s) to reduce radon levels to as low as is reasonably achievable.

Measuring radon

Posted on September 11, 2020

How do I obtain radon measurements?

There are a number of reliable detection methods available for assessing the average radon levels within your home. Any of these can determine whether or not there may be a risk worthy of further study or remedial work (i.e. work to reduce radon gas levels).

From the scientific point of view, the longer the testing procedure the more accurate the results may be. The preferred method is to test over a period of typically 3 months, however methods of detection have been developed that give accurate readings of radon in a period as short as 7- 10 days usually essential in house conveyancing operations. They are a popular technique in both the USA and the UK.

Caution:- The Council is aware that some organisations are operating in the UK offering “Instant” radon sampling measurements using portable measuring equipment. Because radon levels can and do vary considerably throughout the day, any measurements of less than 4 days should be avoided.

As with any measurement technique it is the interpretation of results that are important. Such interpretation recognises difficulties in sampling, house construction, ventilation and human activities, as well as seasonal changes. Given proper interpretation the short-term tests are equally acceptable in deciding whether there may be a need for further detection or remedial work. A number of reliable and fully experienced companies offer a range of long term detection methods and several offer the 7-10 day tests as well.

What do I do if high levels are recorded?

If you find that you have levels above the current ” Action Level” (i.e. 200 Bq m-3 [Becquerels per cubic metre] for the home or 400 Bq m-3  in the workplace), you need to consider the wisdom of having remedial work carried out to reduce radon gas levels. The Becquerel referred to is the unit of measurement normally used by the industry. It is worth noting that the World Health Organisation have recommended recently that radon action levels be reduced to 100 Bq m-3. 

See  http://www.aarst.org/images/US_Highlights_WHO_Rn_Handbook.pdf

How can radon levels be reduced?

As the air pressure inside the building is the main factor affecting the entry of radon gas, techniques which alter this pressure differential are the most successful ways of remediating buildings with high radon levels.

Two such techniques are the use of specialist positive pressure units and retro-fitting a radon sump beneath the building.

It must be recognised that radon mitigation is a specialist and sophisticated service, where an understanding of the science of radon movement is required. Some techniques, such as the use of extract fans to increase ventilation can in fact exacerbate the problem and cause greater volumes of the gas to be drawn into the property. It would therefore be unwise to place such responsibility in the hands of an unskilled contractor.

Reducing radon levels in properties with basements is particularly difficult, due to the large area of low pressure created by the basement. A system should be used that will not only reduce radon levels in the basement but prevent the gas from being displaced into the ground-floor accommodation. Waterproofing to the British Standard BS 8102 must also be achieved if the basement is to be useable.

Given the nature of radon entry into buildings, radon should be viewed as something that needs to be managed, not simply to be ‘fixed’. Even with many years’ experience in dealing with radon mitigation, a specialist contractor may not always solve the problem at the first attempt. No two buildings are identical, as is the geology beneath any two plots of land.

It is therefore imperative that a radon test is done after remediation works have been carried out, to determine whether they have been effective. Where very high levels of radon have been found in a building, it may take several attempts and various combinations of techniques to sufficiently lower the concentration of the gas.