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Is RD = BBA?


Could be a tricky bit of maths but what I am really trying to answer is: ‘do you get as much from a Robust Details Ltd (RDL) listing as you do from an Agrément Certificate?’

The answer is ‘no’. The Part E Robust Details (RD) scheme was developed in order to provide housebuilders with a means of meeting Requirement E1 in the Building Regulations (England and Wales), covering resistance to the passage of sound between adjacent new build dwellings, without the need for Pre-Completion Testing – acoustic testing just before handover to the purchaser, with potentially costly implications if there was a fail.

The system has worked well and many providers of acoustic insulation systems have obtained RD listings. It is important to point out though that for most specifiers, purchasers and building owners acoustic insulation products will have other aspects of performance that need to be demonstrated, as well as an assurance that the specification of the product that passed the RD testing will not be changed to incorporate, for example, a cheaper component.

The BBA has worked with RDL to develop its RD Data Verification Scheme, linked to benchmark testing of specific components that may be used as part of an RD separating element. This process involves the BBA checking that the test data obtained by the manufacturer agrees with the requirements set out in the RD Handbook.

However, this is not the same as an Agrément Certificate.

When the BBA looks at acoustic insulation products leading to the award of Agrément Certificates, we take several key things into consideration that are not specifically accounted for by the RD scheme.

Under the Building Regulations, RDL’s role is specifically:

To approve new Robust Details as a method of satisfying Building Regulations (Requirement E1)
To manage the use of Robust Details in the house-building industry by enabling builders or their representatives to use them in new, attached homes
To monitor the performance of Robust Details and withdraw any that consistently fail to meet the required standards
To promote the use of Robust Details and publish information to help the industry improve the sound insulation performance of separating walls and floors in new homes
RDL is the only authority able to undertake this role.
The Agrément Certificate assessment involves consideration of all relevant regulations and standards that apply to the product in question, on the other hand including consideration of standards applicable in Scotland and Northern Ireland as well as England and Wales.

We look at the relationship of the acoustic insulation with other materials with which it is likely to be in contact including, for example, underfloor services, and how it should be fixed and how it will perform under long and short-term loading.

This latter aspect is important in helping us to arrive at a durability statement for the system, not something that you will find in the RD scheme. We also look to see that there is a system of factory production control in operation to ensure continuing production of the correct material. Some manufacturers claim that there are low quality foams being offered as part of floating floor systems and this is something that can happen if there is no third party control at the production source. Similarly, in acoustic battens, the quality of the timber is important and without control the temptation will often be there to substitute cheaper timber for the high-quality material that passed the original test.

Every BBA Certificate holder is liable to surveillance normally twice a year to ensure that the approved specification is still being manufactured and it is a condition of BBA approval that control processes are in place to ensure this is the case, even when our inspector is not on the premises.

There is an old rule when buying – caveat emptor or buyer beware, and it is as true in the acoustic insulation sector as anywhere else.

We say proudly that BBA approved products won’t let you down – who else can insert their initials in place of ours and make the same claim?

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