Every professional heating and plumbing installer knows how important it is to comply with regulations, but guidance notes and different regulations sometimes appear to conflict or can be open to interpretation. Russell Armstrong, MD of RA Tech UK, calls for greater clarity.
Russell Armstrong
Twitter has a habit of throwing up some interesting subjects and a while ago a quality technical discussion took place and went on for a few days! Many contributors put into question the subject of fit for purpose D2 pipework and what materials it should be made from and why some materials are currently not allowed.
Having studied this area for some time now, in quite minute detail, I would like to just say what the regulations require and then ask why have we come to this juncture?
The first thing to say is that I am talking exclusively about unvented hot water heaters D2, and not that of boiler discharges. (Boiler discharge D2 requirements will need specific regulations when the time comes).
Rules and regs
The water regulations are written in such a way to tell us what can and cannot be done in order to ensure public safety, avoid risk of contamination and minimise waste. Likewise, the G3 Building Regulations are set out to address many of the same issues, but when the two meet it throws up some interesting technical requirements!
In the G3 guidance pages, it tells us that ‘in the opinion of the secretary of state this can be achieved by….’ These notes then tell us one way in which the regs can be interpreted and that if we carry out our installation in that particular fashion we will be ok and would meet the G3 regulations.
However, what is not so obvious is that the guidance is NOT prescriptive. That means that we can do whatever we wish as professional engineers, provided that, in the parlance of the regulations, they are ‘no less effective’.
Encompassed in the introduction to the Approved document, it states (page 3, paragraph 3 line 6): ‘It is also important to note that there may be other ways of achieving compliance with the requirements. There is, therefore, no obligation to adopt any particular solution contained in this Approved Document if you would prefer to meet the relevant requirement in some other way’.
How effective?
So here we have the conundrum – if I do something that is not in the scope of the guidance, how do I prove that it is ‘no less effective’?
There are two aspects to that. One is if the subject is clear, such as ‘the widget pipe must be made out of copper to grade xyz when used in this application’. This leaves no scope for interpretation, it is clear cut, it either is or is not made to that specification.
But what if someone invents a new product made of different material? Can that be used? Well on the face of it, it would appear to be a resounding NO. But what happens if it is good enough to do the job, i.e. it is fit for purpose? Can we as an industry move with the times and allow a change of material rather than saying ‘No, the regs don’t allow it’?
Well, the answer lies in the interpretation of what is required and that is where, in my opinion, the regulations are open to interpretation. But they forget to tell us (sometimes) what issues a particular regulation is intended to address.
Lets put this to the test on our subject heading of D2 pipework. If the regulations simply stated that the pipework must be able to withstand so many litres of water passing at such a temperature within a certain a period of time without distorting, deforming or otherwise allowing water to escape (for example), then the waste pipe manufacturers would be able to make a pipe to cope with that. It therefore becomes a performance specification and a regulation to boot.
However, the guidance gets a bit fuzzy at times. On our subject, (G3) one of the early guidance notes makes it pretty clear and conclusive. Titled ‘discharge pipes from Safety devices D1’ G3.3.50 states: ‘Safety devices should be discharged either directly or by way of a manifold via a short length of metal pipe to a tundish’.
This statement appears to leave no scope for interpretation. It is clear-cut, it needs to be metal.
At G3.3.57 we come on to the subject of the D2 material. The installer seems to have a few choices of what he may use, such as:
a. metal
b. some other material that has been demonstrated to be capable of safely withstanding temperatures of the water discharged and is clearly and permanently marked to identify the product and the performance standard, eg as specified in the relevant part of BS 7921-1:2006 (NB this BS has now been superseded by a 2010 revision).
So the installer rushes off and finds he has to spend £170 on the relevant BS with BSI. But when we examine the performance standard we find that BS 7921 is more to do with heating pipework under pressure rather than waste pipework! How can this be?
How can the regulations point to a standard that doesn’t give the answer we need? Without providing the raison d’etre, we are left to try and understand how we can be ‘no less effective’. No less effective than what? And therein lies the arguments that rage across the industry time and time again.
So I say to the regulators, define your reasons and let those clever and resourceful plumbers come up with ‘no less effective solutions’ to them. If you keep with what you have, then I say the regulations themselves may not be fit for purpose to keep innovation flowing!
Plumber and inventor Russell Armstrong is the inventor of the hotun dry trap tundish. For more information, visit hotun.co.uk or follow on Twitter: @ratechhotun
