Flue Supports

[arran197]

Can someone clarify exactly what is needed on flues in lofts regarding support.

I know fan assisted boiler flues need to be supported every 1.8m as a minimum, in the appropriate places in order to support the weight of the flue. But what about open flue? I've just been & fitted a rigid bracket to a open flue (IL) coming off a precast flue in a loft. It had already got strap banding fitted. Is it that ANY flue now needs rigid clips/brackets where there are lengths through a space such as a loft? So effectively, any flue in a loft needs a rigid support or it is ar.

 

[GrahamM]

Ideally an open flue should be supported with rigid supports at every joint and ideally at both ends of a 45° bend.
If the cheapskate used galvy band as flue supports and it is in your opinion is securely supported I would NCS it.
If it has little or no support it is a clear AR.
What I have been taught and stuck to over the years!

 

[arran197]

To be honest, some of the service engineers working for the company go way over the top with flue clips. One put down for flue clips to be fitted to a section of flue that wasn't even long enough to get a clip on to! It's a strange subject really, because some people are under the opinion that after every joint there should be a clip, but what I have been lead to believe is that providing the flue is satisfactorily supported (ie. is resistant to external influences such as being knocked or a good gust of wind) then it is supported satisfactorily.

I've also been told that strap banding is not acceptable and needs to be changed to a rigid clip, but I wasn't sure if that applied just to fan flued appliances because of the added risk if the flue were to come apart.

 

[GrahamM]

Open flue and room sealed concentric flues are a different kettle of fish, but at the end of the day it comes down to your judgement and common sense.
The standard is every 1.8M as you mention, but again common sense should be used. A standard flue 2M long that has screwed joints and cemented through wall is going to be ok in most cases.

An open flue is a different story. They don't have the screwed joints and in general will have more complex, longer exposed runs with more joints and bends so need to be adequately supported.
Selkirk advise rigid clamps at min 2.5M runs and above and bellow bends for adequate support of their systems.

As in a lot of our rules/regs a common sense approach is required.