Decommissioning a combi boiler - removing the flue?

[borndigital]

Hello - I wish to remove an old and defunct gas boiler and wondered what is the best thing to do with the flue?

It's an approx 25 year old flat on 1st floor in a timber framed building. I think the building would have been built with some kind of gas boiler and flue but I guess this combi boiler is not original.

Should I ask the workman to remove the flue and make the walls good or is it better/possible to cap off the flue in some way? ie to save touching the external wall at all. If it can be capped off would it be sealed or need to be ventilated?

Thanks for any help!

 

[Rmm]

It may be the neatest solution if you are able to cut the flue internally flush with the wall and fit a plate over the hole. It would need to be fire resisting, probably 60 minutes, so something like Supalux or Gyproc Fireline board. Either way you'll need to let your landlord know what you're doing to avoid being in contravention of your lease.

 

[borndigital]

Thanks so much for your reply - apologies for the idiot question but why would it need to be fire resistant? No problem with using the fire resistant stuff but when seeking consent for the works it would be great if I can explain my thinking. I was also concerned about moisture/condensation and therefore ventilation on the plate - do you have any thoughts about that?

 

[Rmm]

By no means an idiot question. So given that you have timber framed construction the Building Regs compliance will have been dependent on providion of adequate fire resistance of the linings protecting the external timber frame from a fire within your property. Any penetrations through those fire protective linings similarly need to be designed in a way that neither compromises the fire protection, for example with an intumescent sleeve around the flue, and doesnt compromise the role of the vapour barrier, perhaps by sealing around the vapour barrier where the flue passes through, both good reasons to leave the flue in place. Comprising fire protection on flat blocks is a serious matter and so if in doubt you may wish to make an enquiry with your local Council's Building Control Department who will provide you with the best advice.

 

[borndigital]

Thanks for the detailed explanation - that's really helpful!