Gas fire , chimney liner query. Minimum 125mm/5” ?

[Riley]

It’s kind of all of the above mate. I’d be very sceptical of a bespoke fire full stop

 

[Toby emery]

This is why I wouldn’t get my fires as I wouldn’t want to put my name to one! Thanks for the advice anyway. That’s the one dimension they did give, the builders opening. And it’s 1m straight from the gather plate to the first bend which it was.

 

[Riley]

I’d steer clear unless you’re going to push your mate to find out more info

 

[firemant]

A BASKET fire requires 100cm of ventilation and a min 175mm flue.

 

[firemant]

Brand new chimney? Don't necessarily even need a liner. Manufacturer will say if it needs air vent...if it's s DfE then could potentially need air even if it's only 6kw.

If I have understood correctly, he is not buiding a chimney. He is using rigid twin wall flue.

350mm is way too big, it almost certainly should be 175mm, plus the the second skin, so around 225mm in total.

 

[firemant]

View attachment 37204 I personally would be happy using a 5” pipe as from what I’ve read. But I can’t do the work.

You would be wrong.

Is the chimney breast built in block/bricks, or timber?

Tell the owner to contact gas safe. The fires must be notified, and the flue comes under gas work. Use the GS find an installer to check his registration or ask GS.

A registered fire guys should not be asking "lots of people". Flue if that type and size is horrendously expensive (and it will be insulated) - it probably would have been cheaper to build a proper chimney. Assuming, of course, that it has been procured legitimately.

- Direct Flues

Furthermore, only a nutter these days would fit a basket fire. As has been pointed out, they are pretty much decorative only. With a correct ventilator, they can actually have a NEGATIVE efficiency. The 6Kw is never going to heat a decent sized room, so central heating will be on. The fire heats up the chimney, massively increasing the air changes in the room, which will suck out the warm air heated by the rads.

This will not end well.

 

[Andy Diffley]

Depends on the size of the builders opening, if it’s not a standard size the flue size may need to increase.