Removing a chimney, maintaining gas fire flue

[Slimmy]

Hi,
I've searched the forum for some answers but I can't find exactly what I'm looking for.

My parents' house has two chimneys, one of which has large cracks etc in it and my father would like to demolish it. We have worked out what is required in terms of safe access to that level (scaffold, roofing ladders etc), but have a couple of questions.

Firstly, the chimney currently has 1 gas fire at the base of it - clearly this needs a flue, but what exactly? How is this sealed into the roof?

Secondly, we need to 'fill the gap', so we presume that this is relatively simple in terms of matching the different layers - wooden supports, felt, battons, tiles etc... is there anything we should know?

I'm sure some of you must have done a similar thing - can anyone offer any advice please?

Many thanks for a highly useful forum.

 

[bobthebender]

I have put in many a gas fire for my local council using twin wall flue either inside or outside..It's not cheap though

http://www.selkirkchimney.co.uk/products/twin-wall-chimney.html

 

[JohnD]

Mine has what looks like an asbestos-cement pipe that comes out of the flue-blocks in the wall, inside the loft, follows the slope of the roof, and goes out through a sort of ridge tile. i imagine you have to know how to make it all gas-tight, though.

You don't need to demolish all the chimney inside the roof space, so you should be able to terminate into the stump.

 

[bobthebender]

Mine has what looks like an asbestos-cement pipe that comes out of the flue-blocks in the wall, inside the loft, follows the slope of the roof, and goes out through a sort of ridge tile. i imagine you have to know how to make it all gas-tight, though.

You don't need to demolish all the chimney inside the roof space, so you should be able to terminate into the stump.

Your type of flue are the ones we replace with the twinwall.
The joints crack and i was getting fed up of spending an hour in each roof space with fire cement fixing the joints.

 

[JohnD]

Your type of flue are the ones we replace with the twinwall.

and I was thinking of getting a new gas fire when funds permit. Hundreds of pounds, is it?

 

[Slimmy]

That is very helpful - thank you for the info.