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Chimney stack removal  



Hi Just started to take down my chimney stack and was surprised to find no cast iron pipe.

i have attached 2 photos of what i found,any body else came across this looks like a concrete fire box at the bottom and the stack feels like tin.

any help much appreciated

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Hi Steph, can you send me your postcode to [email protected] so I can visually check your houses consruction type from Google Streetview please?

Alternatively, go to your profile from the menu bar above and you can send me a direct message from the message tab below your profile picture.




4 Answers

Great, shouldn't pose too much of a problem and with the flue being lightweight, you may be able to leave the last section exiting the roof in-situ after capping off. It would at least save having to patch over the exit hole.

Hope it goes well.


Thanks for providing the postcode Steph,

I must admit that when I first saw the exposed flue, I actually considered that the property might not actually be a BISF (British Iron & Steel Federation) built house, due to the strange configuration of flue pipe that you have there.

However Streetview has confirmed that your house is of BISF construction so I can only presume one of the following;

A) The original cast iron flue and fireplace if originally fitted, may have been replaced some time in the not too distant past, for reasons as yet unknown.

B) There is a small chance that this may have been fitted at the time of construction as many builders substituted a variety of materials due to shortages of original materials, however I feel that this is unlikely. In part because I have never personally observed this type of flue in a BISF house before nor have I ever found reference to any other flue configuration or substitute for the original cast iron flue. 

I can just about see four metal prongs protruding from the ceiling, around the top of the flue pipe. This looks similar to what would have been the original flue cage but I can't quite tell if it has been cut or manufactured in this way.

Could you take a few more photos of that section please and if possible include a close up shot of the end of the steel?

I've taken a look at the interior of similar properties nearby and even in those, the fireplaces do appear to vary but from a safety perspective, can you confirm that there is no continuation of the blockwork/ fireplace in the bedroom directly above? I doubt there is but just want to be sure.


Steph, on closer examination of your image, I can clearly see where the original timber stud that would have surrounded the floor through to loft steel cage. 

I can also see a portion of the original plasterboard that would have encased the flue, so I think it's pretty safe to assume that this is a later addition.

If you intend to completely remove the fireplace, you will need to trim away those projecting support struts with an angle grinder, but I advise extreme caution as the sparks can easily ignite any combustible material nearby. It's best to spray dampen\ cover everything combustible nearby and even then, you mat still find that some of the steel may still protrude below the ceiling.

There are some workarounds but I can advise you better when where have an image looking up toward the cage, with the lower flue and brickwork removed.

flue bisf


Yes that's what i thought.there is nothing up stairs just plaster board .

it dose look like its been fitted later i do know these houses had a make over in the late 70s,it carries all the way up to and through the loft.the flu feels like tin with a filling of insulation bits inside looks like rock wool.

i will take pics as i go on and let you know





I Have made a small hole in the casing and found out that there seems to be the cast flu still in the middle surrounded by insulation pics attached.

it makes me wonder how it is supported other then the cast concrete fire pit at the bottom  because all the frame that used to support it has been cut out to put the insulation on back in 1980 when they had a face lift.

I don't want to remove all of the flu just the downstairs but that's looking more difficult now.I will add a few pic now and another one in the loft later

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I Have now abandoned the project as it would be to much to take down all the flu .so boarded it all back up again.


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