Can a false chimney add to unwanted sound transmission

[roxy22]

I am considering having a false chimney built to allow me to have a balanced flue type of gas fire installed with the flue exiting outside at 7 - 8 feet height. This is necessary as the exit cannot be at floor level due to the passageway being too narrow and my current chimney does not comply with regulations.

I live in a ground floor conversion flat which has had a false ceiling installed about 10 years ago to cut down noise transmission from upstairs - the conversion included little if any soundproofing when it was done. It has been largely successful but there is sometimes some sound from the tv upstairs, depending (I think) on exactly how close the tv is to the wall - this I presume varies when cleaning/dusting leaves the tv in a different position. The sound is being transmitted via the wall and my fear is that a false chimney attached to that wall could act as an echo chamber and amplify any sound. This fear may be totally unfounded, but I would be interested in any thoughts on this.

The chimney will be plasterboard, installed by the gas fire company and the fire will be installed by a registered gas fitter.

Thanks in anticipation

 

[CBW]

A lot can depend on British standard, gas safe regulations and the manufacturers instructions. What type of flue is being installed and why do you think carpenters will know this answer?

 

[roxy22]

Very helpful, thanks.
It is difficult to know what thread is most appropriate for this question. I would ask where you think I should put it, but wouldn’t want to feed you such a predictable opportunity.I don’t think gas safe regulations are relevant, though of course, important.

 

[CBW]

Would have put this is plumbing and heating section tbh. What type of flue is being installed?

 

[roxy22]

I understand it to be a standard balanced flue as produced by Gasco for a Riva2. This may not help , but as a non technical person, it is all I can add.

My thinking, perhaps incorrect, was that any problem with noise transmission was more likely to be caused by the void created by the false chimney, rather than the flue itself.

 

[CBW]

If it’s a balanced flue, then no false chimney required. I can’t see noise transmission from a gas fire being an issue.

 

[roxy22]

A false chimney is needed to raise the outlet to a 7-8 feet height, as in my original post.
My concern is that noise might be transmitted via the wall from upstairs, amplified by the void and therefore be more of an issue for my flat. I wasn’t thinking of the gas fire producing troublesome noise.

 

[CBW]

Apologies, I should have read your post better I don’t think that’ll be much of an issue though either.

 

[roxy22]

Thank you

 

[Deleted member 174758]

If you are concerned about noise transmission, use sound bloc board for the cladding and make sure that where boards meet hard surfaces which can transmit sound that there is a minor (1 to 3mm) gap which is caulked with acoustic mastic. Similarly, framework abutting hard surfaces an be bedded onto acoustic mastic or foam to minimise any transmission of noise.