Blocking a chimney

[riph72]

Hello all,

I would like to block the bottom of my chimney for insulation reasons - would I have ventilation problems if I leave the top open, i.e. as is?

I've being looking at these:

http://www.chimney-balloon.co.uk/

Anyone have any experience of this type of thing?

Regards,
Richard.

 

[foxhole]

Yes , liable to have damp if it's not ventilated, just reduce the size of the chimney flue , don't block it.

 

[riph72]

Yes , liable to have damp if it's not ventilated, just reduce the size of the chimney flue , don't block it.

It's probably a daft question, but - why does it need to be open at both ends? I guess that this allows a *flow* of air, rather than just *access* to air?

Would this explain why partially blocking (i.e. reducing) with a product such as that I gave a link for earlier, is ok, as long as the blockage isn't total?

 

[Richard C]

why does it need to be open at both ends? I guess that this allows a *flow* of air, rather than just *access* to air?

You got it in one ; you also need a rain cap on the top to stop


the rain getting in!

 

[riph72]

Although it's highly unlikely I'll do this, what about removing the chimney altogether? How big a job is this, for someone who knows what they're doing? I see a number of houses like mine that are minus a chimney...

(Obviously I know I won't be able to have a gas fire anymore!)

 

[tim00]

Do you have an installed gas fire at the moment?

Removing the lot, and making good ( no decorating ) in structural terms it's not a "big job", but it's a dusty, messy business. Costs: what precisely is involved - rooms, openings, loft, cellar, stack? Research on this forum.

 

[Richard C]

Although it's highly unlikely I'll do this,

What’s highly unlikely? If your referring to rain entering an open pot, damp/rain permeating down the brick courses in the stack & lack of ventilation causing condensation then think again. You won’t notice it immediately & sometimes not for a few years but it will get you in the end, do some research; but hey it’s your property, do as you want!

what about removing the chimney altogether? How big a job is this, for someone who knows what they're doing? I see a number of houses like mine that are minus a chimney...(Obviously I know I won't be able to have a gas fire anymore!)

It’s still a bit of a job even if you know what you’re doing; it’s very messy, won’t be cheap & is notifyable building work. Not worth the hassle unless the stack is unsafe & why spoil the property for someone in the future who may relish the opportunity of an open or even a new gas fire!

 

[riph72]

Although it's highly unlikely I'll do this,

What’s highly unlikely? If your referring to rain entering an open pot, damp/rain permeating down the brick courses in the stack & lack of ventilation causing condensation then think again. You won’t notice it immediately & sometimes not for a few years but it will get you in the end, do some research; but hey it’s your property, do as you want!

what about removing the chimney altogether? How big a job is this, for someone who knows what they're doing? I see a number of houses like mine that are minus a chimney...(Obviously I know I won't be able to have a gas fire anymore!)

It’s still a bit of a job even if you know what you’re doing; it’s very messy, won’t be cheap & is notifyable building work. Not worth the hassle unless the stack is unsafe & why spoil the property for someone in the future who may relish the opportunity of an open or even a new gas fire!

I meant it's highly unlikely I'll remove the chimney, but despite the misunderstanding, your explantion was good info

Given the responses here (thanks, all), I'll forget the chimney removal idea - as I said, it was just a thought really, I was never likely to actually do it.