Ventilaton of unused chimney breast

[Bex]

Hi - I have a roofer coming to cap and seal an unused chimney breast on my 1900 property.

The chimney will also be re-pointed and flashing secured. My question relates to the distal end which is currently blocked off  and plastered.

An air brick will be fitted externally but does there need to be distal ventilation at the lower aspect of chimney too?

 

Many thanks

[Carrerahill]

You should vent it, particularly in your case to keep the structure flowing with some air driving off moisture coming from the exposed wall.

 

As it is boarded/bricked up, I would probably just core it and fit a nice vent grille. Far less effort than trying to fit a brick. I'd also maybe initially opt for a smaller vent, like a 75mm core, you just want some air movement but don't want a huge open escape route for all your warm air. 

 

I personally have not ventilated one of our sealed chimneys but it is, internal to the house until roof level and is directly adjacent to 2 active chimneys. It is fitted with a vent cap. My feeling is that the warmth in the chimney structure will help keep the capped one dry. Think washed out milk carton sitting in the sun it does dry out. 

Edited November 9, 2021 by Carrerahill

[Marvin]

is the gable end of the building the footpath boundary?

[tonyshouse]

Take it down!

[Bex]

  On 09/11/2021 at 17:43, Marvin said:

is the gable end of the building the footpath boundary?

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There is a footpath alongside it, yes. Why?

[Bex]

  On 09/11/2021 at 19:08, tonyshouse said:

Take it down!

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Yeh the roofer mentioned this as an option 

[Marvin]

  On 09/11/2021 at 19:43, Bex said:

There is a footpath alongside it, yes. Why?

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Can't then vent through side of wall.

[Bex]

  On 09/11/2021 at 20:15, Marvin said:

Can't then vent through side of wall.

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thanks, yes, good reminder