Should i pack the pre-cast flue

[888]

I've just removed a fake chimney breast in my new-ish build house. The pre-cast flue still exists but i now have a flat wall which i am about to plaster over.

Before i do this and cover up the hole should i pack the base of the pre-cast flue?

There will be a v.small hole in the plasterboard which allows the gas pipe to pass through so i can connect it up to a gas stove. So air flow is possible through this tiny gap.

So i am in 2 minds whether i need to pack the base of the flue with fiberglass. Someone suggested wire wool but the gas man we are having said this isn't a great idea and fiberglass would be best.

Should i leave it or would it be best to pack it?

The new gas stove is going to sit on the new flat wall with an active up and out pipe which will be drilled straight through the flue so it will be unusable anyway. I just dont know whats best if water etc gets into the flue.

 

[simond]

Old flues can suffer from internal condensation, this is avoided by fitting an internal air brick/ventilator.

If you intend to permanently seal it, what you put in the end is of no consequence, you still run the risk of internal damp.

 

[ChrisR]

A small "hit and miss" vent is the usual.
Wire wool would be a rusty mess in no time!

 

[Agile]

I assume you are capping off the top of the flue???

In that case you need a proper ventilation of about 90cm². This could be in the loft or in the room.

If there is a gas pipe within the void then you should have ventilation at or near the top of the void as well as near the bottom of the void.

Tony

 

[888]

THere will be an extraction pipe for the new balanced flue drilled though in the void of the pre-cast flue.

The concrete block flue turns into a pipe in the loft before going up to the roof.

No1 has actually mentioned we should do anything at all to do with capping off or plugging the base. I just thought i'd ask the question though incase its a major issue if i dont do anything.