Closing a chimney pot with a pyrex lid and no nails

[Peterpiper]

I'm thinking of closing an unused chimney pot with a pyrex lid sealed with no nails and covering any holes. The idea is I'll be looking to do a loft conversion in around 5 years so until then a cheap and cheerful solution. Insane or genius?

Cowels cost around 40 quid and I don't fancy cutting breeze blocks to size at such a height as I don't know the dimensions of the pot from the ground.

 

[Mr Chibs]

I thought it needs to be ventilated?

Vent in the room and elephants foot or cowl on the stack??

 

[Peterpiper]

The open chimney let's a lot of heat out during the winter and also I fear because the chimneys have been removed is causing a musty smell with the water egress onto the loft insulation

 

[Peterpiper]

I thought it needs to be ventilated?

Vent in the room and elephants foot or cowl on the stack??

When a chimney stack is removed the chimney pots no longer ventilate the roof so it's the same difference no?

 

[denso13]

You need to ventilate the chimney itself.