While you do want the top capped you should not seal it off completely.
How to seal an unused chimney top.
Seal unused chimney top and bottom about the author renee miller began writing professionally in 2008 contributing to websites and the community press newspaper.
How to temporarily block a chimney.
When retiring a chimney many chimney experts recommend using roxul a hydrophobic mineral wool insulation which means that it will dry out if it ever gets wet.
Sealing and insulating the clay flue at the top and bottom of the stack will ensure the job will yield these desired results.
Does an unused chimney need ventilation.
Even if you are not comfortable with climbing up to the roof and doing it.
This way if the fireplace is ever to be used in the future the piece of stone can be removed easily without causing any damage to the flue.
How to permanently block a chimney.
Plug and seal air tight the horizontal line at the level of the vapour barrier in the house and cap the top.
If your damper is near the firebox you can use insulation to seal the chimney.
Closing down an unused chimney.
Sealing your older unused chimney should not be a complicated task as long as attention is paid to prevention of air intrusion as well as environmental and pest control.
Capping the flue is one of the best ways to close up the top of the chimney as it will still allow air to get in and out preventing condensation from building up.
The long term savings associated with sealing the chimney has already been mentioned.
Gradually move to the top of the chimney.
If you want an easy way to temporarily block and unused fireplace flue to stop a draft you should consider installing a top sealing damper.
The top 5 chimney killers.
Wait for at least 10 to 15 minutes before applying the second coat and once again begin from the bottom.
Installing the chimney cap.