Sealing An Unused Chimney Thimble

Apply a bead of butyl rubber caulk around three sides of the chimney at the top and set the cut piece of metal on the chimney so the edges line up with the caulk bead.

Sealing an unused chimney thimble.

There is one important detail for the top cap. Press the metal into the. Firstly remove all of the duct tape and put them in a disposable garbage bag. Leaving the duct tapes lying on the roof especially if it is windy will increase your cleanup job later.

Usually unused chimneys are capped off with a bent sheet metal covering and perhaps a wire strap or weight on the top. It s important that your chimney service technician checks that the area that gets closed off has a lining. You can do it yourself in a few hours for a few bucks. Watch this video and see how.

The proper way to close off a thimble port is with brick and mortar to create a solid and safe enclosure. 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. If there s no lining due to the flue then a new one needs to be installed. It must be a complete rain shelter not just the spark cap that is normally on a chimney but at the same time it must not be sealed air tight.