I recently had a power vent water heater installed and now the chimney is no longer being used. It’s brick, on the outside of my 1.5 story house. It has clay flue tiles, an old steel liner and a smaller corugated metal liner all packed inside there. I have bricked up the opening for the water heater flue. There is a cleanout door at the bottom that opens up to the basement. My question is, what is the best way to seal it up to avoid water, condensation, etc. Vent it at the top and/or bottom or just seal it up airtight. I live in northern Illinois, where we get the extremes of hot, cold and humidity. I would prefer to seal it as much as possible so I don’t end up with a bee’s nest or something in there. We are planning to stay in this house til they wheel us out and I never plan on using this chimney again, so I am not opposed to permanently disabling it. Thanks
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It should be sealed from the top, and then blocked at the bottom (eg, stuffed with fiberglass for several feet) to prevent drafts up into it. Ideal, if you don't want to take it down, would be to install an new concrete or stone cap that totally covers the top, with no seams, to keep moisture out of it.
Another option to consider is taking it down to below roof level and patching the roof.
Unused chimney
Rick,
Put a 3/4-inch-thick piece of XPS foam on top of the chimney, a little bit larger than the flue, to seal air leaks. Attach it to the chimney cap with silicone caulk. Go down to your nearest stream or river, and find a nice flat stone, a little bit bigger than the XPS foam. Put the stone on top of the XPS. You're done.
You related to Junkhound??