In recent posts, I've been talking about drafts and how they can be a big drain on utility bills, even for those like me that use electric heaters to cut down on their energy costs. In particular, I mentioned that sealing chimneys could be an integral part of this strategy, as they can often hide potentially pocket-draining drafts.
I received a reader question that specifically wanted to know about sealing drafts around a metal chimney, and this got me thinking about possible solutions, as I've never tackled the problem directly myself. What I do know is how to spot signs of a draft in and around these areas. For example, our reader was alerted to the problem after he found that the insulation in his attic was dirty in one area.
This led him to notice that the hole that had been made for the chimney was too wide, exposing the house to the harsh winter air. Popular Mechanics suggests using spray foam for sealing drafts around this area, however, you may not want to use the same stuff you'd purchase for a regular job. This means you might have to make a drive to the store and purchase special foams.
However, the experts sat you may want to check your renter's agreement before doing this if you live in an apartment or in an area where there's a homeowners' association. If there are rules against this kind of easy fix, your best bet may be to block the draft with aluminum flashing. After the metal is in place, experts suggest that those who are experiencing a chimney draft seal any remaining gap with high-temperature silicone caulk.
By taking these precautions, electric and oil-based heaters will fare better against the elements, and homeowners may be able to lower the high costs they experienced. But, you never really know if you've sealed all the drafts.