Bombproof Chimney Cap
Lead flashing keeps water out and protects masonry.
After a long winter, I often see the tops of chimneys disintegrating, sometimes to the point where entire courses of brick or stone have been loosened by daily freeze-thaw cycles. Eventually, I’ll see towers of staging set up at some of these houses as masons replace half the chimney.
A good chimney cap keeps out the water that causes this damage, thus preserving the chimney top. A piece of bluestone standing on masonry legs is a common way to shield the delicate crown, but an alternative that I use is to cap the crown with sheet lead. Lead doesn’t deteriorate meaningfully, so a chimney crown capped this way should have no end to its service life.
Contractor-oriented lumberyards stock sheet lead, and it can be found online. Lead is sold by the pound in rolls of various widths. (I use 2-1⁄2-lb.-per-sq.-ft. material, which is 0.042 in. thick.) Even…