If your chimney is covered with stucco (parging) like mine, perhaps you could cover the flashing with it as well, at least at the top? Maybe flare it out a little so the rain drops fall just outside the flashing?

Lead flashing would be quieter, I think, but can you still buy it in this over-controlled safety-paranoid dictatorship--some stupid kid might climb onto your roof and eat it! :)

Negative on the stucco. We're in CT, not too much stucco around here. There's some, but not much.

-Gil

Gosh, you CAN still buy lead flashing--24' roll for $123 at Lowes!

Not only will lead flashing be quieter, but it will be more leak proof. Aluminum expands and contracts so much with temperature changes, it's just a matter of time before leaks develop around the chimney.

I take it this is something a very handy experienced home owner can undertake?

A "very handy experienced home owner" can undertake replacing the aluminum flashing, but I'd see what a mason or roofer would charge first. Flashing a brick chimney is a real skill developed over time. Doing it right means cutting into the mortar joints with a diamond saw to create a seat for the lead flashing in step fashion to accomodate the roof slope, then shaping the flashing carefully to drain water away, perhaps adding counter flashing, replacing the roofing material, etc. There's a good deal to it and chimneys vary a good deal. As with any project, you need to assess your skill level for the task. May turn out to be not terribly expensive to have a pro do it.

Aluminum flashing is a disaster in slow motion with masonry.
If it is installed correctly (counter flashed in slots in the mortar joints) the alkalinity of the mortar will eat through the aluminum in short order.

Copper or lead are what you want in mortar joints.

Make sure the fix fits the problem. You don't need to reflash your chimney (at least not yet); you need to stop the noise. Think "appropriate technology."

To just stop the noise, you need to do one of (a) redirect the water doing something similar to what CG suggested, with a little mortar, or (b) give the water drops a softer landing (a collar on top of the flashing made of anything quieter, maybe even wood), or (c) give it a chain or rope to run down so it doesn't do a free fall.

Much depends on how hard or easy it is for you to get to either the top or the base of the chimney. Most of our similar problems are at ground level so I just go out in my pyjamas at 4 am in the pouring rain and tweak the angle of the downpipes. Piece of cake :-)

Karin L

karinl, I thought I was the only one with the someone's-pounding-a-sledgehammer-in-the-downspout-next-to-my-bedroom problem! Unfortunately my downspout is un-tweakable, and disappears into some sort of drywell to boot.

Oddly, I only hear it after the rain's stopped, not in the downpour. The first few times, I thought someone up the street was beginning a construction project unusually early in the morning.

Then there's the deluded woodpecker who's trying to destroy the metal gutter at the other end of the house....

Just drink more before you go to bed :-)