View Full Version : What is this for

Jeff Eastman
05-09-2007, 05:07 PM

David Banks
05-09-2007, 05:24 PM
Opens the damper usually at the top of the chimney.

James Duffin
05-09-2007, 05:42 PM
Do you have a picture of the flashing on the side of the chimney? This view looks like the flashing is ok?

Jerry Peck
05-09-2007, 05:56 PM
Opens the damper usually at the top of the chimney.

I think I remember Bob H. saying those were not allowed ... ???

David Banks
05-10-2007, 03:44 AM
Jeff. They may have removed the top damper but not the chain for some reason.
Jerry. I remember Bob mentioning those a while back. I think he said they were preferred? Hopefully he will chime in.

Bob Harper
05-10-2007, 06:37 AM
Naw, I sell and install top dampers all the time (yesterday in fact). However, one brand, Lyemance is notorious for two inherent problems: downsizing (= smoking) and squirrel traps. Due to the design, the weight of a squirrel will open the valve plate dropping Rocky down into the Fp. When he tries to climb out, his weight on the cable pulls the valve plate shut. Should have been in a horror movie--"Put the lotion in the basket...." The Lyemance can be identified by the black aluminum wedge shaped casting when closed which becomes a figure X when opened and the lack of a rain cap/ spark arrestor/ animal or leaf guard. Newer damper/ cap combos are available in stainless and work well. BTW, during a chimney fire, a Lyemance damper will melt. This is noted as a blob of melted aluminum lying tangled on the smoke shelf with the cable attached.

That round tag on the spring handle is a cheat sheet describing how to operate it. Pull down and hook it under the bracket to close the damper. To open, move the chain to the open and it springs up about 5-6" Boing!

Nice flashing job.... The caulk and nails are especially touching. The mortar is erroded and will need to be repointed before long. Err, yeah, that cricket could have been extended a little better but you know a little trimming of shingles with a knife would go a long way to improving water flow. I'd be a lot more concerned with that galvanized metal exposed. G-90 26 gauge galvanized sheet metal will eventually fail. When exposed outdoors, it should be painted at the very least. I would recommend they replace this cricket eventually with a proper copper one and properly step flashed without nails or caulk.

Bob Harper
05-10-2007, 06:37 PM
Ha! Ha! I Can see that cricket with my super internet vision!

Ok, just guessing but it sure looks like plain galvanized and the most common is G-90 such as used by HVAC ducts and 26 gauge is also one of the most common thicknesses. Same as most smoke pipe.

Regardless, if it is indeed galvanized, it should be painted. The acid rain reacts with the zinc so it really isn't so rust proof. You could use stainless steel such as 304 but it is more expensive than galv. though currently less than copper, but does not solder the way copper seams to. Copper is a great material for crickets because of the workability, ease of making standing seams, soldering joints, makes the customer feel like Jedd Clampett, and weathers nicely. Aluminum would work but doesn't solder and isn't as durable.

There may never have been a damper installed. Even if there originally was a throat damper, they cause problems, which the top damper corrects. Throat dampers are notorious air leakers. This reason alone sells tons of top dampers annually. People are tired of losing heat up the stack, funky odors coming down the chimney, oil fumes or the upstairs Fp smoke coming down into the basement Fp, etc. etc. Don't get me wrong, the Lyemance has been around for over 25 yrs and done well. I just personally like other types.

You are correct to be suspicious why something is out of the norm but these dampers are the proverbial better mousetrap so don't think there has to be a defect because one is installed. Think of them as upgrades if nothing else.

So, was that cricket galvanized steel ?? ;-)