MountainStoveGuy said:
some how, some way, you need access to the top. The cap needs to be cleaned. In the relativly short box like a insert has, it would be near impossible to get a brush up the chimney with the standard 4' rod. If the chimney is unaccesable its time to call in the pro sweep.
We did call the "Pro-sweep", two times so far. - he took one look at our chimney, muttered something untranslatable under his breath (I think it was Czech or equivalent) and cleaned it from the bottom.... He used what I think is one of those $500 "Viper" coil rod setups - one reason I've been talking about trying to do a poor mans alternative with a plumbing snake...
He did go to the top once, to put on a new cap that may not be a 100% kosher setup from what I've read here (explained below), though it was a commercial product that claimed on the box to be designed for our style of chimney. It took him three ladders to get there, and took longer to setup than the cap installation took. I'm not particularly uncomfortable with heights, but the setup made me nervous though I didn't see a realistic way to do it better.
Elk has seen our chimney, and I think he would agree that it's a real bear to get at. The main roof of the house is a 12/12 pitch (or 45注), the brick double flue chimney is built just inside the wall (nothing shows on the side of the house) and comes out about a foot from the edge of the house in the approximate middle of the roof run. On the upper side of the roof, the chimney is about 7' tall. (about 28 rows of bricks). It is about 22'-25' from the ground to the edge of the roof at the point where the chimney is at. There is a laundry room that comes out of the house (another 12/12 pitch roof)at a 90注 angle to the house with it's lower edge about even with the lower edge of the house roof. The sweep and I used one ladder to go from the ground to the laundry room, then laid a second ladder with a roof hook onto the house roof on the inside of the chimney, then jammed a short stepladder in between the roof and the upper side of the chimney. This let him get up far enough to put the cap on and screw it down on three sides
Thus far we've been burning all season on the new cap, and I see no sign of significant creosote buildup, (and given our stove that is saying something...) The cap is a single stainless 'roof' with a stainless mesh screen on it, that looks like approx 1/2" expanded material.
The possible problem is that it is a double flue chimney, w/ two 8/8 flue tiles, at least one of which is lined w/ a 6" SS liner. Both flues are at the same level, and the cap is covering both flues. The original setup had two mismatched caps which were at slightly different levels, such that it looked like rain on one of them would be funnelled down the flue of the other. The new cap solves that problem, but I think I've seen something that says if two flues share the same chimney, they are supposed to be different heights? - I don't quite understand this as it would seem to me like if they were different heights, the lower flue would inherently be violating the 2-3-10 rule on clearances...
At any rate, so far we haven't had any problems, so I'm not planning to mess with the setup unless we see a definite reason that OUR specific chimney needs something different to be done.
Gooserider