We have a steep roof and a stove that is going near the eve - so we want to the chimney to jog over as far as possible inside the attic before exiting.....
Problem is that the ceiling support box I saw says to go up 18” with a straight pipe min. That means the first 30 degree can only be installed way up there.
Anyone have any experience with this? Maybe one brand allows turning before another, or perhaps by making a custom or cutting down an attic insulation shield I could turn sooner.
Turning as low as possible is important because the chimney can only slope 30 degrees, which the roof slopes 45 (12/12), so unless I start low, the two will “meet” before I get too high up in the attic.
While we are at it, any math whiz want to tell me how much closer together two lines - one at 30 degrees and one at 45, get together for each foot of run? Example: The lines start with 3 feet in between them.....how far is the run til they meet?
Can you “jog” the chimney pipe over before it enters the attic? Sounds like no matter what you do, you wont have enough room inside the attic for the jog over. Unless of course you trim the attic shield down. How much would you have to trim off? How deep is the attic insulation?
I can jog a little inside, that will help somewhat with initial clearance from the joists to rafters.
There is a full 10” or more of insulation - but the 30 degree can be installed parallel with the ceiling joints, in other words I don’t have to clear the joists before turning. And insulation can be cleaned out of that area - even a home made insulation shield can be installed. It would be nice to install an 9” section and then the 30 degree.
This might be something I have to get a fax from the engineering dept for......
Whats the purpose of the jog? to clear the rafters? Or is this the chimney you were installing that is near the roof valley? Would 2- 45’s give you better clearance?
Hog, it is the valley install - and the reason is twofold or more - to get away from the valley, and also to get as much pipe in the attic (going up toward the peak) before I have to go up through the flashing because that means less pipe outside. As it is, I will have to resupport the pipe outside and probably have 8 feet about the flashing. If I went straight up, or a slight jog, I would need 12+ feet of chimney sticking up through the flashing.
Enclosed pic shows how straight up (1) would exit roof low, and pipe which jogged over inside the attic would exit closer to peak.
Man you picked a sheety place to run that LOL.
You def want it at the higher spot. The further away from the valley the better. Don’t want to create any kind of possible water damming near the valley. Not to mention, wanter coming off the high side of a valley during a hard rain runs sideways and is just another potential possible leak problem at the flashing.
I am having a tough time picturing 2-30’s in the set up, wouldn’t you get higher up through the roof with 2- 45’s and a longer run of straight pipe in the attic?
Any way you look at it, that going to be a motha to get to top and clean.
Craig, if you measure horizontaly over 3’ where the rafter intersects the top of the outside wall, it will be 3’ staight up to the roof, given your 12/12 pitch. If you install your pipe at 3’ horizontal from the wall location and have a 30* elbow at attic floor (or top of the ceiling joist) level and proceed upwards with pipe at that 30*, you are moving horizontaly at 2/3 the rate of the rafter. Therefore you will hit the rafter after gaining 2” horizontaly for a total of 5” from the outside wall. The total height (not length) of the pipe in the attic will be 5’. Measuring 45* up the slope of the roof from where the roof is over the outside wall should be about 7” up where the chimney will come through.
Welp, Begreen, your right again.
Just found this on Duravent’s site. Apparently in the U.S. NO all fuel chimney is allowed to use 45 degree elbows per code.
Yeah, 30 is always max with masonry or metal chimneys. It is really just about the only place in this entire house to put a chimney. I will be able to clean from the bottom, I think.
I will check the old fashioned way - use a 2x4 in the attic which I can hold at a 30 degree angle and see where that gets me.
Grizz, that sounds about right. I am starting about exactly 3 feet in!
Craig, why not buy a couple 6” adjustable galvanized elbows (set a 30 degrees each) at Home Depot and a straight 5’ section also, relatively cheap, and use them as a template for what you are trying to achieve?
I did this for a template for the layout of my insert liner and it worked well.
Can you put it where the sewer vent is,That way you can all most go straight up with your stove pipe.And your away from your valley. It not that hard to move sewer vent. This also puts you away from the second floor on the right. Hope this will work for you
4 elbows allowed, none more than 30* from vertical
so maybe
30* from stove to ceiling & 30* to pipe #1
30* from pipe #1 above ceiling to 30* & pipe #2 & into roof exit
