Cutting Through Gable End for Chimney Pipe

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May 12, 2015
25
Halifax, NS
We are nearly done installing our wood stove. Our set up is in the basement, goes out the basement wall (which is above grade), and then up the side of the house. The only thing we have to figure out now is how to cut through the gable end of our house, but in such a way that isn't going to cause leaks.

Our gable is exactly 12" wide, and our Selkirk chimney pipe is 10" in diameter (6" pipe inside). We need to maintain a minimum 2" clearance to combustibles. I found this post on how someone "notched" out their overhang because they had the same issue I have. But does anyone have a suggestion on a tutorial on *how* to do something like this? We have no idea how to handle the shingles, membrane, fascia, etc and make sure it's all sealed up properly and prevent leaks. We're considering hiring a contractor for this if we need to, but we're trying to save the cash. From the ground up to the gable, it's about 15 feet.

This is our setup outside so far (obviously not finished or in use; we put the rain cap on to keep the rain out for now).
 

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We are nearly done installing our wood stove. Our set up is in the basement, goes out the basement wall (which is above grade), and then up the side of the house. The only thing we have to figure out now is how to cut through the gable end of our house, but in such a way that isn't going to cause leaks.

Our gable is exactly 12" wide, and our Selkirk chimney pipe is 10" in diameter (6" pipe inside). We need to maintain a minimum 2" clearance to combustibles. I found this post on how someone "notched" out their overhang because they had the same issue I have. But does anyone have a suggestion on a tutorial on *how* to do something like this? We have no idea how to handle the shingles, membrane, fascia, etc and make sure it's all sealed up properly and prevent leaks. We're considering hiring a contractor for this if we need to, but we're trying to save the cash. From the ground up to the gable, it's about 15 feet.

This is our setup outside so far (obviously not finished or in use; we put the rain cap on to keep the rain out for now).
Are you sure your 6" chimney is 10" exterior? It should be closer to 8" so your hole should be about 12. Which means you may be able to leave the face of the soffit
 
Are you sure your 6" chimney is 10" exterior? It should be closer to 8" so your hole should be about 12. Which means you may be able to leave the face of the soffit
FYI Some Selkirk stuff (their all-fuel “Sentinel” I think) has 2” insulation for outer diameter of just shy of 10.5”.

I just used it on a sauna install up north.
 
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FYI Some Selkirk stuff (their all-fuel “Sentinel” I think) has 2” insulation for outer diameter of just shy of 10.5”.

I just used it on a sauna install up north.
Thanks I didn't even notice he was canadian.
 
Canadian class A has 2" of insulation compared to US which has 1".
Some Canadian stuff does. I think they sell the supervent stuff in the big box stores with 1” up here too. The sentinel with 2” seems pretty skookum, was all they had at the middle-of-nowhere hardware store during our last install.

My ICC chimney is the standard excel with 1” of insulation. Tested and rated correctly. Something about 2 chimney fires and 2100*....

To the OP: if yours is sentinel I believe they offer the 45* class A sections for that type, if you wanted to avoid punching through your roof overhang. You wouldn’t be able to see up to the top from your tee though.

Good luck with the rest of the project, hope you get burning soon
 
To the OP: if yours is sentinel I believe they offer the 45* class A sections for that type, if you wanted to avoid punching through your roof overhang. You wouldn’t be able to see up to the top from your tee though.

Unfortunately, it's Selkirk Supervent, which does not allow offsets. We really researched on what to do regarding the overhang. ICC and even some other Selkirk lines make either offsets or an extending bracket to bypass a 12" overhang, but each chimney pipe was *very* expensive. Like, at least double or possibly triple the price. My local Kent (hardware store here in Eastern Canada) had a sale of Supervent for $93 for a 3' length, so I took a picture, went to Home Depot, and then got the price match and they beat it by 10%.

We considered making our own homemade bracket (my husband can weld), but everything I was reading about this said that here in Canada, homemade brackets will not pass WETT inspection. It needs to be the bracket supplied by the manufacturer for that specific chimney line (Supervent does not have an extended bracket for their line, nor allow offsets). So our choice was spend a fortune going around the gable, or buy the cheap chimney and cut through the gable. In our neighbourhood, we noticed only one house had the extension. Everyone else cuts through. My husband is also very uneasy having an offset, anyway. He is adamant that the best way is straight up (from what I understand, this is true).
 
Canadian class A has 2" of insulation compared to US which has 1".
Nope. The big box stores sell the 2'' insulated almost exclusively, while your local sweep or stove shop sells the 1'' - that was the case for the last 4 installs I was involved in. A three foot length of 2'' at HD/Lowes/HomeHardware runs about $100 and the 1'' is about $190 for a four foot length.
 
Unfortunately, it's Selkirk Supervent, which does not allow offsets. We really researched on what to do regarding the overhang. ICC and even some other Selkirk lines make either offsets or an extending bracket to bypass a 12" overhang, but each chimney pipe was *very* expensive. Like, at least double or possibly triple the price. My local Kent (hardware store here in Eastern Canada) had a sale of Supervent for $93 for a 3' length, so I took a picture, went to Home Depot, and then got the price match and they beat it by 10%.

We considered making our own homemade bracket (my husband can weld), but everything I was reading about this said that here in Canada, homemade brackets will not pass WETT inspection. It needs to be the bracket supplied by the manufacturer for that specific chimney line (Supervent does not have an extended bracket for their line, nor allow offsets). So our choice was spend a fortune going around the gable, or buy the cheap chimney and cut through the gable. In our neighbourhood, we noticed only one house had the extension. Everyone else cuts through. My husband is also very uneasy having an offset, anyway. He is adamant that the best way is straight up (from what I understand, this is true).
Too bad you didn't post this a week ago, I was in NS on vacation and could have stopped by for a consult. ;lol
 
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The 1" insulated pipe is for oil/gas fired appliances, 2" is for solid fuel and oil/gas.
I know ventis sells the same stuff there as they do here for solid fuel applications. They just need to test to Canadian standards
 
Most soffits for the gable ends of the house are none structural and one the outside of the building envelope )like the second pic) a decent handyman with some caulk, scrap wood, and tin can make that cut and have it buttoned up in less then half a day
 
Most soffits for the gable ends of the house are none structural and one the outside of the building envelope )like the second pic) a decent handyman with some caulk, scrap wood, and tin can make that cut and have it buttoned up in less then half a day
Yeah, ours is definitely non-structural. My husband is pretty handy, and has done a great job with our install so far. But he is just really unsure of how to handle cutting and the membranes, shingles, proper seals and stuff. I wish there were some step by step clear instructions online, or someone video recording themselves doing something like that.
 
Anyone have tips or instructions on how to cut through and seal up?
*bump*
There really are way to many variables in construction techniques to give you much help. When I do them I try my best to leave the face of the soffit in place. In your case it looks like it is aluminum faced so it is non combustible. If it was me I would pull off that face cut everything out of the way then put it back on. And put flashing on the roof which may need modified so it doesn't hang over the edge of the roof. The bottom can be trimmed with aluminum stock as well. If you don't have room to do that you will just have to cut it all out and rebuild any lost structure. Then make aluminum flashing to seal it all up
 
I think Selkirk makes an adapter to go from one type of pipe to another. I recently used the 6" duraplus triple wall pipe with a 15degree offset and I believe it has a 10" outside diameter. Maybe you could just use the more expensive duraplus for the necessary offset and a length of it one either side if necessary?
 
I think Selkirk makes an adapter to go from one type of pipe to another. I recently used the 6" duraplus triple wall pipe with a 15degree offset and I believe it has a 10" outside diameter. Maybe you could just use the more expensive duraplus for the necessary offset and a length of it one either side if necessary?
Duraplus is about the least expensive pipe on the market. And I much rather see the soffit notched than an offset. It looks better and works better
 
I agree that a straight pipe is always better than having an offset but it is an option.

Absolutely an offset is an option. I just use it as a last resort

No, and no. Some chimney lines, yes, you can use an offset for the chimney outside, but not with this SuperVent line. Twice, it says it in the instructions not to do this (see attachments).

We could have purchased a chimney line that allowed us to offset, but the problem is that these lines were double or triple the price. I got Supervent 3' lengths for $86.29. Buying a line that allowed the use of outdoor offsets would have cost us significantly more money.

But we got it all figured out anyway. Found a guy who cut a notch for us and sealed everything up for $150 (see picture).
 

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