Furnace vent / roof requirements (want to eliminate chimney)
#1
10-29-15, 06:28 AM
Furnace vent / roof requirements (want to eliminate chimney)
Due to endless water leaks I'm thinking of eliminating my chimney above the roof line. It only serves as the vent for my gas furnace and water heater. (Combined)
Can we take it off just below the roof and extend the vent up thru the roof with proper boot/flashing etc?
If so, what are the height requirements? I have a 6/12 roof pitch. Currently the top of the cap extends past the peak of the roof. But I'm also afraid having that tall of a vent by itself will look pretty bad/ugly.
Can we take it off just below the roof and extend the vent up thru the roof with proper boot/flashing etc?
If so, what are the height requirements? I have a 6/12 roof pitch. Currently the top of the cap extends past the peak of the roof. But I'm also afraid having that tall of a vent by itself will look pretty bad/ugly.
#3
10-29-15, 11:39 AM
It leaked before I had the roof replaced last year. Had the roofers back out 4-5 times and never got it 100% sealed.
Now I can't get them to answer my calls.
I hired a different roofer to come out just a few weeks ago. They tore off all the old flashing, re-ice guarded around it, reflashed, and reshingled the whole thing. Still leaks. They've been out 4-5 times now too and can't get it to stop leaking.
Morter and brick all seems in pretty good shape. I'm beginning to have a hard time trusting anything done to it. That's why I was leaning towards just making it go away.
I'll grab a photo tonight. I'm just afraid no chimney with a pipe will look goofy.
Now I can't get them to answer my calls.
I hired a different roofer to come out just a few weeks ago. They tore off all the old flashing, re-ice guarded around it, reflashed, and reshingled the whole thing. Still leaks. They've been out 4-5 times now too and can't get it to stop leaking.
Morter and brick all seems in pretty good shape. I'm beginning to have a hard time trusting anything done to it. That's why I was leaning towards just making it go away.
I'll grab a photo tonight. I'm just afraid no chimney with a pipe will look goofy.
#4
10-29-15, 12:25 PM
Banned. Rule And/Or Policy Violation
>
This wont work. The transition would act like a cap on the chimney, impairing the ability of the appliances to vent.
What you can do would be to use a chimney liner the entire length of the chimney, terminating the chimney liner with some rigid vent that will extend a necessary distance above the top of the roof.
You would then connect the furnace and water heater to the chimney liner with some "B" vent.
Venting of gas appliances is a critical safety matter. If you want to do this, I'd pay a contractor to do the job right rather than mess around with it as a DIY job when you don;t know what to do or how to do it properly.
Of course, if you do that, you will have a roof jack going through the roof ---- how likely is THAT to leak?
This wont work. The transition would act like a cap on the chimney, impairing the ability of the appliances to vent.
What you can do would be to use a chimney liner the entire length of the chimney, terminating the chimney liner with some rigid vent that will extend a necessary distance above the top of the roof.
You would then connect the furnace and water heater to the chimney liner with some "B" vent.
Venting of gas appliances is a critical safety matter. If you want to do this, I'd pay a contractor to do the job right rather than mess around with it as a DIY job when you don;t know what to do or how to do it properly.
Of course, if you do that, you will have a roof jack going through the roof ---- how likely is THAT to leak?
#5
10-31-15, 05:43 AM
Sorry, finally remembered to take a pic before it got dark..
SeattlePioneer,
That's pretty much what I had in mind. There's a liner/pipe in the chimney now. I was figuring leaving it or something similar extended to the necessary height. This is a job well beyond my comfort level, so I'd leave it to a pro.
I'm just trying to figure out if that's what I really want to do. I feel like that metal pipe with proper rubber boot is going to be more reliable leakwise than my chimney and flashing that we seem to have to keep boo-boo patching.
Here's what I have now:
I was thinking of replacing it with something like this:
Just not sure how it'll look, or how tall it needs to extend past the roof deck. Obviously the taller the more out of place it'll be.
SeattlePioneer,
That's pretty much what I had in mind. There's a liner/pipe in the chimney now. I was figuring leaving it or something similar extended to the necessary height. This is a job well beyond my comfort level, so I'd leave it to a pro.
I'm just trying to figure out if that's what I really want to do. I feel like that metal pipe with proper rubber boot is going to be more reliable leakwise than my chimney and flashing that we seem to have to keep boo-boo patching.
Here's what I have now:
I was thinking of replacing it with something like this:
Just not sure how it'll look, or how tall it needs to extend past the roof deck. Obviously the taller the more out of place it'll be.
#6
10-31-15, 03:16 PM
Banned. Rule And/Or Policy Violation
Since you already have a chimney liner installed, it looks like you could remove the existing chimney brick by brick until it's below the roof level.
Then install some new roof sheathing to patch the hole, install a boot for the vent as it goes through the sheathing and re roof as necessary.
The general rule for the height of the vent is that the top of the gas vent needs to be two feet higher than any part of the roof within a ten foot radius of the vent.
The chimney in your picture seems to be within that ten foot radius, so it should extend 2 feet above the peak of the roof, which it should already do.
Then install some new roof sheathing to patch the hole, install a boot for the vent as it goes through the sheathing and re roof as necessary.
The general rule for the height of the vent is that the top of the gas vent needs to be two feet higher than any part of the roof within a ten foot radius of the vent.
The chimney in your picture seems to be within that ten foot radius, so it should extend 2 feet above the peak of the roof, which it should already do.
#7
10-31-15, 03:30 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
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Nice picture but it tells me nothing. I cannot see the details of the flashing nor can I see if you have a proper cricket on the up side of the chimney.
[ATTACH=CONFIG]58286[/ATTACH] (Image courtesy of NACHI.org)
[ATTACH=CONFIG]58286[/ATTACH] (Image courtesy of NACHI.org)
#8
11-01-15, 04:49 AM
The flashing is irrelevant for my question though. I just posted the photo to show the asthetics of it.
I'm looking to eliminate the whole chimney and replace it with a vent/cap. But trying to determine how high past the roof deck does it need to extend. If it has to extend past the peak of the roof, then it'll look stupid and I'll be forced to keep the chimney.
But to answer your question, there is no cricket like in your photo. Just step flashing down the sides, and little diverter wings that that extend 2-3 inches to either side on the top. But I think my water leakage is coming in between the brick and the flashing on the vertical surfaces.
I'm looking to eliminate the whole chimney and replace it with a vent/cap. But trying to determine how high past the roof deck does it need to extend. If it has to extend past the peak of the roof, then it'll look stupid and I'll be forced to keep the chimney.
But to answer your question, there is no cricket like in your photo. Just step flashing down the sides, and little diverter wings that that extend 2-3 inches to either side on the top. But I think my water leakage is coming in between the brick and the flashing on the vertical surfaces.
#9
11-01-15, 05:17 AM
I'm just a homeowner and am not able to answer your height question.
However, I too had a persistent leak from my chimney, and I too paid for a new roof that did not solve the leak.
1. Call a mason to inspect the mortar. A visit should not cost you anything, so what's the harm? I ended up paying my mason to repair the chimney cap, repoint the mortar, and to redo the roofer's flashing.
2. From the picture of your roof, I believe the flashing is parallel with the roof's slope rather than horizontal with the horizon? My mason placed the flashing so that it was horizontal, in a groove of the bricks. He argued that doing it this way made a better seal - makes sense to me.
3. Consider putting up siding overtop of the bricks. If it does turn out that your problem is with the mortar, my mason suggested this as a viable option to repointing the bricks. It could help to keep costs down.
I realize that I haven't addressed your basic question, but if you decide to keep the brick chimney, these thoughts may help. I had given up on roofers to solve my leak, but my particular mason had decades of experience. Good luck solving your leak. It took me two years to solve mine.
However, I too had a persistent leak from my chimney, and I too paid for a new roof that did not solve the leak.
1. Call a mason to inspect the mortar. A visit should not cost you anything, so what's the harm? I ended up paying my mason to repair the chimney cap, repoint the mortar, and to redo the roofer's flashing.
2. From the picture of your roof, I believe the flashing is parallel with the roof's slope rather than horizontal with the horizon? My mason placed the flashing so that it was horizontal, in a groove of the bricks. He argued that doing it this way made a better seal - makes sense to me.
3. Consider putting up siding overtop of the bricks. If it does turn out that your problem is with the mortar, my mason suggested this as a viable option to repointing the bricks. It could help to keep costs down.
I realize that I haven't addressed your basic question, but if you decide to keep the brick chimney, these thoughts may help. I had given up on roofers to solve my leak, but my particular mason had decades of experience. Good luck solving your leak. It took me two years to solve mine.
#10
11-01-15, 06:49 AM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
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Scoob, I'm trying to keep you from making a horrible mistake that will severely detract from the architectural design of your house. Without a proper cricket as well as a proper flashing job you WILL get rainwater down the outside of your chimney. Conversely, if you DO have a properly designed and installed cricket AND the proper flashing the chances of water intrusion at the chimney is extremely remote.
Yes, if you go to a stovepipe through the roof it DOES need to extend above the peak of the house, generally about three feet above the peak although sometimes a bit short will be okay. Without it being extended there is a pretty good chance of the wind hitting the roof slope and causing a "backdraft" in the stove pipe. The only other recommendation I can make is to replace your current furnace with a 90+% model that uses plastic vent piping out the side of your house.
When I had my roof replaced I had three professional roofing companies give me estimates. Only one recommended the installation of a cricket, guaranteeing me that if installed I would have no problems with leakage at that part of my roof. My point being, a lot of roofing companies would never even suggest it if you didn't point out the problem.
Yes, if you go to a stovepipe through the roof it DOES need to extend above the peak of the house, generally about three feet above the peak although sometimes a bit short will be okay. Without it being extended there is a pretty good chance of the wind hitting the roof slope and causing a "backdraft" in the stove pipe. The only other recommendation I can make is to replace your current furnace with a 90+% model that uses plastic vent piping out the side of your house.
When I had my roof replaced I had three professional roofing companies give me estimates. Only one recommended the installation of a cricket, guaranteeing me that if installed I would have no problems with leakage at that part of my roof. My point being, a lot of roofing companies would never even suggest it if you didn't point out the problem.
#11
11-01-15, 04:46 PM
Banned. Rule And/Or Policy Violation
Again --- the general rule is that a chimney or vent needs to extend two feet higher than any point withing a radius of ten feet.
#12
11-02-15, 05:32 AM
Thanks for the feedback guys. I guess eliminating the chimney probably isn't going the be the best route. That's why I love these communities. I wanted to bounce my idea off everyone and not just my contractor.
Before I hired the folks to reflash the chimney, I actually called a couple masons to check and possibly fix any morter joints. I'm convinced that rain water is running down the vertical surfaces and getting behind the flashing.
But I seem to have the worst luck with contractors. Either they'll never return my calls, or it's like pulling teeth to get them out to the house. Or they're just shady types that I end up hiring. LOL
Before I hired the folks to reflash the chimney, I actually called a couple masons to check and possibly fix any morter joints. I'm convinced that rain water is running down the vertical surfaces and getting behind the flashing.
But I seem to have the worst luck with contractors. Either they'll never return my calls, or it's like pulling teeth to get them out to the house. Or they're just shady types that I end up hiring. LOL
