Oversized storm collar

[Chas0218]

So I installed a wood stove at the end of the summer and made sure the chimney with the cathedral ceiling box was sealed really good on the roof. Lots of roofing tar underneath to get a good weather proof seal along with trimming shingles to perfectly fit around the flashing. It took me longer to install than it should have but it was done right and thoroughly.

It has been about 1 month and he checked on the house for me and found the chimney to be leaking now the amount of water looked like it had a small amount of water on the top of the stove and a little that ran down the leg and onto the hearth that spot was maybe 3" in diameter but on the top of the stove it was a good amount that has caused it to start rusting.

I'll throw up some photos tonight but in the meantime do they sell a larger over-sized storm collar? The stove is installed in our cottage and we get heavy winds with rain which is how I suspect the stove got wet. I am thinking of adding an over-sized storm collar to help combat the wind. Also how close should the storm collar be to the flashing? The flashing has the oval vents in it which I would imagine are supposed to be open to allow air circulation. My biggest concern is the cathedral box filling with snow then when I fire the stove in the winter I'll have buckets raining down onto a hot stove and worse my brand new hardwood floors.

Any links or suggestions would be greatly appreciated.

 

[Highbeam]

If you used tar then you didn't do it correctly. If you shingled it properly (won't know until we see pics) then the biggest cause of leaks is that you didn't leave a half inch gap between the cone and the edge of the shingle. Trimming the shingles perfectly tight against the cone is a leak causer, the gap allows the water to run around the cone. Another common mistake is putting exposed nails along the bottom edge of the flashing. Gooping more tar on those nails is at best a band aid.

No goop, a gap around the cone, and no exposed nails.

The storm collar can be set all the way down against the cone but I like to leave a half inch of gap. There is a method to installing that collar too. First ring the chimney with silicone, then slide the collar down into it, then apply silicone to the top of the collar where it meets the pipe as well as the lap joint.

Folks have had leakage from the actual side seam of the class A pipe too.

I hate roof leaks.

 

[Chas0218]

If you used tar then you didn't do it correctly. If you shingled it properly (won't know until we see pics) then the biggest cause of leaks is that you didn't leave a half inch gap between the cone and the edge of the shingle. Trimming the shingles perfectly tight against the cone is a leak causer, the gap allows the water to run around the cone. Another common mistake is putting exposed nails along the bottom edge of the flashing. Gooping more tar on those nails is at best a band aid.

No goop, a gap around the cone, and no exposed nails.

The storm collar can be set all the way down against the cone but I like to leave a half inch of gap. There is a method to installing that collar too. First ring the chimney with silicone, then slide the collar down into it, then apply silicone to the top of the collar where it meets the pipe as well as the lap joint.

Folks have had leakage from the actual side seam of the class A pipe too.

I hate roof leaks.

No the flashing was done correctly I have to use tar underneath the shingles otherwise the wind will lift and rip them off. Also all nail heads were gooped otherwise I would not have flashing left if I didn't nail down the bottom edge. The cottage is very exposed and the wind is brutal in Northern NY on the NE end of Lake Ontario. On calm days the wind is usually in the mid teens on rough days your looking at 40mph-50mph just blasting the cottage. It looked like the water was coming in from the cathedral box/pipe.

I did not seal the collar so I suspect that is the issue. What type of silicone would be best? I have some of the high temp stuff used on car engines that resist oil and heat. Would that be ideal vs the clear stuff.

I will be replacing the roof with steel next year so the goobered nails just have to last the rest of this season until I replace the flashing with the steel roof flashing

 

[Babaganoosh]

Not sealing the collar is almost definitely the problem.

 

[Chas0218]

Not sealing the collar is almost definitely the problem.

Guess I learned my lesson here.

 

[kennyp2339]

When I installed my class a through the roof I used regular silicone and hit all the seams of the class a (vertical) I had an extra attic insulation shield (same thing as a storm collar but bigger) and used that, again silicone that

 

[Highbeam]

When I installed my class a through the roof I used regular silicone and hit all the seems of the class a (vertical) I had an extra attic insulation shield (same thing as a storm collar but bigger) and used that, again silicone that

If water made it into the attic I think I would rather it cling to the pipe and run down onto the stove top than spread out into the attic framing to slowly rot the wood and damage sheetrock. I might even install that second storm collar upside down as a funnel to direct any problems toward the pipe.

 

[Highbeam]

No the flashing was done correctly I have to use tar underneath the shingles otherwise the wind will lift and rip them off. Also all nail heads were gooped otherwise I would not have flashing left if I didn't nail down the bottom edge. The cottage is very exposed and the wind is brutal in Northern NY on the NE end of Lake Ontario. On calm days the wind is usually in the mid teens on rough days your looking at 40mph-50mph just blasting the cottage. It looked like the water was coming in from the cathedral box/pipe.

I did not seal the collar so I suspect that is the issue. What type of silicone would be best? I have some of the high temp stuff used on car engines that resist oil and heat. Would that be ideal vs the clear stuff.

I will be replacing the roof with steel next year so the goobered nails just have to last the rest of this season until I replace the flashing with the steel roof flashing

60 mph is no big deal. I live in a high wind area near a gap in the cascade mountain range, every year we exceed 80 mph. As such, the permitting authority made me use the "high wind" installation methods which just means 4 nails per shingle. The shingles already have the tar strip. No matter though, you are going to metal and it sounds like you found your problem.

That storm collar must be sealed to the pipe so that the umbrella effect channels water away from the top of the cone. The moderator here recommended GE silicone 2 which is available in clear at home depot and looks good there on the SS pipe. For good measure, you can run a small bead up the vertical seam of the class A but I have never had that leak. The temperature of class A in free air has not been high enough to damage the silicone in the experience of me or the other folks here.

Just don't use red RTV. I've seen it and it looks crazy. I know what the guy is thinking, high temp, but it looks bad.

 

[Chas0218]

60 mph is no big deal. I live in a high wind area near a gap in the cascade mountain range, every year we exceed 80 mph. As such, the permitting authority made me use the "high wind" installation methods which just means 4 nails per shingle. The shingles already have the tar strip. No matter though, you are going to metal and it sounds like you found your problem.

That storm collar must be sealed to the pipe so that the umbrella effect channels water away from the top of the cone. The moderator here recommended GE silicone 2 which is available in clear at home depot and looks good there on the SS pipe. For good measure, you can run a small bead up the vertical seam of the class A but I have never had that leak. The temperature of class A in free air has not been high enough to damage the silicone in the experience of me or the other folks here.

Just don't use red RTV. I've seen it and it looks crazy. I know what the guy is thinking, high temp, but it looks bad.

Haha the red stuff is the first thing that cam to mind but I was going to go with the black stuff. I was thinking I cold put a big bead around the top of the flashing then press the storm cap onto the flashing and seal both at once then run a nice bead around the seam on top of the storm cap.

 

[Highbeam]

I was thinking I cold put a big bead around the top of the flashing then press the storm cap onto the flashing and seal both at once then run a nice bead around the seam on top of the storm cap.

No need to seal the cone to the pipe. Just the storm collar to the pipe. Put the first, big, bead an inch or so higher than the top of cone and as you slide the storm collar down into it the bead will roll down and almost be scraped clean from the pipe but properly piled under the storm collar. Once level, that is important, then wipe any leftovers from the pipe and then apply that top bead neatly.

 

[begreen]

Regular GE Silicone II is fine for caulking the storm collar seam. It is clear and stands up very well to the weather. Our storm collar seal still looks great after 9 years of burning. The silicone remains soft and flexible. Class A pipe does not get extremely hot on its exterior unless there is a sustained chimney fire.

 

[kennyp2339]

If water made it into the attic I think I would rather it cling to the pipe and run down onto the stove top than spread out into the attic framing to slowly rot the wood and damage sheetrock. I might even install that second storm collar upside down as a funnel to direct any problems toward the pipe.

Hmm.. maybe your right, perhaps there is more of problem than a unsealed storm collar.

 

[Babaganoosh]

Seal it first. Then observe during the next rain storm, or better yet use the garden hose to test it. Go from there. That's what I'd do.