# Discolored Metal Roofing



## jhambley (Dec 14, 2013)

I just started burning my new BlazeKing Princess that was professionally installed. After about four days of continuous use, I'm noticing a light brown discoloration below the SS chimney pipe on my white metal roofing. Should I be worried or is this normal?


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## begreen (Dec 14, 2013)

Sounds like creosote dripping. How far above the roof it the chimney cap? Is the stove connected with double-wall connector pipe?


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## jhambley (Dec 14, 2013)

The stove is connected inside the house with a straight run of black stove pipe up to the ceiling collar and then changes to SS double wall the rest of the way out. The pipe is about 5' above the roof penetration and about 2' from the ridge of the roof. I don't think it's dripping because it's down a couple of feet below the roof penetration. Almost like it drifted down to the roof. 

Another issue was the sprayed foam insulation (open cell) that was blown on the inside of the roof decking. The insulation contractor sprayed the foam in direct contact with the double wall SS pipe at the roof collar. I questioned him during the install and he assured me it was fine to spray directly on the collar and pipe. I have since read that the foam must stay a minimum of 3" away from any heating device flue or exit. I just stripped that insulation off and I could see several pieces of foam were discolored at the joints of the pipe.


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## Hogwildz (Dec 14, 2013)

Cut the foam minimum 2" from the piping. I would go 3" just to be safe.


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## jhambley (Dec 14, 2013)

Hogwildz said:


> Cut the foam minimum 2" from the piping. I would go 3" just to be safe.


 
Thanks I already removed the foam 3+" back from the pipe. I'll look into Rockwool or Roxul.


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## begreen (Dec 14, 2013)

Is the stove connected with single wall pipe? BK recommends double-wall to keep flue temps higher.


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## jhambley (Dec 14, 2013)

begreen said:


> Is the stove connected with single wall pipe? BK recommends double-wall to keep flue temps higher.


They installed black pipe from the stove to the ceiling collar (about 6' of straight black pipe) The rest of the pipe is all SS insulated.


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## NRGarrott (Dec 15, 2013)

Do you have any pictures of it?


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## jhambley (Dec 18, 2013)

NRGarrott said:


> Do you have any pictures of it?


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## Lumber-Jack (Dec 18, 2013)

That picture isn't very clear, but I don't see any sign of a typical chimney flashing?
Can you get a clearer picture close up at the base of the chimney/roof area.


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## Nick Mystic (Dec 18, 2013)

Do you think the stain you are seeing can be rust? You have a steel roof that is treated to inhibit rust, but once you cut a hole in it you create a raw edge that will rust if it is exposed to moisture. Can you get on the roof for a close look? If it is rusting from the edge of the hole you can probably fix the problem with a liberal bead of high quality silicone caulk.


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## jhambley (Dec 21, 2013)

Nick Mystic said:


> Do you think the stain you are seeing can be rust? You have a steel roof that is treated to inhibit rust, but once you cut a hole in it you create a raw edge that will rust if it is exposed to moisture. Can you get on the roof for a close look? If it is rusting from the edge of the hole you can probably fix the problem with a liberal bead of high quality silicone caulk.



It's not rust because it wasn't there until I started using the stove about a week ago.


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## begreen (Dec 21, 2013)

Lumber-Jack said:


> That picture isn't very clear, but I don't see any sign of a typical chimney flashing?
> Can you get a clearer picture close up at the base of the chimney/roof area.



Agreed. Where is the flashing and storm collar?


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## jhambley (Dec 21, 2013)

The 


begreen said:


> Agreed. Where is the flashing and storm collar?



The collar in under the white metal roofing and then they silicone caulked around the penetration. I didn't think the silicone would hold up and would eventually start leaking so I just ordered a Dektite #8 Silicone Hi-Temp Pipe Flashing that I'll have installed when it arrives.


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## Lumber-Jack (Dec 21, 2013)

jhambley said:


> The
> 
> 
> *The collar in under the white metal roofing *and then they silicone caulked around the penetration. I didn't think the silicone would hold up and would eventually start leaking so I just ordered a Dektite #8 Silicone Hi-Temp Pipe Flashing that I'll have installed when it arrives.


Storm collars do not go under the roofing.


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## Lumber-Jack (Dec 21, 2013)

Here are a couple examples of what the flashing and storm collar should look like.
As you can see the flashing is clearly visible in both cases, and the storm collar is the collar that fits tight at the top and widens at the bottom to help shed the water away from the chimney. There is no way the storm collar could work properly if it was "under the metal roofing".


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## jhambley (Dec 21, 2013)

W


Lumber-Jack said:


> Storm collars do not go under the roofing.



I just climbed up into the attic again to look how the insulated chimney pipe passes through the roofing. It looks like they cut the plywood back about 2-3 inches from the pipe and then cut the white metal roofing very close around the insulated pipe. They then sealed the small crack between the pipe and roofing with clear silicone caulking.  That's the area I'm worry will eventually leak so I've order the Dektite collar (see image). He brought out a moldable aluminum storm collar that he said they could install but almost everyone he had installed on seamed metal roofs ended up leaking because they couldn't be hammered tightly enough to fit the roofing.


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## jhambley (Dec 21, 2013)

Just a note that the Dektite #8 I ordered was good for pipes up to 13". Hopefully that's large enough for the insulated pipe I have (6" flue).

Regardless of the flashing, I'm still not sure why I'm seeing a faint, brown discoloration on the south side of the stove pipe. It appears that the exhaust is falling back onto the roof surface.


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## Lumber-Jack (Dec 21, 2013)

jhambley said:


> W
> 
> then cut the white metal roofing very close around the insulated pipe. They then sealed the small crack between the pipe and roofing with clear silicone caulking. * That's the area I'm worry will eventually leak *so I've order the Dektite collar (see image).
> .


You can count on it leaking the way they left it. You basically don't have any flashing or storm collar.
That Dektite collar should work if you get it sealed properly. It would still be a good idea to install a standard metal storm collar over top the Dektite collar, similar to the second photo in my last post. If you put a bead of silicon around the chimney and push the storm collar down onto the silicon bead it will seal it up water tight and any water running down the chimney will shed away. That is the purpose of the storm collar


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## jhambley (Dec 21, 2013)

Thanks Lumber Jack. What outside diameter is a 6" double wall insulated pipe?


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## sticks (Dec 21, 2013)

typically 8"


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## Lumber-Jack (Dec 21, 2013)

jhambley said:


> Regardless of the flashing, I'm still not sure why I'm seeing a faint, brown discoloration on the south side of the stove pipe. It appears that the exhaust is falling back onto the roof surface.


As begreen said, it is likely creosote dripping of your chimney pipe.


begreen said:


> Sounds like creosote dripping. How far above the roof it the chimney cap? Is the stove connected with double-wall connector pipe?


This can happen if you are burning wet wood, burning your fires too cool, or if it is cold and windy outside and the wind cools your chimney cap enough that the smoke condenses on it and drips off.
It is certainly not an ideal thing. If it continues it will stain your roof much worse and the creosote is corrosive and could eventually eat the finish off your metal roofing.
Make sure your wood is as dry as possible, and try to burn as cleanly as possible.



jhambley said:


> Thanks Lumber Jack. What outside diameter is a 6" double wall insulated pipe?


6" (inside diameter) + 4" (of wall material thickness _(2" each side sides_) = 8"   So you should be fine with that Dektite if it good for pipes up to 13".


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## begreen (Dec 21, 2013)

Good to see you ordered the  Dektite silicone (red) booting. What is supporting the pipe inside? A ceiling support box?


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## jhambley (Dec 21, 2013)

Cold and windy conditions are all we have in Kansas 

I've checked the wood with a moisture meter and it's fine. Following BlazeKing's firing instructions.

I'm wondering if replacing the black stove pipe (about first 6') with insulated pipe would help keep flue temperatures higher? The rest of the pipe used is insulated and all in interior/conditioned space before penetrating the roof.


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## jhambley (Dec 21, 2013)

begreen said:


> Good to see you ordered the  Dektite silicone (red) booting. What is supporting the pipe inside? A ceiling support box?



Yes, there is a support collar/box at the 9' ceiling penetration where the single wall changes to double wall insulated.


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## jhambley (Dec 21, 2013)

The BlazeKing is cruising on "2" and I measured the flue temperature right above the stove collar at 289 and 115 at the ceiling collar (6' higher). Seems like a lot of temperature drop in that single wall pipe. Could this be my problem?


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## begreen (Dec 21, 2013)

This is why Blaze King recommends double-wall pipe. You are getting the efficiency from the stove. The stove pipe should not be used to scavenge the last iota of heat with these stoves.


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## weatherguy (Dec 22, 2013)

Why are these installers not installing according to BK's specs? Seems to cause problems of one sort of another in some cases and it could probably be avoided.


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## Hogwildz (Dec 22, 2013)

Looks like rust to me. Once the metal is cut, especially steel, it will rust, especially under the silicone.


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## jhambley (Dec 22, 2013)

begreen said:


> This is why Blaze King recommends double-wall pipe. You are getting the efficiency from the stove. The stove pipe should not be used to scavenge the last iota of heat with these stoves.



It drives me crazy how little most of these "professionals" know about the products they sell. They didn't even know what a BlazeKing was even though they were listed as an authorized reseller on the BlazeKing site. Store manager had to call headquarters to find out that they even sold the BlazeKing line. When their installer showed up with the stove I quickly read through the installation manual and saw BlazeKing's recommendation that all stove pipe be insulated. I pointed this out to the installer but was told that such a short run of single wall wouldn't make any difference in performance.

Next, the "professional" foam insulation company sprays foam directly on the stove pipe in the attic. I questioned him and was told it was perfectly fine. Only later do I find out that there should be at least 3" of clearance between insulated pipe and foam.

Just examples of the customer paying for the seller's/installer's ignorance. 

I really like this BK stove, I just need to fix all the issues caused by the "professionals".


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## Matt Ruggeri (Dec 22, 2013)

Rust. My friend has that same roof on his building, and it was installed poorly. I'll help him change out the gasketed screws every now and then, we can always find the ones that leak by following the rust trail running down the roof. Every now and then we'll have a new screw that leaks, Can usually find it because it will have the rust trail after one rain. 
Whoever installed your Chimney without flashing and weatherproofing it should be smacked around with that Dektite when you get it! And the excuse of "they'll always leak" is either laziness, or lack of skills.


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## Lumber-Jack (Dec 22, 2013)

I would still like it if you could post a close up (clear) picture of that roof penetration area and the "rust".


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## jhambley (Dec 22, 2013)

Lumber-Jack said:


> I would still like it if you could post a close up (clear) picture of that roof penetration area and the "rust".



It's covered with ice and snow at the moment  I did have some slightly discolored icicles hanging from the cap this morning (we had freezing rain and snow last night) so I ran the stove on high to take the stove pipe temps up. Seems to have cleared the ice.


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## mark cline (Dec 22, 2013)

Rust won't discolor icicles , you are not burning hot enough . Even seasoned wood (20 % moisture or less ) will still cause creosote at low temps . Surface temp of your black pipe should be minimum of 250F.


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## jhambley (Dec 22, 2013)

I'm burning Hedge so burning hot is not the challenge. The flue temperatures at the collar are hot but they quickly cool in the single wall pipe when measured just before the ceiling collar. Anyone know how much difference I should see if I replace the single wall with double wall?


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## mark cline (Dec 22, 2013)

OK,  If your burning hot enough , then you need that heat all the way up the pipe . Where ever it cools , you will get creosote condensing on the pipe and it will drip.


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## Motor7 (Dec 23, 2013)

I understand you are going to fix the storm collar issue yourself, but I would still go in and complain about it and demand double pipe at their expense. 

You may not want to hear this, but even if you are burning proper wood and have those other issues fixed a light colored roof is a bad choice for a wood burner. The flue cap is always going to catch any un burnt material in small quantities and it gets deflected down onto the roof. In my opinion you can minimize it, but there will always be some residue seen on that white roof. I have to ask, did you pick a white roof, or was it there when you bought the house? I don't see many white steel roofs at all.


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## begreen (Dec 23, 2013)

The discoloration is creosote, not rust. Note that is extends even onto the panel section where there is no cut. Someone just posted a more dramatic example of how this gets on the roof and looks. 
https://www.hearth.com/talk/threads/my-chimney-took-a-crap.120353/


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## Lumber-Jack (Dec 23, 2013)

begreen said:


> The discoloration is creosote, not rust.* Note that is extends even onto the panel section where there is no cut. */


What picture are you looking at that you can clearly see that???


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## begreen (Dec 23, 2013)

the one posted here:
https://www.hearth.com/talk/threads/blazeking-double-wall-stove-pipe-question.120332/#post-1611315


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## Lumber-Jack (Dec 23, 2013)

Ah, yes. That's a way better picture. Definitely creosote. Thanks BG.


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## Lumber-Jack (Dec 23, 2013)

That creosote is corrosive, if he doesn't clean that up and do something to prevent it from continuing to happen, it will end up corroding the metal surface and "rusting".


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## Hogwildz (Dec 23, 2013)

Good eye BG.
Well that brings us back to the wood maybe, or just normal condensation and dripping for winter time.
I don't have locust, but am thinking it takes longer than a year to dry.
Someone can correct me if I am wrong?


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## jhambley (Dec 24, 2013)

So...where to start considering the wood is not the issue?

1. Replace first 6' single wall with double wall?
2. Extend exterior pipe a couple of feet higher above the roof ridge?
3. Could a different rain cap help at all?


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## Phoenix Hatchling (Dec 24, 2013)

Lumber-Jack said:


> As begreen said, it is likely creosote dripping of your chimney pipe.
> 
> This can happen if you are burning wet wood, burning your fires too cool, or if it is cold and windy outside and the wind cools your chimney cap enough that the smoke condenses on it and drips off.
> It is certainly not an ideal thing. If it continues it will stain your roof much worse and the creosote is corrosive and could eventually eat the finish off your metal roofing.
> ...



eh.....6 + 4 = 10.


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## Lumber-Jack (Dec 24, 2013)

Phoenix Hatchling said:


> eh.....6 + 4 = 10.


Damn!, I knew I should have used my calculator. 
  Oh well, I never was very good at math.


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## Hogwildz (Dec 24, 2013)

It might just be condensation which is dripping off the cap to the roof. Nothing you can really do about that.
White roof while good for reflecting sun & heat, is not the best choice of color.
White anything on a house, never stays white.
The flashing is your main issue, or lack thereof actually.
I don't think there will be a simple solution to the stained roof.


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## begreen (Dec 24, 2013)

In a few years a white roof would be green on the north side of the house out here. Moss grows in the darndest locations. 

jhambley, I would start with changing out to double-wall pipe to fall better inline with the mfg. recommendations.


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## Lumber-Jack (Dec 24, 2013)

Hogwildz said:


> I don't think there will be a simple solution to the stained roof.


Actually, one of the nice things about painted metal roofs is you can wash it off easily. Providing you get to it before it corrodes the paint too much.


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## firefighterjake (Dec 24, 2013)

Hogwildz said:


> It might just be condensation which is dripping off the cap to the roof. Nothing you can really do about that.
> White roof while good for reflecting sun & heat, is not the best choice of color.
> White anything on a house, never stays white.
> The flashing is your main issue, or lack thereof actually.
> I don't think there will be a simple solution to the stained roof.



Honestly, I was thinking it may have bee just that . . . condensation dripping from the cap since it seems like it is just a bit discolored.


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## Treacherous (Dec 25, 2013)

begreen said:


> In a few years a white roof would be green on the north side of the house out here. Moss grows in the darndest locations.



Definitely on the west side... my old cabin on the east side had a 40 year old white metal roof... I replaced it this last summer with a "white" raised metal seam roof.  The general dryness on this side kept the moss and green away over the years.  It stands out some but keeps things cool in the summer.  Everything else is the typical green or red roof with a random blue around me.


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## begreen (Dec 25, 2013)

Yup, green is the safest color here on the west side of the Cascades. The roof is going to have a coating of moss sooner or later unless you zinc it.


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## Treacherous (Dec 25, 2013)

begreen said:


> Yup, green is the safest color here on the west side of the Cascades. The roof is going to have a coating of moss sooner or later unless you zinc it.



If this new roof starts to show any green I might have to zinc it.  The last one was over 40 years old and was only a faded white so may not have to worry about it.  The snow in the winter probably scrapes off what moss could form.  Not a lot of that over on this side.  

Fully aware of the green and moss on west side.  My home roof has it's share on the north side.


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## brokenknee (Dec 25, 2013)

That is similar to what was installed on my new metal roof this summer. Still don't have the wood stove installed, but have had no problems with leaks. Copied the picture from Lumberjacks post. Mine is currently covered under about 18" of snow.


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