New Chimney Melting My Vinyl Siding

[tae111]

I put up a new 8" Supervent stainless steel double wall insulated chimney last fall. I just noticed the vinyl siding behind it is starting to deform. I used their mounting kit and wall brackets. The chimney consists of a through the wall tee with six 36" sections above it. I also noticed that the first section off the tee is discolored and if you tap on it it rings like an oil drum. Behind that section is where the siding is melting. If you tap on the next section up you just hear a thud. Is it possible for the insulation in the pipe to degrade with the heat?

 

[Dmriggs]

View attachment 176061 View attachment 176060 I put up a new 8" Supervent stainless steel double wall insulated chimney last fall. I just noticed the vinyl siding behind it is starting to deform. I used their mounting kit and wall brackets. The chimney consists of a through the wall tee with six 36" sections above it. I also noticed that the first section off the tee is discolored and if you tap on it it rings like an oil drum. Behind that section is where the siding is melting. If you tap on the next section up you just hear a thud. Is it possible for the insulation in the pipe to degrade with the heat?

It seems to me that maybe that particular section, maybe doesn't have any insulation in it. Did you install the chimney yourself? I'm sure there would be a noticeable difference in weight between an insulated section and one without.
I would think it would take an extremely hot fire to burn the insulation to the point of no insulating properties at all!
Hopefully one of the experts will chime in on this very important issue shortly!

 

[saskwoodburner]

I would quit burning immediately, and get a professional in to assess the situation. You know how when someone leaves the barbecue too close to a house and the siding melts or starts warping? Whatever is going on is much too hot to be happening there.

Is it my eyes, or is the chimney color changed permanently to golden/straw color from the heat?

How far is your chimney away from the siding? Might give someone smarter than me a ballpark for the temps being reached.

 

[Dmriggs]

Possibly an undetected chimney fire at some point maybe? Hmmm

 

[double-d]

Just by looking at the lower pipe, it may have been over fired, and that is also the area where the siding is melting. I doubt that the insulation is missing or fallen down.

 

[kennyp2339]

After looking at the pics very closely I'm leaning towards an undetected chimney fire also, looking at the discoloring of the pipe you could see how the first (2) lengths from the bottom going up had the high temp discoloration, I would pull the cleanout cap and look up the pipe to see if the insulation intact, also if the center pipe is still smooth and not bowed out.

 

[tae111]

It seems to me that maybe that particular section, maybe doesn't have any insulation in it. Did you install the chimney yourself? I'm sure there would be a noticeable difference in weight between an insulated section and one without.
I would think it would take an extremely hot fire to burn the insulation to the point of no insulating properties at all!
Hopefully one of the experts will chime in on this very important issue shortly!

I did install it myself and didn't notice any weight difference.

 

[tae111]

Possibly an undetected chimney fire at some point maybe? Hmmm

Maybe but I didn't notice one. I called the manufacturer, Selkirk, and he said the chimney was supposed to stand up to chimney fires and the clearance of their mounting kit should protect the house. I had the house sided last fall and right before I did that I replaced the chimney that was there since 1984 (same model chimney) I was concerned about the vinyl siding at that time but could find nothing on the internet that said it would be a problem. I also couldn't find anyone selling a mounting system that held the chimney further away from the house. My stove is a Consolidated Dutchwest large model that I put in in 1984. Cast iron with a catalytic combustor. This year we burned only Envi 8 blocks. These are made from pressed hardwood floor (oak) dust and chips. Only water and pressure used in making them. The moisture content is close to zero so the creosote formation is way less then regular seasoned wood. I do clean the chimney out after every cord or ton on this case and I am able to keep the stove temps the same as burning split wood. In the 30 years that I had the old chimney I did have a few small chimney fires that crept up the chimney. When I took it down there was no evidence of damage inside though.

 

[tae111]

I would quit burning immediately, and get a professional in to assess the situation. You know how when someone leaves the barbecue too close to a house and the siding melts or starts warping? Whatever is going on is much too hot to be happening there.

Is it my eyes, or is the chimney color changed permanently to golden/straw color from the heat?

How far is your chimney away from the siding? Might give someone smarter than me a ballpark for the temps being reached.

I did stop burning as soon as I noticed it

 

[tae111]

The chimney is a class A solid pack and has a 2" clearance requirement to combustibles. I have 2 3/4" with my set up. I also used the outside wall brackets and hardware that Supervent sells for this installation.

 

[MishMouse]

The bottom part of the pipe should not be that color. Some event either major over fire or chimney fire must have happened. I would not burn it until an expert has reviewed the setup and an inspection has been made.

 

[webby3650]

My first guess would be that you had a bunch of buildup in the tee and it caught on fire.

 

[jetsam]

Vinyl siding usually has a very low melting point- I've seen 160°F quoted as a general rule of thumb.

Find and fix the problem that led to the pipe being that hot first- maybe a creosote issue leading to chimney fire, maybe a gasket issue leading to overfires, whatever.

If you want to repair the siding, you may want to consider running a different product up behind the chimney. If it was me, I might get some J channel and end the siding run nicely to either side of the pipe, and put in Hardieplank or regular cement shingles. You can take a piece of the siding to Home Depot and ask them to colormatch it, so you can paint the cement siding the same color as the vinyl.

Plain old cement shingles are cheap and come in 2' width, which is probably a good size for that. I've never installed Hardieplank but I have heard good things about it.

 

[tae111]

My first guess would be that you had a bunch of buildup in the tee and it caught on fire.

That maybe the case but should that destroy the chimney section. I would think that these chimneys are constructed so that they could stand up to pretty high heat. When I tap anywhere on that first section it sounds like tapping a empty paint can now. If you tap on the tee or the next section up you just hear a thud. would the heat be high enough to disintegrate the insulation?

 

[tae111]

Vinyl siding usually has a very low melting point- I've seen 160°F quoted as a general rule of thumb.

Find and fix the problem that led to the pipe being that hot first- maybe a creosote issue leading to chimney fire, maybe a gasket issue leading to overfires, whatever.

If you want to repair the siding, you may want to consider running a different product up behind the chimney. If it was me, I might get some J channel and end the siding run nicely to either side of the pipe, and put in Hardieplank or regular cement shingles. You can take a piece of the siding to Home Depot and ask them to colormatch it, so you can paint the cement siding the same color as the vinyl.

Plain old cement shingles are cheap and come in 2' width, which is probably a good size for that. I've never installed Hardieplank but I have heard good things about it.

Thanks I was thinking of doing something like that. I already have the colormatch paint. I am going to take the chimney down to that section and replace it.

 

[tae111]

I did stop burning as soon as I noticed it

And yes it did change color from the heat

 

[Dmriggs]

Thanks I was thinking of doing something like that. I already have the colormatch paint. I am going to take the chimney down to that section and replace it.

 

[begreen]

It does look like something wrong happened there. Was the tee cap loose or not sealing right at some point? An air leak at the tee can cause rapid cooling of the flue gases. My guess would also be a chimney fire. This should be inspected by a certified sweep to verify current safety.

 

[Dmriggs]

There are at least a couple of professional chimney sweeps that, frequent these forums. I hope one of them at least, will pop on here. I'm glad to hear you plan on dismantling and replacing the affected sections but, I know it's not an easy endeavor.
I've only experienced one chimney fire and caught it quickly. I've read though that they can burn hot enough to warp or collapse the inner liner of double wall pipe so, I guess, it may be possible to incinerate the insulation. I would think it would have to burn at a real high temp for an extended amount of time though. I don't have the details but, I remember reading that double walled insulated pipe should withstand like 1100 degrees for like an hour.

 

[Xtrl9]

.... This year we burned only Envi 8 blocks. These are made from pressed hardwood floor (oak) dust and chips. Only water and pressure used in making them. The moisture content is close to zero so the creosote formation is way less then regular seasoned wood....

Just in case you were unaware these things burn hotter because of that. How many and how were you loading them in your stove?

 

[webby3650]

That maybe the case but should that destroy the chimney section. I would think that these chimneys are constructed so that they could stand up to pretty high heat. When I tap anywhere on that first section it sounds like tapping a empty paint can now. If you tap on the tee or the next section up you just hear a thud. would the heat be high enough to disintegrate the insulation?

I don't think this one event would or should damage the pipe. Multiple flue fires can though.
It's really odd that it sounds different when you thump on it too.

 

[webby3650]

Vinyl siding usually has a very low melting point- I've seen 160°F quoted as a general rule of thumb.

Find and fix the problem that led to the pipe being that hot first- maybe a creosote issue leading to chimney fire, maybe a gasket issue leading to overfires, whatever.

If you want to repair the siding, you may want to consider running a different product up behind the chimney. If it was me, I might get some J channel and end the siding run nicely to either side of the pipe, and put in Hardieplank or regular cement shingles. You can take a piece of the siding to Home Depot and ask them to colormatch it, so you can paint the cement siding the same color as the vinyl.

Plain old cement shingles are cheap and come in 2' width, which is probably a good size for that. I've never installed Hardieplank but I have heard good things about it.

Ive seen multiple times where the reflection from a window next to a vinyl sided fireplace chase actually melts the siding. It's pretty flimsy stuff! If it wasn't for the messed up chimney section I wouldn't be all too alarmed.

 

[mellow]

I find it odd that you would have a chimney fire burning compressed wood bricks in a cat stove, are you monitoring your flue temps? Seems to me the cat bypass/damper was left open and it burned really hot. Can you post some pics of your stove and stove pipe setup inside?

 

[tae111]

Just in case you were unaware these things burn hotter because of that. How many and how were you loading them in your stove?

Yes I am aware of that and turn the air down on the stove to compensate for that. I have 3 thermometers. 2 on each top corner of the stove and one on the stove pipe. Also on this stove there is a thermometer in the top plate of the stove right above the catalytic combustor. Even though the stove could be running between 300 and 400 degrees the catalytic thermometer usually runs between 750 and 1000 degrees. I don't ever load more than 6 bricks at any one time.

 

[AmbDrvr253]

I find it odd that you would have a chimney fire burning compressed wood bricks in a cat stove, are you monitoring your flue temps? Seems to me the cat bypass/damper was left open and it burned really hot. Can you post some pics of your stove and stove pipe setup inside?

I have to agree. I do not believe one event caused this type of discoloration. Unless it was an 8 hour event......