stove pipe questions

[fireinmybelly]

hello, i'm installing my first wood stove, chimney & hearth. i'm still waiting on my englander 17-vl wood stove from home depot so i'm tackling all the other plans, decisions, purchases, etc.
what is the replacement time frame for the double stove pipe? i see that the single stove pipe is to be replaced every 3-5 years. (is that really the time frame when folks here replace theirs?) i bought 24 gauge imperial single wall snap lock stove pipes from lowes and understand i need to connect the stove pipes & connectors using furnace cement & sheet metal screws. do i use 1/2"stainless steel metal screws to attach stove pipe joints? do i seal the stove pipe seams and connectors with furnace cement, then screw the joints or the other way around? can someone give me a link to the exact metal screws i need (size & other details). i appreciate your patience with this wood stove newbie.

 

[soupy1957]

I understand "do it yourself" but there are good reasons to hire a "Professional" to do this:

A) Your Home Owners Insurance will give you a discount if you can prove it was "Professionally" installed.
B) You don't have to be concerned about (with a reputable company that is) "what materials are correct."
C) You can sleep easier at night, knowing that you have a "safe" system (relatively speaking).

-Soupy1957

 

[jimbom]

Three #10 sheet metal screws per joint. Fit of the screw to the hole is important. Make sure the screw has to work a little to get home. That will insure a tight joint in an extreme event. Strength is not really an issue. The structural loads on a stove pipe assembly are far less than the strength of the pipe fastener connections. Stainless is great, but will not color match the stove pipe.

 

[Backwoods Savage]

Welcome to the forum fireinmybelly.

Replacement of stove pipe 3-5 years???? Maybe for some folks but that stuff can last a whole lot longer than that. If my memory is correct, when we bought our Ashley stove, that single wall pipe was still the original pipe when we took the stove out...over 20 years later. The only reason we took it out was we did a complete new chimney and only had to have 1 piece of pipe and because it is black pipe, we wanted a new good looking piece. The old pipe was still fine.

When I install stove pipe I use furnace cement in each joint and then use self tapping screws (#8) 3 per joint.

As for Soupy's suggestion, that can be good for some folks but for such a simple thing as stove pipe I don't see any advantage of hiring that done. Maybe some insurance companies would require it but I don't know of any that do. On our insurance, the only requirement was to have a false wall and they know we did it ourselves because the agent happened to stop as we were installing it. All was well.

 

[oldspark]

My single wall stove pipe is over 30 year old and still looks new, the 3 to 5 year thing must be some cheap stuff or they are trying to sell you something.

 

[oldspark]

The snap lock stuff is that what you have to put together, if it is it sucks, go with heaviest welded stuff you can get.

 

[soupy1957]

............................Maybe some insurance companies would require it but I don't know of any that do. .....................

Point of clarification, if I may.........I wasn't suggesting that an Insurance company would "require" that a Professional install your system. Only that some Insurance companies will charge you more than you need to pay, if it is installed by a non-professional. I've heard this directly from an Insurance Rep..

-Soupy1957

 

[raybonz]

hello, i'm installing my first wood stove, chimney & hearth. i'm still waiting on my englander 17-vl wood stove from home depot so i'm tackling all the other plans, decisions, purchases, etc.
what is the replacement time frame for the double stove pipe? i see that the single stove pipe is to be replaced every 3-5 years. (is that really the time frame when folks here replace theirs?) i bought 24 gauge imperial single wall snap lock stove pipes from lowes and understand i need to connect the stove pipes & connectors using furnace cement & sheet metal screws. do i use 1/2"stainless steel metal screws to attach stove pipe joints? do i seal the stove pipe seams and connectors with furnace cement, then screw the joints or the other way around? can someone give me a link to the exact metal screws i need (size & other details). i appreciate your patience with this wood stove newbie.

My original stove pipe was the cheap snap lock seam stuff and was 20 yrs. old and still solid but the new stuff we have now is much better (broken link removed to http://www.woodstove-outlet.com/woodstove/blk622pipe.htm) but more expensive.. This stuff is so strong you could stand on it.. Worth the $$ in my opinion..

Ray

 

[jebatty]

...the cheap snap lock seam stuff and was 20 yrs. old and still solid but the new stuff we have now is much better ... but more expensive.

Seems to me that pipe that lasts 20 years and still is solid, although cheap, makes much more expensive pipe an exercise in throwing money out the window for the fun of it. Our "cheap snap lock seam" pipe has seen 21 winters of 24/7 burning in the cold, northern MN climate, and is solid with no evidence of corrosion or wear, also no smoke leakage and no seam sealing with furnace cement, etc. Also use the same for the Tarm in the shop, 4 years of burning, and it too is solid with no evidence of corrosion or wear.

 

[raybonz]

...the cheap snap lock seam stuff and was 20 yrs. old and still solid but the new stuff we have now is much better ... but more expensive.

Seems to me that pipe that lasts 20 years and still is solid, although cheap, makes much more expensive pipe an exercise in throwing money out the window for the fun of it. Our "cheap snap lock seam" pipe has seen 21 winters of 24/7 burning in the cold, northern MN climate, and is solid with no evidence of corrosion or wear, also no smoke leakage and no seam sealing with furnace cement, etc. Also use the same for the Tarm in the shop, 4 years of burning, and it too is solid with no evidence of corrosion or wear.

Jim it was worth the price for peace of mind if nothing else.. The corrugated elbows are extremely strong as well and it goes together very nicely with no stove cement with a positive feel to the connections.. I did have a chimney fire and had to replace my clay liner (my insurance paid for everything) and I feel this pipe would endure much better if something went wrong.. I have one slip pipe, one 90, one 45 and one 1 foot section of this heavy duty stuff and it was under 100 bucks total.. Short money compared to everything else .. I figure this will be the last stove pipe I will ever buy..

Ray

 

[oldspark]

I suppose there are better versions of the snap lock stuff, some of it is really thin stuff that probably is only good for 3-5 years, I think the double wall stuff is what is the overpriced pipe, I can not believe what they get for that stuff and I see no advantage other than clearance. I dont think most people have enough stove pipe for it to have an effect on the draw of the chimney.

 

[begreen]

Double wall pipe is stainless inside and with a bonded outer shell. There a lot more steps to manufacture it.

The advantages of double-wall have been posted numerous times. For some folks it makes the difference between a stove that barely drafts and one the drafts sufficiently.

 

[Backwoods Savage]

............................Maybe some insurance companies would require it but I don't know of any that do. .....................

Point of clarification, if I may.........I wasn't suggesting that an Insurance company would "require" that a Professional install your system. Only that some Insurance companies will charge you more than you need to pay, if it is installed by a non-professional. I've heard this directly from an Insurance Rep..

-Soupy1957

Good point Soupy

 

[oldspark]

Double wall pipe is stainless inside and with a bonded outer shell. There a lot more steps to manufacture it.

The advantages of double-wall have been posted numerous times. For some folks it makes the difference between a stove that barely drafts and one the drafts sufficiently.

Am well aware of the claims, and have read about people spending a fortune buying double wall pipe and two 45's vs a 90 and it still not helping. My point was that if you have just a few feet (lets say 6ft or less) that double wall will not have a noticable effect on the draw and I stand by that.

 

[begreen]

Well, we'll just have to agree to disagree. 4ft of pipe going up to a 90 and 2 ft going to a thimble can equal a lot of heat loss.

 

[fossil]

Find yourself some of these screws, if the color's important to you:

http://www.google.com/products/cata...i=e-AhTsvBMI74sAOCyJA6&sqi=2&ved=0CFQQ8wIwAQ#

Could be available locally, otherwise you can easily order them online from any of a number of sellers. Rick

ETA: If you look around a bit, you can find the same fasteners in a philips head screw if you prefer that.

 

[oldspark]

Well, we'll just have to agree to disagree. 4ft of pipe going up to a 90 and 2 ft going to a thimble can equal a lot of heat loss.

It would be nice to know for sure, spending that much extra money for nothing is not fun. Have not been able to come up with any thing on line about it. Does the fact that the double wall is some what air cooled have an effect on the flue temp?

 

[begreen]

The air layer acts as an insulation to the flue gases. I'm heading out now, but if you dig you will find threads where folks compared flue temps before an after. They noted a large measurable difference. A hundred degree increase in flue temps entering the thimble can mean the difference between creosote condensing at the top to the stack or not. That's partly why some stove makers recommend not using single-wall for a connector over 6-8'.

 

[fossil]

Double wall stovepipe provides considerably more insulation from ambient for the flue gas stream as compared with single wall stovepipe. So with double wall, the flue gases will remain hotter as they travel up toward daylight...which is a good thing, as it will help to minimize the condensing out of creosote in the flue. My little shop stove has a vertical run of single wall stovepipe with a double-45° offset. Total from stovetop to ceiling supprt box of about 6½ feet. Couple years ago I got curious about heat loss up the stack, so I put a second magnetic thermometer ~4' above the one I run just above the flue collar (the second one was just above the offset). It's surface temp, of course, not internal flue temp, but it's a qualitative indicator. My stovepipe temp dropped nearly 200°F in that 4' of single wall. Yeah, I got a little more heat out into my shop off the stovepipe...but that's what the stove's for. Looking at the stove/flue as an integrated system, I think I'd be better off overall with double wall stovepipe. This year or next I'm planning to swap it out. Rick

 

[oldspark]

I think if you are having draft problems it could help and I see your side of it, I guess it depends on your install, my new chimney will be straight up no elbows with only about 4 or 5 ft stove pipe so I can not justify the extra cost (22 gauge single wall aint really cheap either). The claims (by stove pipe manufactors) that you have to change out single wall stove pipe every 2 to 3 years left me skeptical of their claims.

 

[begreen]

That's a short connector and you are probably right, for that setup, double-wall may not make a large difference. Is there a cathedral support box that it is tying into? As you know, the Summit needs a minimum 54" clearance to the ceiling.

 

[oldspark]

67 inches to the ceiling from top of stove, by the time I tie into the support box I will have 58 inches of stove pipe, I guess if I ever build a hearth for it I will have to have a heat shield on the ceiling.

 

[jebatty]

Comments raised an interesting observation for me regarding possible creosote from too low of flue temp. I have 9 feet of single wall black stove pipe from the flue outlet on the Tarm to the ceiling connection to Class A. Typical interior flue temp at 18" above the flue outlet is 425F. When I cleaned the chimney late spring after a full heating season, there was only a light coating of dust inside the Class A and a little heavier coating of dust inside the black stove pipe. No creosote or drippings anywhere. Appears evident that whatever cooling is taking place in the black stove pipe is not causing a problem in the Class A or elsewhere.

 

[Todd]

Double wall stovepipe provides considerably more insulation from ambient for the flue gas stream as compared with single wall stovepipe. So with double wall, the flue gases will remain hotter as they travel up toward daylight...which is a good thing, as it will help to minimize the condensing out of creosote in the flue. My little shop stove has a vertical run of single wall stovepipe with a double-45° offset. Total from stovetop to ceiling supprt box of about 6½ feet. Couple years ago I got curious about heat loss up the stack, so I put a second magnetic thermometer ~4' above the one I run just above the flue collar (the second one was just above the offset). It's surface temp, of course, not internal flue temp, but it's a qualitative indicator. My stovepipe temp dropped nearly 200°F in that 4' of single wall. Yeah, I got a little more heat out into my shop off the stovepipe...but that's what the stove's for. Looking at the stove/flue as an integrated system, I think I'd be better off overall with double wall stovepipe. This year or next I'm planning to swap it out. Rick

So how does your chimney look when you clean it? Are you having a problem with creosote with all that single wall?

I can see where a long run of single wall pipe could be a problem but I don't think a short 4-6' single wall section will make much difference unless you have an overall short chimney.

 

[begreen]

Exactly. The flue is the engine of the fire. With EPA stoves running cooler flues, it helps to keep the flue temps hot, all the way to the top. For many installations, as long as clearances are safe, single wall is fine. But if the draft is marginal due to a short flue or a cold exterior chimney, double-wall can help.