Contractor says chimney is impossible to add liner to!

[tunaman4u2]

Had a contractor say he couldn't line my chimney for a wood stove yesterday! My exterior chimney goes straight down a 7x7" terracotta lined flue. The stove needs a 6" flue minimum. There already is a 8x8 hole leading right into the flue in my marble backsplash. His reasons for not even trying to install the liner are:
1. 90 deg T piece wouldn't fit down the flue & there would be no way to attach it to the pipe above it
2. Flex pipe wont go 90 deg.
3. There wouldn't be any way to clean the debris over time that falls into the trap

Has this happened to anybody? The chimney was built with the house in 1983 & has never been used. Now someone is telling me its impossible to line? I never expected this. Any thoughts on how to get around that 90 deg angle? My plan was to use the Simpson duraliner since its a straight shot.

To be honest I may be forced to use a pellet stove into the unlined chimney if Mass code allows that.
Thanks guys,
The Tunaman

 

[granpajohn]

All the hype about steel liners sometimes make people forget that terra cotta is a liner also. I think your chimney is allowable under code.

p.s. This post in the Boiler Room, but you did say stove.

 

[tunaman4u2]

Why didn't the contractors say that? I had TWO of them yesterday! You just can't trust anyone anymore. I'll call my local Fire Dept & see what they say but if they clear that as a liner I'm going to pick up a clearance 30" englander wood stove this week!
I'll keep yall posted.
GO CELTICS! What a come back!
Mike

 

[MrEd]

May want to check with the building inspector, not sure if the fire department has any real knowledge on this matter. In my town (also in Mass) the building inspector is the one to inspect wood appliances, not the fire department. BI will cite you code, FD will give you an opinion.

 

[webbie]

Sounds like some BS!

First of all, as others have said, the chimney may be up to snuff anyway.

Next case - if you do have to line it the lining companies make Tees with removable snouts, designed exactly for what you want to do. Rigid pipe, BTW, is smaller on the outside than flex- so it may work better for your situation.

OH, if the simpson is pre-insulated, that may not be good - it has a larger OD and may not fit. Use single wall if you are gonna line it. Then, if you are going to insulate (probably not needed), you can use a pourable mix.

As to cleaning, there are a number of ways to accomplish that. If the chimney already has a clean out, then you may be able to leave the bottom of the tee open and the soot will fall. Another way is to cap the bottom of the tee and then remove the interior black pipe when you need to clean. This is not a big deal with modern stoves that may only need cleaning once a year.

 

[BrotherBart]

The contractors can see your chimney and I can not, but they are probably right about getting a tee down it. Both me and forum member Todd had the same problem. Six inch liner just wouldn't go down a 7" X 11" inside diameter terra cotta flue. When I went with a 5.5" liner the two piece tee main body still would not fit down the flue. Todd and I both put the 5.5" flex pipes down the flues without tees and gently turned the liners 90 degrees into the crocks at the bottom. It is slow tedious work to do it. From the bottom, with good gloves on you turn the liner into the crock an inch at a time while somebody up top gently pushes down on it. The main problem with this approach is you have to have a 5.5" to six inch adapter to attach the stove pipe at the thimble inside and they are real hard to find and you have to trim a six inch brush to 5.5 for cleaning.

But truth be told with a 7 X 7 tile lined flue in good shape I would burn into it without a SS liner for a season to see how it draws.

PS: If you measure the hole in the top plate of a 30-NC below the welded flue collar it is exactly 5.5" where the exhaust comes through the top plate.

 

[gpcollen1]

Where are you still getting an Englander on clearance?

 

[Hearthman]

The chimney must be suitable for the class of service. That is determined by a Level II inspection. Just because there are flue tiles in there does not mean the chimney is "lined". Those tiles must be in serviceable condition. Moreover, there are joints every 2 feet that are usually compromised. The chimney must have proper clearances along with many other things, which are included in the level II inspection.

Don't assume or guess--get it inspected.

A liner for solid fuel must be insulated per the listing to meet the 2,100F rating. How much insulation is needed is determined by the level II inspection. IF you have a 1" airspace all the way down the chimney, you may be able to use the thinner insulation but regardless, you have to insulate that liner. To get a 6" liner with insulation down a 7"x7' flue will probably require removal of the old tiles first to make room.

FYI, you cannot vent a pellet stove into an unlined chimney. Pellet stoves vent under positive vent pressure. Masonry chimneys are designed or approved for positive vent pressure.

HTH,
Hearthman

 

[blackgooseJT]

Thank you hearthman. The free advice often sought for its economy carries a hidden cost, that is lack of liability.Public servants are immune from liability in most states and cases. If they give you bum advice its just your tough luck. Likewise sight unseen advice from the internet carries no liability. Use it at your own risk. Understand that part of what you pay a licensed, fully insured contractor to do is to assume liability for his work. If the contractor hired to do the job (and the proper level inspection and documentation) says that your system needs attention maybe you should listen. Of course you can always rely on your neighborhood firefighter to help put out the fire that proper attention could have prevented.

blackgooseJT

 

[stoveguy2esw]

7X7 (provided the terra cotta is servicable) falls within the range allowed by code for a stove with a 6" flue opening. unless the liner is cracked or damaged somehow and the chimney is built to code there should be no reason to line it unless you just want a SS liner.

 

[BrotherBart]

In my unlicensed, Internet opinion kooP I think he meant to say "Masonry chimneys are designed or approved for negative vent pressure."

 

[fraxinus]

Another possible option is a poured in place liner. Supaflu (www.supaflu.com) is one system among two or three more. Supaflu is based in Scarborough, ME and is generally available throughout New England. I was very satisfied with my installation.

 

[BrotherBart]

Good point frax. I would love to have one of those poured liners.

 

[Hearthman]

Whoops! Typo--I meant to say masonry chimneys are NOT designed for positive vent pressure. That means furnaces, water heaters, pellet stoves, boilers, etc. all must be natural draft to vent into a masonry or factory built chimney. The only venting approved for positive flue gas pressure is UL 1738 listed stainless steel or glued PVC. Even current pellet vent, listed to UL 641 is not approved for positive pressure. This is being addressed by UL STP 103 soon. There is one liner just listed to UL 1738, which is made by Pro-Tec. Thx,

Finding a masonry chimney that was "built to code" is a bit like looking for unicorns. However, if you do find one built to the applicable code at that time and can still pass an NFPA 211 level II inspection, then you do not have to reline it. However, the liner does several things for you:
sizes the flue to the appliance
contains the flue gases and condensates
heats up very quickly for a stable draft (thin stainless liners--poured liners heat up slowly but once heated are great for draft)
easier to sweep in general
provide 2,100F protection against chimney fires
backed by a mfr. with a lifetime warranty (some transferrable)

Cast liners, such as Supaflu, can substantially strengthen a marginal chimney. However, if the chimney is too weak, you could get a blowout and dump a truck load of oatmeal into someone's bedroom (refractory cement). If the bladder is deformed, so will the liner be. You need to remove the flue tiles in order to install the pumped liner so it can handle the hoop stress and thermal shock. However, properly installed pumped liners in stable chimneys in non-seismic zones that are used for extended burn times perform very well.

BTW, what is the warranty on a masonry chimney?
What temperature is the flue tile tested and listed to?

If you cannot verify those clearances to combustibles then plan on a listed liner.
Hearthman

 

[tunaman4u2]

Thanks guys.

Maybe I should have been more clear... I don't think I have terracotta because there are no tile. Maybe its solid clay liner sort of like this...

http://www.superiorclay.com/flue-liners.php

I called Dura-vent today as well & they said the solid T piece comes apart AND I can fit 6" insulated pipe down my 7" chimney because the outer diameter is 6 5/8". Tight but doable.
So why do 2 contractors not even know the parts they carry? Ridiculous!

My next step is to talk to the town building inspector directly & ask him what passes for code. I'll update the board with that info too. Maybe the clay liner is enough. Maybe I don't need insulated pipe with the clay liner. Maybe I can do the install myself since the contractors around me are fools.

As for the Englander stove theres a home depot that has 2 left. Just call em all until you find em. Pellet stoves aren't on clearance, just the wood stoves.

 

[stoveguy2esw]

Whoops! Typo--I meant to say masonry chimneys are NOT designed for positive vent pressure. That means furnaces, water heaters, pellet stoves, boilers, etc. all must be natural draft to vent into a masonry or factory built chimney. The only venting approved for positive flue gas pressure is UL 1738 listed stainless steel or glued PVC. Even current pellet vent, listed to UL 641 is not approved for positive pressure. This is being addressed by UL STP 103 soon. There is one liner just listed to UL 1738, which is made by Pro-Tec. Thx,

Finding a masonry chimney that was "built to code" is a bit like looking for unicorns. However, if you do find one built to the applicable code at that time and can still pass an NFPA 211 level II inspection, then you do not have to reline it. However, the liner does several things for you:
sizes the flue to the appliance
contains the flue gases and condensates
heats up very quickly for a stable draft (thin stainless liners--poured liners heat up slowly but once heated are great for draft)
easier to sweep in general
provide 2,100F protection against chimney fires
backed by a mfr. with a lifetime warranty (some transferrable)

Cast liners, such as Supaflu, can substantially strengthen a marginal chimney. However, if the chimney is too weak, you could get a blowout and dump a truck load of oatmeal into someone's bedroom (refractory cement). If the bladder is deformed, so will the liner be. You need to remove the flue tiles in order to install the pumped liner so it can handle the hoop stress and thermal shock. However, properly installed pumped liners in stable chimneys in non-seismic zones that are used for extended burn times perform very well.

BTW, what is the warranty on a masonry chimney?
What temperature is the flue tile tested and listed to?

If you cannot verify those clearances to combustibles then plan on a listed liner.
Hearthman

GLUED PVC!?????????? we are talking woodstoves here

 

[tunaman4u2]

Who does the 211 inspections? Town or fire department?

The house was built in 1983 & this chimney flue has never been used. Wonder if with the clay it could pass inspection just with a thimble from the wood stove.

Interesting. I just have to find THE person that does this code. The contractors had NO clue at all.

 

[BrotherBart]

It is one of those cute things you run into. The house with chimney was built and if the occupancy inspection was done 10 years or 10 minutes ago somebody "in the business" always says "Nobody can guarantee that it was built to NFPA 211 spec so it is crap and if you don't let us put in an insulated liner your family will die.".

One of the things I liked about this Forum for a long time was that the pros that dropped in didn't dump on the homeowners like happens in the HVAC forums and newsgroups. Well, times change I guess.

Craig, who owns the Forum, knows first hand that there are a lot of under spec chimneys our there but doesn't condemn them all out of hand. And he was in the business a long, long time.

 

[webbie]

An ID like that - and an age like that - would almost guarantee that the chimney is already lined! Terra-cotta is just one name for "flue tiles" which are made of fired clay.

A very close fit can be dangerous! You might get 1/2 way down and then get stuck!

Personally, I would first have a local building inspector or fire dept (some do this)...or chimney sweep, inspect the flue and tell you whether it is OK as is. If it needed lining, I would probably use single wall without insulation due to fit issues. This would effectively give you double lining - the existing flue tile and then the ss.

If you see orange or red tile sticking out the top.....then it is lined.

 

[tunaman4u2]

Webmaster!

All you say sounds so true. The 2 contractors I had come by gave me no info. Lets hope the building inspector says I can get away with a single wall pipe. It does sound like no matter what you are recommending a SS liner in addition to the clay liner I have.
I check out the Englander stove tonight. Sweet!

 

[fossil]

Webmaster!!

(Aside - He prefers to be addressed as "Obi-Wan Kanstovey". Rick)

 

[Hearthman]

Bart, that is an unfair characterization. I am talking about the legal aspects of this. If you are under the International Building Code, as one example, then the chimney must meet the class of service. The chimney may be a 200 yr old unlined flue but once under building codes, when you make a change, you are legally obligated to follow the code. Nobody is saying flat out you will die without a liner. Failure to pass a Level II inspection simply means it no longer meets the current standards. We learn more and more over time as people have fires and problems. What do you want us to do, not improve the codes as we learn from past mistakes?

As for who should inspect the chimney, the building inspector, fire dept, and many sweeps are not qualified to inspect chimneys. Maybe they were 20 yrs ago when that's all we had but we now have Certified Fireplace Inspectors who are trained.

If you do reline a chimney, the codes Require you to use a listed liner (no stove pipe) and it be installed in accordance with the listing, meaning insulation. To do otherwise could void the warranty on the stove and liner, cause cancellation of your homeowner's insurance and put occupants at risk. If you relined without insulation and there was an unfriendly fire, the excuse about not fitting would be used to indicate a lack of concern for the well being of the homeowner and possibly gross negligence. This is not fear mongering but based upon real world cases.

Bart, I resent your tone suggesting I am dumping on homeowners. I am simply trying to provide you with current accurate information based upon industry standards. If you choose to ignore those stds. that is your decision. However, when giving advice on a public forum, you should temper your thoughts with the public trust. Maybe you should be a little more concerned about trivializing the matter.

As for how many chimneys out there are substandard or do not meet code, let me share something with you: When I used to be a member of the National Chimney Sweep Guild, I was the Chairman of the Technical Advisory Cmte. I polled the membership to see who had ever seen a single chimney that met any code 100%. Two responded in the affirmative---they both were masons who poured the foundations and layed every brick themselves. Other than that, they seem to not exist. So, all chimneys will have some defects. Does that mean the house will burn down? Not necessarily. It does mean it does not meet current standards or what we now know about chimneys. If you want to roll the dice and use a questionable chimney that is your perogative. However, understand the liability that attaches.

As for who performs the inspection and their pronouncing a chimney acceptable or not, that is an engineering opinion. A professional inspector simply states facts on the present conditions as compared to current codes and standards--period.
Hearthman

 

[BrotherBart]

Hearthman have you ever inspected a chimney that you passed without modification/improvement?

 

[Hearthman]

I don't pass or fail chimneys---I inspect them. Have I ever found a single chimney that did not have some sort of issue? No. Have I found any that ever met 100% of the applicable building code? No. Have all these chimneys burned the house down? No. Have some of these chimneys caused water damage to the home or allowed the release of noxious fumes into the home? Yes. Have I seen unfriendly fires from woodstoves vented into masonry chimneys with terra cotta flue tiles? Yes.

Since no one answerd my quiz, the answers are:
there is no warranty on a masonry chimney
there is no temperature testing on terra cotta flue tiles per the ASTM C-315 std. to which they are made.

Now Bart, how many chimneys have you inspected and what are your professional qualifications?


Mike, I referred to glued PVC to illustrate the point about pellet venting--it must be pressure tight. I was not saying use PVC for wood. The UL 1738 std. is for Cat. IV high efficiency condensing gas furnaces--not woodstoves or pellet stoves.
Hearthman

 

[webbie]

HearthMan......maybe you are new here, but I detect a similar tone to one FireplaceGuy who stopped by here in the past.......

Calling out our members in the first couple posts will not get you a gold star!

As to "professional" qualifications, please don't make me laugh! I see new orgs coming into existence regularly and each thinks they know-it-all. Most of us know how to read NFPA, and we have been through 200,000 posts here from engineers, designers, manufacturers, building officials, chimney sweeps, dealers, mechanical contractors and many more folks well versed in their trades. We also have some combustion engineers........

My advice:
1. Hang back a bit - get to know us...figure out if this is the place for you. If it isn't your "bag", then don't fight it - we ain't gonna change much.
2. Have a Natural lite with BB
3. Spend some time lobbying the government to outlaw flue tiles and masonry chimneys. As of now, they allow them.

We are just people helping people here......none of us claim to be experts, rather we are always learning.