Chimney Lining

[Jersey Devil]

I thought that I posted this question this AM but something went wrong.


Here goes again......who has relined a tiled chimney with the refractory cement systems that use a rubber flue liner "form" and a wet refractory cement mix surrounding the temporary rubber flue liner? I can't see myself just using a SS liner and getting a good service life compared to masonry.

Mike in NJ

 

[LeonMSPT]

A good chimney fire or two will change your mind. When the masonry starts spalling and cracking, and falling back down into the cleanout... Most of the liner systems out there are designed to take an extreme instance or two, as found in a chimney fire. The cheaper the system is, the less reliable it is, generally. Seen the tool they use on the end of a 1/2 inch drill to bust that stuff out and reline them... big chunk of steel plate, off centered, on a "bit" (piece of steel rod). They start at the top, and shovel it out the cleanout as it falls in.

I thought that I posted this question this AM but something went wrong.


Here goes again......who has relined a tiled chimney with the refractory cement systems that use a rubber flue liner "form" and a wet refractory cement mix surrounding the temporary rubber flue liner? I can't see myself just using a SS liner and getting a good service life compared to masonry.

Mike in NJ

 

[leaddog]

I had it done years ago after I had a bad fire. The problem I see with it is the liner isn't consitant in size so if you ever want to line it with an other metal liner you can't with out removing the old liner. Mine was oblong.
leaddog

 

[DaveBP]

This is a question I've wanted a convincing answer to for years.

An elderly friend of mine had her chimney relined with the SS liner last year and before I knew it I was right in there helping her with the grunt work to help her save some labor costs. Hers was an old brick chimney (no tile liner) with a couple minor but manageable doglegs in it. I don't see how the rubber hose/refractory cement system could possibly put a consistent thickness on the inside of a chimney like this. And without rotary sandblasting the whole inside what is it sticking to? We shoveled out buckets of crumbling mortar and brick dust just from snaking that liner down.
To complicate it this chimney was not square inside. So they walked on the 7" dia. liner to flattenize it a little and fed it down in. You know what you have with this stuff. Made of 316 Stainless welded together. Corrugated to make it flexible enough I don't think heat movement would make it warp. I think 316 is what they use for coal rated flues to take the sulfuric acid condensate.

So I guess the question I have on this subject is does anyone out there have one of these 316 snaked-in liners that has had a good old roman-candle chimney fire? Did it hold up? And I guess the corollary question is how do we know if it was damaged? The ash cleanout won't be filled with shards of ceramic liner like the poured-in stuff might.

 

[Jersey Devil]

Dave, you managed to restate my question better than I did. My exact sentiments. I know some said that...."what until you have a good ole fashioned cj=himney fire"...... but I'm afriad of what a "roman candle" chimney fire will do to SS as compared to masonry. The system that I saw had wire spacers that center the rubber flue form in the center so the pour thickness was consistent. My flue is big and straight so I'm not concerned about "wall thickness as much as the effect of a good fire. What happens to a SS joint that is warped to hell for instance and a fire will do something if not destroy or severlt damage a screw on joint.....no question in my mind.
.Mike

 

[LeonMSPT]

Stainless varies in quality and price. Which is what I was trying to say in my response. It's an impossible question to answer without knowing what system you're entertaining.

With a good to high quality liner, a chimney fire won't be that significant for the first two to three times. Continued extreme treatment is going to eventually destroy whatever material you line a chimney with. It doesn't matter what it is, stainless or masonry. Conversations I've had with professionals who have been doing it for a long time indicate that the poured in methods leave something to be desired in certain circumstances.

1. If there is no method to make sure, darned sure (100%), the "form" is centered in the chimney when the liner is poured, you're taking a chance on having very hot areas in various spots. Particularly at bends in the chimney, like offsets. If it's a straight shot, top to bottom, it's less of a concern but it's not irrelevant.

2. If and when you have a chimney fire or two, or three, what is going to happen to that poured in liner? If it is cracked and not serviceable, what will need to be done? I've seen the tool used to bust that stuff out of chimney's to replace them with stainless liners. Seems to me, if they were that great, that tool wouldn't exist or it would be awful rusty.

3. If a stainless liner is ruined, you pull it out, and reline it. No "jackhammer type thing" on the end of a 1/2 inch drill to bust it all out and shovel it.

In short. You got to do what makes you happy, once you've gathered as much information as you can. It's your chimney. Keep it clean, and burn reasonably, and you'll never find out what a chimney fire will do to it.

Dave, you managed to restate my question better than I did. My exact sentiments. I know some said that...."what until you have a good ole fashioned cj=himney fire"...... but I'm afriad of what a "roman candle" chimney fire will do to SS as compared to masonry. The system that I saw had wire spacers that center the rubber flue form in the center so the pour thickness was consistent. My flue is big and straight so I'm not concerned about "wall thickness as much as the effect of a good fire. What happens to a SS joint that is warped to hell for instance and a fire will do something if not destroy or severlt damage a screw on joint.....no question in my mind.
.Mike

 

[Jersey Devil]

Thanks Leon. What do they pour around a SS liner? Perlite maybe? Or does it just lay in the flue?

Mike

 

[LeonMSPT]

Lots of discussion on this in other posts over the time I've been around here, and in shops and coffee houses all across the snow belt.

My most sincere recommendation is a good quality "rigid liner" in the straight section of the chimney. To go through offsets into a fireplace, a good quality flexible stainless piece attached to the rigid section with stainless screws or rivets. Around the rigid goes a "snap fit" insultation that looks like "stovepipe", but has insulation between it and the inside liner. Around that, goes a blanket insulation, the entire length of the system from bottom to top, flexible included. This is usually "glued on" with 3M "High temp" spray adhesive. Around that goes a stainless steel "net" that looks like chicken fence, but functions like a "Chinese Finger Trap"... work it around the entire thing, then pull it tight on the liner.

With a high chimney, the only conceivable way I can think of would be to build it from the top, pushing it in as you make it... or hire a crane that can pick it up high enough to allow you to lower it into the chimney in one piece once it's together on the ground.

What has been described is a "Zero Clearance" chimney liner system. If there is creosote remaining in the old chimney, there will never be a fire between the liner and the old chimney. This has happened, and the results aren't pretty. As the top of the liner is sealed to the top of the chimney with a stainless plate (if done properly) it is airtight. Airflow is minimal through the old chimney, but it can get enough air to support combustion from below and around (especially in an old unlined chimney).

With the zero clearance system, you can put your hand on the outside of the liner anytime during a burn... not "hot", just warm.

Overkill? Depends on how much a person values peace of mind and safety. I place a premium on it when it comes to my house, and the houses of loved ones. Done two of them in the last 4 years. Takes a good day, sometimes two, to do it right.

Straight shot chimney lining job, top to bottom? Maybe a day, certainly not more. Makes a safe chimney that will likely withstand a roaring chimney fire or two, and not get too bent out of shape from a quick shot or two of high pressure fog from a Fire Department nozzle to smother the fire fairly quickly. We always tried to get to the top of the chimney with the ladder truck. Drop an old window weight down the pipe to bust a hole through to the bottom, and throw a couple of ziplock freezer bags of dry chemical extinguishing agent in there. Stick around until things cool off. Clean the chimney, and tell the property owner... "Should be fine now, light it up.", or "Condemned. Don't use it until it's lined properly and we come back. Should you choose to use it despite our recommendation, that will be in the report we send to the insurance company if we have to come back and put out what's left of your house."

I am unfamiliar with any masonry product that can withstand being heated to 2000 degrees, and then exposed to any quantity of water, without significant damage. There may be something out there. I haven't seen it. Without certainty regarding centering of poured in lining systems, and poured in insulation, my bet is with what I am certain is going to work.

Last one I did was 18 feet from fireplace insert to chimney top. Built it on the ground, twitched it up the ladder and roof, and stuck the thing down the chimney.

The stainless "net" is long enough... tied the end up with a weight in the bottom of it and threw it down the chimney ahead of the liner... helper grabbed it and used that to "pull" the liner as I pushed it down... wasn't what I would call, "easy" but was pretty doable.

Thanks Leon. What do they pour around a SS liner? Perlite maybe? Or does it just lay in the flue?

Mike

 

[sweetheat]

heatfab makes 304 and 316 stainless in 1', 2', 3', and 4' sections of straight wall pipe, plus all related parts and insulation. My chimney was a 12" square tile 34 feet up, I needed to have two different wood burning appliance in one flue and still be up to NFPA code. My fix was a 6"and 5" 304 stainless pipe side by side in the tile flue. We built a perch atop the roof and assembled it with pop rivits and lowered as we went, rope was necessary. sweetheat