How check if chimney is good

Bob Harper

See my comments on the 24th about Z-flex...

FireDragon: Ventinox is a great quality liner. However, they are not bullet proof. I know sweeps who have had to replace them and Martin was not very responsive to say the least.
Olympic's Forever Flex and Cooperfield's ProFlex are about as well made as any liner I've seen and both can take incredible abuse such as pulling around corners and offsets without separating. Yes, you can drill them, too without unravelling. So what are you getting from Ventinox for >$100.00 more? At least the other warrant their products. They also respond to the market making adapters that fit and half sizes we need. Ventinox used to be king but got complacent and was left in the dust by innovation.

Tom_22

What look for? Drop a light down there?

My house is 98 years old and I had a couple of small pieces of the clay flue liner fall down the chimney. Should I reline the chimney with a stainless steel liner or is this not too big a problem? I use oil heat now but am going to convert to natural gas soon.

What's a good way to inspect the chimney and what should one look for? Lower a drop light down it maybe? The chimney is 4' high and the roof is flat so it's easy to work with now.

But a house was built abutting mine but one story taller so the contractors are going to build my chimney about 10' higher to go 4' above their roof. If I need to reline it, I think I ought to do it now before the chimney gets taller and harder to work with.

michael_15

There should be a cleanout

near the bottom. A flashlight and a mirror I think is a good way to peek up the chimney. If there's no cleanout, see if you can remove the lowest duct venting into the chimney, and just stick your flashlight and mirror in there instead.

-Michael

jim lockard

Liner

Tom - from what you have stated I would line the chimmney. Have the liner sized to your heating equipment by a HVAC contractor or a chimney sweep. Best Wishes J.Lockard

Ken_8

Stick a mirror into the

lowest opening (probably have to remove the boiler vent/smoke pipe) and near midday - when the sun is high overhead, hold the miror in the darker cellar on a 45° angle and look up the chimney via the mirror. It's amazing how much detail you can see with this method. If its cracked and has voids, line it. Better yet, switch to a condensing boiler and fawgettabowtit. You don't need a chimney with a condensing boiler.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Bob Harper

teaching chimney inspection online?

No offense but we cannot teach chimney inspections online anymore than we can teach HVAC installation or service online.

You know you have damage to the flue. The flue can no longer perform its intended function and therefore must be relined. If you convert fuels, you need an NFPA 211 Level II inspection. NFPA 31 and 54 require relining when connecting new appliances if the chimney does not meet 211 Stds. Since there are no 211-compliant chimneys in America except a literal handful built by sweeps, all need liners.

If you're still worried, hire a sweep to perform the Level II inspection.
HTH,

Tom_22

What ought I look for in a liner?

jim lockard

Liner

Tom-- Flex-ell and others make liners for your chimney, you may get by with a aluminum liner for Nat.Gas but I would spend the extra bucks and have an all fuel stainless steel liner dropped down your chimney. I agree with Bob we can not inspect your chimney or explain how its done from a keyboard. So call in a Pro to check it out. Best Wishes J.Lockard

Bob Harper

liners

I would not waste my money on an aluminum liner. Even down South, the condensation can eat them up in short order. I'd stick to 316Ti or AL29-4C alloys. There are many brands and methods for fabricating liners. There is one popular brand sold through HVAC supply houses that is notorious for unravelling and corroding. It is in 321 alloy, which is made for high temps-not so much corrosion.

Call your local sweep to discuss it. If you are extending the chimney, you can use inexpensive chimney blocks followed by the liner if the chimney is or can be downsized to about 16" square. The stucco it.
You can also transition from the old chimney to B-vent but then you have to stabilize the stack.
HTH

Tom_22

AL29-4C for gas burners

I saw somewhere on the web, I think it was here: http://www.homesaver.com/homesaver_chimney_liner.asp, that AL29-4C was the only recommended material for gas burning equipment.

Bob Harper

liner alloys

AL29-4C was developed by Allegheny-Ludnum for Battelle Labs when they experimented with various alloys for use in heat exchangers of higher efficiency equiment. 29% chromium/ 4% molybdenum. This super alloy will stand up to even condensing furnaces so if your equipment is above 83% AFUE, AL29-4C is the better alloy. However, if you look at the test data, 316Ti is close behind it. For most atmospherically vented appliances, 316Ti is fine and some give it a Forever warranty! I usually reserve the AL29-4C for horizontal venting

Sooty Bob at Copperfield Chimney Supply is doing what all the other liner guys are doing--just trying to make a buck. HomeSaver is a good liner. I prefer Olympic's Forever Flex. Michigan Chim Flex is good,too. Ventinox is way over priced and Martin hasn't responded to the market with certain diameters, fittings, etc. The advent of 5.5" liners has been a Godsend in those tight 7x7 flues that aren't stacked perfectly plumb.

Tom_22

I got a good look at it from the top with a flashlight. I didn't check it myself from the bottom yet, but I will.

Tom_22

I had a chimney sweep look at it today. He said he wanted to knock out all the clay flue tiles because they a lot of them have shifted and are offset from each other (true, I saw it myself) and getting a big enough flue wouldn't be possible now because of that. The existing flue is 7x7 ID or about 8x8 OD I think. He also said he would put in the biggest liner that would fit, probably 10". That part didn't sound right to me. He noted the existing vent coming out of the boiler is 9" but connects to a 10" horizontal going to the chimney, so 10" would probably be right for the liner. (I think that horizontal pipe might be 12", but I didn't check that.) The existing boiler is an American or United States model (I forget, I have the nameplate and it is hardly readable. It must be about 50 years old and is a big boiler. House has 16 rooms plus hallways.

I think the flue he wants to put in might be too big for the Burnham Independence 7 natural gas fired steam maker and 75gal High Output Hot Water Heater I will be putting in soon. The Burnham calls for a 7" flue and the HWH probably needs a 4". I don't know how to figure the right size for the combination of the two.

The sweep wanted $7000 to do the job. There's about 34 feet of flue. He's including taking down the deteriorated brick chimney and rebuilding it from the roof line up to it's existing 4' or so and putting a cap on it.

I think I'll do this job myself. I can handle the brick chimney rebuild easy. I do that as part of my regular job anyway. It was the relining part I wasn't thinking of getting involved with until I heard his price.

Tom_22

I took a better look at that building next door to me today. It is a good 12' from the top of my chimney to the top of their parapet and they have a big brick chimney 30" higher than that a couple of horizontal feet away. So I'll have to go at least even with their chimney which means I have to go up another 15' from where mine is now.

I think I'll go with a metal stack for this extension. I don't like building a masonry chimney up that high on top of the one I have now. It's only a single row of bricks all around and it's old. It seems like too much weight on those old bricks and mortar joints.

Tom_22

I checked out those other manufacturers products Bob. I like the Thermix product a couple of them recommend. That might be good for tightening up my old chimney.

Bob Harper

Thermix

was developed for wood burner liners to pass the 2,100F UL 1777. It is recommended but not required. If your chimney is really weak and not too far from needing to be rebuilt, Thermix can strengthen it. Thermix is siliconized vermiculite w/ Portland cement. It makes a light wt. concrete. K factor is 0.43 per inch, which is really good. Allow for the moisture to escape or else you could blow the chimney apart with steam.
HTH

Tom_22

Hi Bob,
I met with three different sweeps to look at lining my chimney. None of them were familiar with Thermix or had ever used it before.

It sounds like a good product and I suspect the mortar joints on my 98 year old chimney are probably not real bad, but might not be the best.

I didn't find out how much Thermix costs yet, but it doesn't look like it would be terrribly expensive.

What is the proceedure for allowing the moisture to escape?

Tom_22

Liner size

Hi Jim,
Two of the sweeps who looked at my chimney suggested an 8" liner and one suggested a 7". The 7" guy gave the best price by far. I didn't have as good a feeling about him in general either though. Him putting a big black mark on one of my walls with his dirty hand for instance.

I was told the bigger the liner the better. I was a little surprised at this as I imagined that an oversized chimney might reduce the speed that the exhaust goes up, but I was told that the bigger the chimney, the better the draft.

Bob Harper

where are you located?

Maybe I can help find a sweep for you. Sweeps that don't know about Thermix is scary. I guess all they do is simple heater relines and leave the rest for the competition.

Thermix is labor intensive. Who's going to mix it (wearing a respirator) then haul buckets of it up a ladder & dump it down the chimney?
SaverSystems makes these stainless steel vent tubes for the moisture. You could also cover the top with a plate that's not siliconed down allowing it to breath out the top for a month or so then come back and seal it. Actually, after a week, most of the water has wicked out of the mix enough to fire it up on high. If you're just running a water heater into it you shouldn't have to wait the week.

Tom_22

Hi Bob,
I'm in the Sunset Park section of Brooklyn, NY. I could also be reached at ReleaseThePrisoner@yahoo.com

vhlaundry

What about Z-Flex?

Jack_21

Basically...

if you are venting a modern appliance, whether gas or oil, you should not use an unlined masonry chimney, IMHO, of course. Masonry chimneys are excellent architectural devices but very poor mechanical devices. they are a complete waste of money in new homes, other than for the traditional look.

Firedragon_4

I disagree

with the statement on Ventinox.

Any liner that you can drill a hole into for testing or other reasons without falling into a million pieces is hardly 'overpriced', JMO!

gerry gill

you keep wanting a sweep,

to line the chimnney, how come you dont ask the contractor who is going to replace your boiler? i'm sure he/she has run into bad chimnneys on boiler replacements..just a thought.