Custom Masonry Heater - advice needed

[jfgros01]

Hey Folks,
We recently moved into a home with a custom built soapstone masonry heater, circa 1988. My guess is that it was a heavily modified tulikivi kit based on the design features. I was not able to obtain design or as built drawings of the unit. My family just adores this heater. The heat it gives off is incredible.

This year, we had a cleaning and inspection that revealed several small cracks in the terracotta flue. I started reaching out to masons and chimney repair companies to see about fixing this. Most turned me away simply based on the design of the flue. The issue is that this unit was designed with a flue damper, which is built in the the parged CMU chimney wall. Apparently, this is no longer acceptable in the fire code. So this is not as simple as dropping in a new SS liner. Other companies rejected the idea that we can simply replace the terracotta liner without addressing current code violations.

The current contractor I'm talking to is a little weary to make modifications. He suggested getting in contact with a current tuliviki rep and seeing if the manufacturer recommends installing a flue damper. This could potentially clear all parties of insurance issues if something were to happen in the future. The plan would be to install an insert and modify it to fit the current design. His other(scary) alternative is to rebuild the entire chimney.

I was able to contact the original builder. He is now retired, but suggested that we can just close up the flue damper. The unit will not retain heat as well as it currently does, but could simplify the fix. I did a little digging and that some European countries do not allow for flue interruptions, and masonry units are built without this feature. I'm not a huge fan of this, but could be the only way to prevent a huge expense and construction project.

Thoughts would be very appreciated!
Cheers,
Jimmy

 

[begreen]

A friend has a Tulikivi. AFAIK it has no damper. Calling the US factory rep would be a good start.

Dealers - Tulikivi

The map service will help you find a Tulikivi dealer.

tulikivi.com

 

[EbS-P]

Most pressing is the failed clay liner. Do you suspect a chimney fire? How tall is the chimney and what size the clay liner? Is there an accessible cleanout? Does it meet 2” clearance to combustibles code?

The damper is just one piece that shouldn’t be a showstopper.

 

[John Lehet]

I had a Tulikivi from 1986 to 1998. Built it myself and loved it. I also had a full closure damper, which was in a terracotta flu next to the stove (but not in the wall. Concrete blocks with soapstone tiles. Seems to me the full closure damper is really important to keeping the heat, though I can understand the concern. I only burned poplar in it, which doesn’t coal really at all. Fire went out, damper closed. I imagine if you had a firebox full of coals and closed the damper fully, that would be very bad.

 

[John Lehet]

Maybe if you detroyed the wall the contains the chimney/damper, rebuilt the chimney it would be OK?. My soapstone tiled concrete blocks looked great.

 

[jfgros01]

Most pressing is the failed clay liner. Do you suspect a chimney fire? How tall is the chimney and what size the clay liner? Is there an accessible cleanout? Does it meet 2” clearance to combustibles code?

The damper is just one piece that shouldn’t be a showstopper.

No, don't suspect a chimney fire, but it doesn't meet the 2" clearance in the attic space. Chimney is a two story. We have a sister unit in the basement that we do not burn. Two 12" flues- same damper setup in the basement. We close the flue damper once it has burned completely out- my understanding is that it helps the unit retain heat.

 

[jfgros01]

I had a Tulikivi from 1986 to 1998. Built it myself and loved it. I also had a full closure damper, which was in a terracotta flu next to the stove (but not in the wall. Concrete blocks with soapstone tiles. Seems to me the full closure damper is really important to keeping the heat, though I can understand the concern. I only burned poplar in it, which doesn’t coal really at all. Fire went out, damper closed. I imagine if you had a firebox full of coals and closed the damper fully, that would be very bad.

We wait for a complete burn before closing the damper. Occasionally we close it a bit early if we can't fully wait it out. We have an excess of CO alarms around the unit and in the attic. They have never been tripped.

 

[jfgros01]

Maybe if you detroyed the wall the contains the chimney/damper, rebuilt the chimney it would be OK?. My soapstone tiled concrete blocks looked great.

This is an option, but a very expensive one. We were quoted about - 55k for the chimney rebuild. We also heat with propane. I'm going to see how much more propane we use this winter! Might not make sense financially.

 

[Todd]

Yeah the damper is there to keep the heat from escaping up the chimney after the fire is completely out as well as keeping the cold air from falling down the chimney. I can see why it could be a carbon monoxide danger if it was shut while still having coals.

Looks like you may have to do some demolition to where this heater connects to the chimney and see if it can be relined. Probably takes a 7 or 8” diameter flue size. I would do whatever it takes to make this safe and operational. Great looking heater, I’m jealous!

 

[John Lehet]

I’m jealous too, though the steady, low heat output is too low for this old house, perfect for my super insulated house I built it in. I think the output range is about 10 to 12k BTU/hour or so. I would burn 10 -24 pounds of wood to be released over 24 hours. Perfect for my small super insulated house.

Now I’ve got a small 1860s building. 10 pounds of wood doesn’t get me very far past the first cup of coffee, and it’s time to put a bunch more in and on through the day.

 

[John Lehet]

On mine, the concrete block chimney only went up — I can’t remember — either the height of the stove or up to the ceiling. From there up it was metal, I guess you call it Class A. I think concrete blocks up high enough to put in a damper and then class A the rest of the way would be much cheaper than $55k, though I understand you have the two stoves, two flues, which complicates that plan. Sell the basement stove? I guess the demolition of the existing chimney would add a lot to the cost.