Insert for Thulman l36

[Nosetotail]

Hi guys. I have a prefab fireplace that is about 30 years old. Its a Majestic Thulman L36. I would like to replace it with an insert however I have been told by a chimney sweep over the phone that the floor of the fireplace won't be able to support the weight of an insert. I live in a wood frame house and I have a hearth that is about a foot or so high and about a foot or so deep. It is a brick veneer front with prefabbed metal chimney that I can see going up through the attack. Looking down from the opening in the attack floor where the chimney comes through, I can also see the top and perhaps some of the sides of the fireplace where it starts to taper to the size of the chimney. The back of the fireplace backs up to a drywall wall in my daughters room behind the fireplace and there are closets on both sides.

As best as I can gather from the sweep, the fireplace sits on top of a wood frame that will have trouble supporting the weight of an insert. Can anyone give me an idea of what I can do to make an insert work, or what I will have to do and a shot in the dark ballpark figure on how much this work may cost. I initially thought it would be a piece of cake. The flue opening and chimney are large enough to accept an insert chimney liner, but now I am afraid I will have to cut the old fireplace out and perhaps bust up my hearth, but I really don't know what I'm talking about.

 

[mellow]

Kudos to that sweep! He knows his stuff and isn't trying to make a sale.

Do a search for Alcove installs or ZC rip out, most rip out the ZC fireplace and install a freestanding stove in its place.

You could install another ZC fireplace that would be more efficient as well.

 

[bholler]

I agree with mellow. I looked at the instructions for your unit and it does not say that you cant put an insert in it. But it is 30 years old. The life expectancy of this type of unit is about 20 years. I would not put an insert in there either if i was asked to do the job.

 

[Nosetotail]

Kudos to that sweep! He knows his stuff and isn't trying to make a sale

I didn't think he was. He just said it was a bad idea, and then said he would not put an insert in to my fireplace. I respect that.

As to a freestanding, that would be a hard sale to my wife. I already had a hard enough time convincing her that we should get an insert, let alone an outright stove.

 

[Nosetotail]

So I just looked at the fireplace from up in the attack, and it seems it is sitting atop stacked masonry blocks. Would that be solid enough to support the weight of an insert? Supposing it was, what are some other considerations I need to look at. I would install a liner in the existing flue pipe if that is a concern.

 

[begreen]

It's the metal floor of the old fireplace that is the weak point. It is not designed to support the weight of an insert. A good insert is going to cost ~$2500-3000 and that is before adding a stainless liner. Instead, consider replacing the current Thulman with a Flame Monaco ZC fireplace, or similar lower cost unit.
http://www.efireplacestore.com/cpf-93375.html

 

[Nosetotail]

Ok. I do understand that. I'm just trying to do this without too much intrusion into my house. Both sides of the fireplace have a closet with the really thin veneer wall. That would be easy access, however there is a stud in the way that I might have to cut out. I don't want to come in from the back as it would require refinishing an entire bedroom as it is wall papered and I doubt I can find matching wall paper.

As to either closet, there is not enough room to slide a new ZC in, unless this can be done from the front. I could cut out the old ZC from the sides and then open the front a little if that would work.

On that same note, I could access from the sides and shore up the bottom. I already understood that the floor may not be able to support an insert, but I figured as long as I have it shored in the right spots that it would be sufficient. Also, I had an idea to line the bottom of the old fireplace with a 1/4" steel plate or thicker if necessary.

Then there is the replacing of the flue pipe and what that would entail.

I admit I don't know how my fireplace is built and I didn't consider that it could have a double floor and that shoring from the bottom would not help.

As to a modern ZC fireplace, how do these compare to inserts or stoves for efficiency and heat output?

 

[begreen]

There is a very big difference. Modern EPA fireplaces vary, just like stoves, but a decent model can put out a significant amount of heat efficiently and cleanly as long as the wood is fully seasoned.

 

[Nosetotail]

If I did replace with a modern ZC fireplace, is there any chance I can stick with the old prefab flue pipe? The sweep we used to inspect it this season, said it was pretty much clean, and that was after we used it quite often last season?

What is a general ball park figure for replacing the flue? I don't think I have a brick chimney stack on top. It looks like immitation brick siding if that makes any sense.

 

[mellow]

I wouldn't, it has gone past its life expectancy at 30 years old, I would go with everything new.

 

[begreen]

If I did replace with a modern ZC fireplace, is there any chance I can stick with the old prefab flue pipe? The sweep we used to inspect it this season, said it was pretty much clean, and that was after we used it quite often last season?

What is a general ball park figure for replacing the flue? I don't think I have a brick chimney stack on top. It looks like immitation brick siding if that makes any sense.

Unlikely. The old chimney is probably air cooled. New EPA units usually require class A chimney. Additional cost of the chimney will depend on the height and hassle to replace. Some chases are large enough to work in, but others not. The pipe itself could be 700 to a thousand or more.

 

[Nosetotail]

I read some of the Q&A on the Flame Monaco LTD and it made mention of venting with a 6" SS flex in an existing masonry chimney that is in good condition. Could I just get away with pulling in a new liner?

 

[begreen]

From the description it sounds like this is not a true masonry chimney. If not, no a liner is not sufficient. Ask your sweep if they know what pipe is in place currently.

 

[Nosetotail]

I'm not sure. I would have to get on the roof. It has a brick design but it is solid white and appears to be perfectly uniform like something prefabbed. Perhaps it is made of ceramic panels or something. The flue is just a multi walled round metal pipe.

 

[begreen]

If you are trying to save money then an option might be to put a free-standing, rear vented stove in front of the fireplace on the hearth. How well that would work out depends on the hearth setup and lintel height. If all is good for this type installation then a liner could be run up the chimney to connect the stove.

 

[Nosetotail]

If I had my druthers, that is what I would do. However my wife thinks even the best looking insert looks archaic. I live in Florida so my goal is to maintain some resemblance of a traditional fireplace and to turn it into a better than zero sum gain in energy efficiency, not to mention, the bonus of cutting down on the actual amount of wood I use to get the heat.

I don't need the highest output unit, just one that is going to be a plus. I do like the ZC option. However, my other goal is to be as minimally invasive as possible and to be able to do as much of the labor as I can before I call in a pro to do the work that I am not qualified to do.