Removing Prefab Fireplace Help

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Joes2021

New Member
Dec 16, 2021
4
USA
Hi everyone,

I would like to do the demo and removal of an old prefab fireplace in order to replace with a high efficiency unit.

I can only remove from the front, so will be demolishing the tile facing and some drywall to pull the unit out.

My question is if I am unable to remove the screws connecting the firebox to the flue and decide to instead cut through the flue with a sawzall (going to replace everything anyway), is the weight of the flue supported by the firebox, or is it held in place along the chimney frame?

Also, either way, should I be able to remove the firebox without someone lifting the flue from the roof?

Would greatly appreciate any help!
 

Joes2021

New Member
Dec 16, 2021
4
USA
Forgot to add that I will be hiring a professional to install the high efficiency, and hopefully to remove the flue if I’m successful. I have a tall chimney and am hoping to be able to remove just the firebox without needing to use a ladder on the roof.
 

brianbishop

New Member
Sep 23, 2021
5
Bishop, California
Hi! I'm also new to these things, but I completed the demo/removal of my prefab fireplace just this past month.

I bet it greatly depends on the specific construction of your fireplace. I can only comment on mine, which I'll do in a sec. First, I want to suggest taking off the tile and drywall covering the framing, so you can look inside the wall. In my opinion, this is the only useful advice I'm giving (ha!).

Mine was installed around 1978. The connection between the fireplace and the pipe did seem to be the primary support but there was some support at the roof. I got most of the screws out and then muscled and pried the fireplace away from the pipe. At which point, the chimney pipe's storm collar was resting on the cone of flashing up on the roof. I later separated the chimney pieces inside my home as best I could, then went up on the roof and lifted the rest out; there wasn't a system of fasteners to hold it in place.

So was that storm collar to flashing bearing connection the primary support or not? I actually don't know. I don't think so. If it hadn't been there or hadn't been strong enough, the chimney would have fallen the extra few feet to the subfloor, I'm sure of that. Removing the fasteners at the fireplace then going up on the roof would have been safer.
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,868
South Puget Sound, WA
Typically, the weight of the chimney is supported by the fireplace. The exception would be if there was an offset in the chase that was strapped for support. With full front access, the anchoring screws should be accessible. Pull the chimney first and cover up the hole of the entire chase top with a tarp. With that out of the way you can focus on the fireplace removal.
 

Joes2021

New Member
Dec 16, 2021
4
USA
Thank you for both of your replies!

I understand it may be wiser to remove the chimney from the roof, but I really want to avoid that given how tall the chase is. My plan is to let it fall and cover inside, and then have a professional finish removing the chimney and installing a new fireplace.

So I am okay letting the flue fall to the floor if needed. My main question is whether it will even be possible to remove the firebox once disconnected from the flue, or if the weight of the flue (if firebox is only support) will make it impossible to pull the firebox out.

I want to demo the tile and remove just the firebox just to save a little on cost, and leave the rest to a pro.
 

Brawndo71

New Member
Nov 21, 2021
36
MO
I am far from starting this exact project, and like to read about it. My chimney is tarped right now, i may put a piece of galvanized steel cover over the metal surround, as it may be a year or two before i can afford this. It was letting in some water. Not using the fireplace until new one installed. I didn't like the connection of the chimney extension pipe to the cap, wasn't completely encased by the outer air cooled liner. Old ZC Heatilator. Not that it put out much heat anyways. I would have a professional do the installation. Looking at Valcourt/Osburn/ PE ZC fireplaces.
I don't have the SO's approval to be doing any demo this far in advance. It looks nice for now, maybe I'll just burn some candles in it.
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,868
South Puget Sound, WA
My plan is to let it fall and cover inside, and then have a professional finish removing the chimney and installing a new fireplace.
That probably won't work unless the chimney pokes up over 4 ft above the chase top. Even then it may get hung up on the storm collar. You would be better off temporarily strapping it in place to the nearby framing but it's going to be in the way of new work.
 

snobuilder

Feeling the Heat
Dec 16, 2021
432
WI
Your ZC pipe may actually be 2 or 3 separate pipes and the outer one will stay in place fastened up top at the chimney chase cap, while the inner pipe is mechanically fastened to the unit.