Replacing Heatform with insert, and demo/remodeling stone

[Jeff15]

I have a Montlake 300 on order that I want to install into my 70s house that has a heat form (I'm pretty sure), along with demo'ing the existing green rock fascia and remodeling with something else. I need to have this installed for winter!

I started happily demo'ing the green rock above the firebox, then paused for fear of loading bearing concerns around the heat form. I understand most people just cut out the damper and the backside to make enough room for the liner, but since I'm remodeling the whole fireplace anyway, and I want to add things like electric (for the fan) and Auber flue temp sensor, I might as well rip it all out...

Some facts

• Mid 70s house in Douglas County, NV
• Masonry/brick (upstairs), large stone/rocks (downstairs), and cement blocks make up the chimney
• 4 flue chimney, with terra-cotta liners in each. Upstairs open fireplace (heat form) on one side, and small Morso stove (no liner) on other side. Downstairs open fireplace (heat form with a gas line - I've capped off the gas) on one side, outdoor BBQ/smoker insert on the other side
• 3" drop from the hearth into the firebox (b/c of gas line)

Rough goals / plan

• Demo all the downstairs green rock, keeping the upstairs brick, open fireplace, and small stove as-is
• Remove heat form, or cut out what is needed (leaning towards removal, to make electric outlet, Auber sensors, etc easier)
• Install Montlake 300 with insulated flexible dual wall liner, roxul, back off plate, etc
• Remodeling of fireplace will likely have to wait til next Spring/Summer

I'm pretty much ripping the house down to studs, adding a garage addition, renovating, etc, so I want to do this fireplace right.


Appreciate your advice.

 

[bholler]

I have a Montlake 300 on order that I want to install into my 70s house that has a heat form (I'm pretty sure), along with demo'ing the existing green rock fascia and remodeling with something else. I need to have this installed for winter!

I started happily demo'ing the green rock above the firebox, then paused for fear of loading bearing concerns around the heat form. I understand most people just cut out the damper and the backside to make enough room for the liner, but since I'm remodeling the whole fireplace anyway, and I want to add things like electric (for the fan) and Auber flue temp sensor, I might as well rip it all out...

Some facts

• Mid 70s house in Douglas County, NV
• Masonry/brick (upstairs), large stone/rocks (downstairs), and cement blocks make up the chimney
• 4 flue chimney, with terra-cotta liners in each. Upstairs open fireplace (heat form) on one side, and small Morso stove (no liner) on other side. Downstairs open fireplace (heat form with a gas line - I've capped off the gas) on one side, outdoor BBQ/smoker insert on the other side
• 3" drop from the hearth into the firebox (b/c of gas line)

Rough goals / plan

• Demo all the downstairs green rock, keeping the upstairs brick, open fireplace, and small stove as-is
• Remove heat form, or cut out what is needed (leaning towards removal, to make electric outlet, Auber sensors, etc easier)
• Install Montlake 300 with insulated flexible dual wall liner, roxul, back off plate, etc
• Remodeling of fireplace will likely have to wait til next Spring/Summer

I'm pretty much ripping the house down to studs, adding a garage addition, renovating, etc, so I want to do this fireplace right.


Appreciate your advice.

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There is absolutely no reason at all to remove the whole heat form. And even if you do there is no reason to demo the masonry

 

[Jeff15]

There is absolutely no reason at all to remove the whole heat form. And even if you do there is no reason to demo the masonry

OK, I understand not needing to remove the heat form, I will plasma cut out the needed areas.
The reason to demo the stonework is to remodel it to a different kind of rock... but I will just do what's necessary to install the new insert for now and consider the remodel next year.