Engineering fireplace insert for builtin

[Seldom1883]

I've got a tricky situation. I was looking to replace my ventless gas fireplace with wood for this winter. I ended up ordering an Osburn matrix insert, at the time not not distinguishing zero clearance woodburning fireplaces and fireplace inserts.

When I removed the old ventless gas fireplace, it revealed a wood frame underneath which is in conflict with the requirements of matrix insert to have a masonry chimney.

Returning this unit for a refund is not an option at this point. So I want to see what my options are as far as engineering something within this space that would still be safe enough to operate.

As far as the chimney pipe goes, I am going to be using a triple wall duravent all the way through the roof to get that 2" clearance.

As far as preventing the wood around the insert from getting baked and catching on fire:
- Lining the entire inside of the builtin cavity with cement board along with rockwool insulation, making sure no wood is exposed inside
- Placing the insert on 2 sets of bricks covering it's entire footprint underneath
- Placing more rockwool batting to cover the subfloor of the builtin
- inserting a vent for airflow at the top of the cavity coming into the room to allow hot air to escape out of the built in
- using cement board to fill in the rest of the hole on the face of the builtin and finishing with the same rock
- any wood facing the insert would get insulation

Thoughts on this?

It's okay to say that this is a bad idea, but looking for a genuine discussion of solutions as well. I am not worried about inspections where i am. Thank you

 

[DAKSY]

Sorry, but I’d say you’re SOL. That insert is designed for a masonry or stone fireplace. Nothing you can fabricate will be even be remotely close to SAFE.

 

[begreen]

Yes, that's a no-go from the start.

 

[EbS-P]

Your solutions are sell the Matrix at a loss. This time of year I bet it would sell $500 below msrp. You lose 500$. Or build a code compliant masonry chimney I’d be shocked if it could be done for less than $8k. I freed standing would stove would be cheaper. Live and learn. Don’t cut corners with fire inside you home.

 

[Seldom1883]

Guess I'll have to go with a zero-clearance then. Any good suggestions of builtin inserts around the 4-5k price range? I am eyeing the stratford right now.

 

[EbS-P]

Guess I'll have to go with a zero-clearance then. Any good suggestions of builtin inserts around the 4-5k price range? I am eyeing the stratford right now.

While you are still thinking search the forum for what others have done when they replaced a zero clearance with a wood stove.

Is your budget for the whole project or just the ZC unit

 

[Seldom1883]

While you are still thinking search the forum for what others have done when they replaced a zero clearance with a wood stove.

Is your budget for the whole project or just the ZC unit

Just the ZC unit.

 

[begreen]

I can understand the mistake. Sales people and some stores use the term "insert" for ZC fireplaces. An insert, is not the same. It goes into a fireplace instead.
Also look at Valcourt and Ventis fireplaces. They are siblings of the Osburn.

How large of a unit are you considering? How large of an area will it be heating or will it be more for ambience burning than heating?

 

[Seldom1883]

I can understand the mistake. Sales people and some stores use the term "insert" for ZC fireplaces. An insert, is not the same. It goes into a fireplace instead.
Also look at Valcourt and Ventis fireplaces. They are siblings of the Osburn.

How large of a unit are you considering? How large of an area will it be heating or will it be more for ambience burning than heating?

About 2000sqft of the lower portion of my house.

I ended up ordering the stratford II today.

One question I have about the chimney pipe setup. I already have 15ft of triple wall duravent. Are any of these ZCs compatible with triple wall pipes? The manual for the stratford only mentions double wall pipes. Wondering if adapters exist to go from ZC to a triple wall immediately.

 

[Seldom1883]

Never mind, it does list duravent triple wall in the manual, wondering which adapter I need though. The sales person I ordered this unit from wasn't very helpful.



is the 6DT-AP anchor plate compatible with triple wall or is it double wall only?

Edit: I think this is it: (broken link removed)