My Insert is too BIG

[JayLii]

Hey everyone. I decided to start a new thread that better explains my problem with some updated photos for your feedback. Thank-you to @begreen who has been interacting thus far.

The main issue as you can see is the insert is too big and protrudes past my existing mortar fireplace. I am hoping to build out with steel studs and cement board to frame it in. I am planning on finishing the hearth and face with tile.

I will be adjusting the hearth size to accommodate for the extra space needed to get the 18" from insert to combustibles. Not excited about this, but I want to do this right. Side clearances are perfect with lots of play room for tile and side mantel. Top clearances are great only requiring 36.5" from hearth to mantel.

I will be filling in the space above the circulating chamber with roxul, sealing all joints with furance cement, covering top of chimney outside with flashing and cap, running a 6" liner to the insert.

My biggest problem is... it doesn't fit!!
What should I do?

PS. bonus question, should I still install a fixing plate/block off plate to the inside to seal the chimney as well as the circulating chamber? (still need to grind out the old damper)

 

[bholler]

I am not sure about Canadian code but in the us you would need 8" of solid masonry surrounding the insert so just build a new face for the fireplace out of 2 layers of brick or if you want to tile it just use solid 8" block and a concrete lintel.

 

[DBoon]

If the fireplace is just going to be used to hold the insert and not have a fire in it, why not remove the firebrick from the back and the side of the firebox and give yourself 3-4" more inches of depth and 6-8" more inches of width?

 

[JayLii]

If the fireplace is just going to be used to hold the insert and not have a fire in it, why not remove the firebrick from the back and the side of the firebox and give yourself 3-4" more inches of depth and 6-8" more inches of width?

I didn't even think of that. That's a good idea! What would I find behind the brick firebox? The brick chimney I guess right? That extra depth might even save me having to cut up the hardwood.

I've never done this before so my concern is what I would find behind it and any damage done to important adjacent bricks holding the chimney structure. Is this a normal practice?

Also, wouldn't this decrease efficiency losing heat out the back?

 

[bholler]

I didn't even think of that. That's a good idea! What would I find behind the brick firebox? The brick chimney I guess right? That extra depth might even save me having to cut up the hardwood.

I've never done this before so my concern is what I would find behind it and any damage done to important adjacent bricks holding the chimney structure. Is this a normal practice?

You can only do that if there is enough masonry behind there to maintain the required 8 inches. And you need to make sure the firebox is not supporting the smoke chamber.

 

[moresnow]

Was this the closest fitting model available? Seems like a rather major operation to make all these accommodations. Any chance there is a better fitting model at your dealer?

 

[JayLii]

I've started demoing the old brick firebox, I'll post some new pictures when that is done. @moresnow this was a special online order, they don't sell supreme fireplaces in Victoria at all. It was 6weeks waiting so I'm not waiting any more

 

[bholler]

I've started demoing the old brick firebox,

Have you confirmed that you have enough masonry surrounding that firebox to be able to remove it?

 

[JayLii]

Have you confirmed that you have enough masonry surrounding that firebox to be able to remove it?

I am having a WETT inspector come today to do a pre-installation inspection on the unit. I did take out the back of the firebox and there is more brick there which is I'm assuming attached or a part of the exterior chimney.

My concern now is the sides of the old mason firebox do not allow the circulating chamber to open wide enough. There are two blowers on this unit and they are designed to blow the air into the circulating chamber. The fans are located on the sides of the face and because the circulating chamber is closed in so narrow the fans are not aimed 100% in the chamber, more like 50%. But I don't think I can safely take out the sides of the firebox without compromising the integrity of the whole existing firebox.

This is getting complicated. I'm considering hiring some professional help to get me moving in the right direction. But the project is already more expensive than I thought it was going to be.

 

[bholler]

I am having a WETT inspector come today to do a pre-installation inspection on the unit. I did take out the back of the firebox and there is more brick there which is I'm assuming attached or a part of the exterior chimney.

So no you didnt?

 

[JayLii]

@bholler You were right. I ended up re-building the back of the firebox with refractionary mortar and firebrick. When I demo'd the old one it exposed the exterior chimney which was a nono. I'm still glad I demo-d it because I was able to refill some mortar lines as well as build straight up instead of on an angle inwards, giving me room for the liner to pass clear.

You'll see in the pictures I've built out the face with firebrick as well so the unit is completely surrounded by brick. I've also cut out the floor and have 18" from combustables on the front side.

My next question is: Can I tile directly on firebrick? It's a 3/8" marble honeycomb patterned sheet. Would polymer modified mortar be okay for this? I don't really want to cement board the face because that would push out the insert that much more. (1/2" durrock, 1/4" mortar, 3/8" tile...) Also trying to plan out the steel framing for that is pretty complicated. I just don't know how firebrick is for tile backing! I've asked in a tiling forum with no reply yet. This firebrick seems quite brittle and I think would be very challenging to anchor cement board to it without it splitting or cracking.

Getting pretty close to be ready to install the unit. Just planning out these last few details. I will be tiling the hearth with an arctic marble as well.

I've also opened up the circulating chamber as wide as possible and have a good portion of the blowers aimed inside of the box. The top of the box is now angled as well creating a natural draft to the louver. The nice thing about this circulating chamber is I don't need to install a fixing plate.

Thanks for the feedback,
James

 

[bholler]

You'll see in the pictures I've built out the face with firebrick as well so the unit is completely surrounded by brick. I've also cut out the floor and have 18" from combustables on the front side.

Good I am glad it is coming together for you

My next question is: Can I tile directly on firebrick? It's a 3/8" marble honeycomb patterned sheet. Would polymer modified mortar be okay for this? I don't really want to cement board the face because that would push out the insert that much more.

You should be able to yes