Stüv cube install - question regarding insulation under stove

[rasputin]

I'm looking to get stüv-cube stove (yes stove, not insert) installed inside my fireplace - https://stuvamerica.com/en/ca/products/stuv-16

Probably the 16-68 as the 16-78 might not be sold in the US.

Anyway, contacted a dealer and they said everything looks good except for one thing - they're worried about the wooden beams that go underneath the hearth in front of the fireplace. They're worried that the heat would eventually char them. They propose a 4" insulating platform for the stove. I'm not crazy about the idea because there isn't much clearance. Yes, I'm being picky.

They mentioned that the alternative would be building a new hearth with proper insulation beneath it. I'm not interested in doing that because it matches stone flooring we have in our entryway. Its an older home.

Pics above and below -

First pic shows cardboard mockup of stuv-cube 16-78. the 16-68 would be 2" narrower on each side. The second pic shows the construction of the floor underneath the hearth.

I know I'm likely to just go with the platform - but are there other options? Has anyone else had to deal with this?

Thanks

 

[SpaceBus]

Looks like a handsome stove, but this stove offers nothing in the way of output adjustment other than load size. I would perhaps look at this stove as a design piece for ambiance, but not really for primary heat for the home. I also chuckled at the promotional photo seemingly showing a blazing fire in the middle of summer. The clearances for this stove state 48" clearance to combustibles to the front and a non combustible (but not insulated) material in 16" in front of the glass and 6" on either side of the glass.

What are the dimensions of the hearth and fireplace you already have?

 

[kennyp2339]

With no air control you're essentially "free burning" and relying on your draft to effectively control the fire, drafts sometimes are pesky, in warmer weather they can slow, in very cold weather they can speed things up, I know with my setup I need to have a stove that I can control, but also a damper to reduce flow since I have a high draft, I couldn't imagine what a stove with no air control would be like.

 

[begreen]

Another option would be to go with a different stove that needs ember protection only for the hearth.

 

[rasputin]

You're correct, we're getting it for ambiance - our gas burning furnace works quite well.

The firebox is 48" wide, 20" deep, and the arch ranges from 24" to 36" tall. The hearth extends 18".

I think this is the diagram informing the platform recommendation -
quoting the installer - `One way would be to demo the existing hearth and install a new hearth stone that has mineral fiber board underneath it which is a product that is commonly used to alleviate thermal implications.`

I wonder if this is all trouble caused by the fact that the stove doesn't have legs.

There's part of me thats entertaining the idea of insulating the hearth from below or removing the hearth and then insulating beneath it. But there must be numerous details I'm overlooking.

 

[SpaceBus]

If I'm reading the manual right, you shouldn't need anything beyond the hearth of your current fireplace. Begreen will know more than me about your hearth requirements based on the manual. What is your plan for the flue? Are you considering any other stoves? There are a few I would suggest instead of this one.

 

[begreen]

The original hearth is improper and the installer's suggestion doesn't make it more proper. If the house is sold and someone goes back to using the fireplace the hearth will not be code legal. That could end up being a liability issue.

A hearth pad that meets the mfg. spec is what is required. Might as well get or make one that extends under the stove from the back to at least 16" in front of the stove door. Or get a stove with easier hearth requirements.

 

[rasputin]

What is your plan for the flue? Are you considering any other stoves? There are a few I would suggest instead of this one.

Uh, I'm not sure what flue options I might consider. I'm open to recommendations

A hearth pad that meets the mfg. spec is what is required.

Where is that specified? I likely looked right at it but didn't understand. I'd like to understand the specs.

 

[begreen]

Uh, I'm not sure what flue options I might consider. I'm open to recommendations



Where is that specified? I likely looked right at it but didn't understand. I'd like to understand the specs.

The hearth is supposed to be one continuous unit from the back of the fireplace to the front edge of the hearth with no combustibles underneath. This is our local code, which is essentially the national residential code plus some earthquake structural requirements:

 

[rasputin]

The hearth is supposed to be one continuous unit from the back of the fireplace to the front edge of the hearth with no combustibles underneath.

This would be true no matter what we installed. The house was built in 1927.

 

[SpaceBus]

Perhaps an attractive pad could be made that extends from the back of the inside of the fireplace out as far as needed for the appropriate protection.

 

[Simonkenton]

Rasputin: I loved your work with the Czarina. It is unreal how you saved the life of that little prince.
I still say you got a raw deal on your last day there in the palace.

 

[begreen]

I still say you got a raw deal on your last day there in the palace.

It was a pretty epic last act.