Advice on pending Jotul F45 Greenville Alcove Installation

[rowanoverland]

We took out an old non-venting propane fireplace to be replaced with a Jotul F45 Greenville. I have a professional installing the stove itself, but I'm building out the alcove myself to receive the stove later this month.

I'm hoping for some input and validation on my ideas on this installation.

I've done the demolition as shown.

I'm planning on replacing the old insulation with new rockwool batts, lining the alcove with durock against the 2x4s on the sides and back, and installing a 2nd layer of durock on the back with 1" ceramic spacers and an opening/gap top and bottom on that back durock/tile board for air flow/heat shield. The entire alcove will have 12"x12" slate tiles, leaving of course the openings on the back wall for the heat shield. The hearth will use 8" cinder blocks (to raise it up from floor level for appearance and easier loading) and durock with slate tile.

I believe with this 2nd layer of durock on the back, spacers, air space, and tiles, we should be able to install the stove 7" in front of the tile on the back wall. My width on the alcove, from combustible 2x4s, is about 52", so I think we're good on the width with not having to have heat shields on the sides.

Does this sound like it meets the spec for heat shielding to reduce stove spacing to the back wall?

If I have the cinder blocks/durock/tile on the heath under the stove, do I need a bottom layer of durock below the cinder blocks also (between the wooden floor and the block)?

I am planning on installing an outside air feed through the hearth also… Pretty sure that has no bearing on the clearances questions.

This manual is what I'm relying on for my dimensions to combustibles. https://www.jotul.com/sites/usa/files/products/139967_Rev C_Manual_F 45 V2 - ENG (shrunk).pdf

Having not done this before, please share your wisdom with me!

Thank you.

 

[begreen]

If there is 52" between the side stud walls, then the additional wall protection is superfluous and not required. Jotul calls for a minimum of 50.25" alcove width. Based on the description it would be ok to just put up the durock and tile it. This stove only needs ember protection for the hearth so no need for the cinder blocks. Screw the 1/2" durock down as recommended and then tile.

 

[rowanoverland]

Thanks. The extra layer of durock with air gap would only be on the back wall, not the sides, so we can reduce the spacing to 7" on the back wall.

 

[begreen]

Gotcha. There is no need for the additional durock layer behind the shield. Just be sure that it is on the spacers and starts an inch or two above the finished hearth floor, and is open at the top by an inch so that air can freely convect behind it. One trick to make spacers is to cut 3" x 5' strips from a sheet of 1/2" durock, then screw them doubled up on the studs vertically to create the 1" air gap.

 

[rowanoverland]

One quick follow-up... is the 7" back spacing to the combustibles or the heat shield? If the combustible than I'm really looking at 5" space between the tile face and the back of the stove, right?

1" of air space, 1" of durock and tile...