Wood Insert & Hearth Size Problem

[soundog]

We have an existing fireplace and want to put in an efficient wood-burning insert. Local (Washington state) code requires 16" of hearth in front of the fireplace opening, and that's exactly what the builder put in (using stone). The fireplace is flush with the floor (see photos). The flooring in front of the stone hearth is 3/8" ceramic tile on 1/2" gypsum board (all on plywood). The gold fireplace doors shown are 44" wide x 33" high.

Reading through various stove insert manuals, it appears that, by the time I put in the insert, I will exceed the required hearth distance in the front of the stove. For example, one requires "16 inches in front of the fan housing", another (flush mount) requires 17-7/16" in front of the insert's door. T he black tile area in front of the stone hearth is a traffic area, so I can't build up there.

Is there an existing insert that might work in this situation, or is there a low-cost solution anyone can think of?

 

[begreen]

The distance for the hearth is measured from the stove door. Looks like a flush insert will be required. The two side side walls may make fitting a surround a bit challenging.

 

[soundog]

Thanks, begreen. The current fireplace door/screen assembly is 44" wide, and it there are inserts with surrounds that would fit. My main concern is the hearth distance in front, since its only 16" flush to the fireplace opening.

Update: I'm reading a lot of insert manual pdf's online. So far, the only insert I've found that is completely flush with the opening is the Osburn Matrix. Its spec reads "air jacket flush with fireplace opening" and states my 16" hearth would be OK in the U.S.

If anyone knows of other inserts that would work (completely flush with 0"" added projection), please let me know. We're looking for medium output, supplemental heat that won't drive us out of the living room.

 

[electrathon]

Can he claim the tiles on the room floor as protection?

 

[bcrtops]

Can he claim the tiles on the room floor as protection?

Why not? As long as the grout is non-combustible as well & no "R" value required for the hearth.

 

[bholler]

Can he claim the tiles on the room floor as protection?

Yes as long as the protection required is only ember protection and those are actually ceramic tile.

 

[soundog]

Yes, the tiles are actual ceramic.

 

[electrathon]

That should lengthen your list from few to many.

 

[bholler]

Yes, the tiles are actual ceramic.

Then you are fine as long as the insert only needs ember protection. What is under that tile btw?

 

[soundog]

1/2" cement board (or gypsum?) is under the tile, house built in the 70's.

I just looked at specs for an Osburn 2299 (the insert that I'm interested in). They say that for fireplace openings over 6 sq ft that you need 20" of hearth extension (or 16" for less than 6 sq ft opening). Well, our hearth extension is 16", but our opening is about 8 sq ft!! So I'm assuming either the code changed since the house was built, or it wasn't built to code. [correction: Osburn 2200!]

Where does that leave me when it comes to installing an insert??

 

[OhioBurner©]

Hmm, the Jotul Rockland I had was flush and needed only 16" from the door opening not the actual door that is another inch or two thick. I thin that is pretty standard. I see it needs an R-value hearth of .5 minimum though under the Canadian description for 18" but I see no mention of R-value otherwise.

(broken link removed to http://jotul.com/us/products/wood-fireplace-inserts/_attachment/40021?_download=true&_ts=15578b74d93)

The Rockland was a nice unit but couldn't quite keep up with this drafty poorly insulated place. Freestanding stove was much more efficient. But if it suffices for your heating needs then it is a nice stove.

Those sides of your fireplace that come outward might make it a bit awkward to load though.

Several inserts need only 'ember protection' as long as your tiling and grout are continous with no gaps where embers could get to cumbustible material than you could probably count your floor in front of your hearth. Blaze King Princess insert?

 

[weatherguy]

How big an area are you heating? Is this just going to be supplemental heat?

 

[soundog]

Good info, all ... this is very helpful.

@ohioburner .... I like that Rockland stove, and the specs look like they would work nicely for my situation. (The Blaze King looks like too much of a stove for our needs.) FYI, the existing stone sides are 4' apart, so that would still work, even if cumbersome. Also, the tile/grout is continuous....and it continues out 29" from the front of that 16" stone hearth.

@weatherguy ... I'm thinking more for supplemental (to a heat pump), and so we can enjoy the fireplace without wasting wood and energy. It doesn't get bitter cold here, plus the insert will be in the living room where we hang out, so I don't want something that would drive us out.

 

[OhioBurner©]

Most inserts need power for blowers too, so keep in mind you'll have to have power there and maybe a cord exposed up and over those sides there. In regards to the Princess insert, I am not personally familiar with them but if they follow suite with the rest of BK stoves they can idle down much lower than a tube stove like the Jotul Rockland I mentioned, so it wouldn't be too much stove as far as heat is concerned, it'll go lower than the Rockland. It's more effecient but not as attractive though, and if this is just some supplemental heat then it might not be as big of a deal to you, either will be far more efficient than an open fireplace.

 

[soundog]

Thanks for the great input so far. I'm still looking for inserts to consider, after reading many user manuals and specs.

To summarize, the insert will be flush with the floor, the brick hearth extends 16" and then I only have a total R value of 0.215 for my hearth extension (3/8" ceramic tile + 1/2" cement board non combustible stuff), so there's not enough to enough to meet inserts with R requirements. Sounds like I need something that is flush mount and only requires ember protection in front of the stove.

The insert will be in our living room/TV room, so we want something that will make our fireplace efficient for supplemental heat when enjoying a fire, but that won't drive us out of the room. (Our ceiling slopes to 17' high at the fireplace, and we use fans.)

Any other suggestions for inserts to consider?

 

[weatherguy]

Morso has a flush insert, I think they're pricey though.

 

[begreen]

1/2" cement board (or gypsum?) is under the tile, house built in the 70's.

I just looked at specs for an Osburn 2299 (the insert that I'm interested in). They say that for fireplace openings over 6 sq ft that you need 20" of hearth extension (or 16" for less than 6 sq ft opening). Well, our hearth extension is 16", but our opening is about 8 sq ft!! So I'm assuming either the code changed since the house was built, or it wasn't built to code.

Where does that leave me when it comes to installing an insert??

Osburn 2299? Is that a typo? Osburn 2200 insert? Looking for where this info came from. Haven't found it in the 2015 Osburn 2200 insert manual. May not even be relevant as the black tile is your hearth extension. However, you are correct about the R-value. It needs to be R=1.0 for this insert with a flush hearth.

FWIW I'm surprised that hearth passed inspection or code review if only a single layer of gypsum board is underneath the stone. One workaround might be to install a freestanding, rear-vent stove there, that has an ember protection only hearth requirement. The deciding factor there might be the lintel height.

 

[soundog]

Thanks for your help, @begreen. Well, there may be more backer board under that stone and/or tile .... I just don't know of a way to look and see, or find out.

Yes, that's a typo ... I meant the Osburn 2200. It has a bay window so requires a bit more up front for hearth extension.

Right now I'm looking at Travis Industry's "Medium Flush Wood Plus" inserts, which seem to be branded as either Fireplace X, Avalon, or Lopi. They are flush mounted, and are spec'ed for just a 16" hearth (which is the depth of my existing flagstone hearth shown in photo, in front of the black tile). Those are looking promising....

 

[rwhite]

Good info, all ... this is very helpful.

@ohioburner .... I like that Rockland stove, and the specs look like they would work nicely for my situation. (The Blaze King looks like too much of a stove for our needs.) FYI, the existing stone sides are 4' apart, so that would still work, even if cumbersome. Also, the tile/grout is continuous....and it continues out 29" from the front of that 16" stone hearth.

@weatherguy ... I'm thinking more for supplemental (to a heat pump), and so we can enjoy the fireplace without wasting wood and energy. It doesn't get bitter cold here, plus the insert will be in the living room where we hang out, so I don't want something that would drive us out.

If it extends out 29" and you find a stove only needing ember protection you have 45" to play with.

 

[seabert]

I am not sure if I understand the problem with this install. My VC Montpelier has a front that is basically flush. However the issue I see is with the insert height and width so that it looks right and fits between those 2 brick walls coming out. A surround may address that problem. An insert with a fan needs a place for the cord so that may be another issue(pointed out earlier in this thread).

 

[soundog]

@seabert, in a nutshell the problem is meeting code per the specs for the insert. My fireplace is floor level, with a 16" hearth, and only ember protection beyond that. The Montpelier stove requirements are shown below, but there is a typo in the chart — in the U.S. only 16" is required for "A". Nice looking insert; I'll add it to my consideration set!

 

[rwhite]

@seabert, in a nutshell the problem is meeting code per the specs for the insert. My fireplace is floor level, with a 16" hearth, and only ember protection beyond that. The Montpelier stove requirements are shown below, but there is a typo in the chart — in the U.S. only 16" is required for "A". Nice looking insert; I'll add it to my consideration set!

View attachment 191968

I don't know Washington code but what makes the tile any different then the "hearth"? Just because you transition to a different material or color doesn't change that it's all noncombustible. If a stove requires a certain r-value that's one thing but tile vs brick vs stone or for that matter you can just throw a piece of durock on the floor and meet non-combustible ember protection.

 

[rwhite]

Whats under the stone? It may have no more r-value than the tile.

 

[rwhite]

@seabert, in a nutshell the problem is meeting code per the specs for the insert. My fireplace is floor level, with a 16" hearth, and only ember protection beyond that. The Montpelier stove requirements are shown below, but there is a typo in the chart — in the U.S. only 16" is required for "A". Nice looking insert; I'll add it to my consideration set!

View attachment 191968

I don't think the chart has a typo. It is 18" unless you elevate the insert 3 ".

 

[soundog]

rwhite -- if you read the same insert's manual, it specifies 16" in the body of text for required hearth frontage in the U.S. (16" is typical in U.S. specs vs 18" in Canada), which conflicts with the chart. Whatever, that insert won't work for me because the surrounds are too small. BTW, I'm covered for R and k requirements on the hearth, thanks, so no worries there!