Help me with ideas for my hearth build

[Gettysburg150]

Hello all,

Another newer member here. Been enjoying using wood to heat my home since its way more affordable than heating oil.

With the constant desire to make sure my wife is warm, we are adding a insulated chimney to hook up one of our two wood stoves. Currently we have a Harman CW30 in the basement that isn't doing too much to heat the house and a Fisher Goldilocks wood stove in the garage that we haven't burned yet.

We are still undecided which stove to use. I like the 4 flat surfaces of the Fisher that could possibly be used for cooking in an emergency, but the Harman does have a blower on it which seems to move some pretty decent heat once its up to operating temperature.

So first question, which stove would you use?

Next, I wish to build my own heart/surround for the wood stove. I still need to find the clearances for the Harman (which are on the back, haven't been able to find an owners manual yet but I know there's info back there, its just too close to a brick wall in the basement currently to read it) but the clearances for the Fisher are 18". Im figuring the Harman shouldn't be any further than that.

I was hoping to find a veneer brick to match the chimney that goes through the kitchen (which is where the stove will be). The current kitchen is an addition on an exterior wall of the house. On this exterior wall there is the original brick chimney that comes up the middle wall and is exposed. This is used for venting an oil fed hydronic boiler.

There are 2 power outlets near the corner where we are going to place the wood stove. They're over 18" from the direct corner.

I have read a couple of DIY builds, but still unsure what I can do to be safe and attractive while blending in with our décor.

For the base can I build it up with 2x4's, put down cement board, then put a brick veneer over it and be safe?

If we use the Fisher it is supposed to be off the floor a min of 1", can I just put regular bricks at each corner to raise it up, having it still sitting on the 2x4 base?

Should I have a 1" space still between the wall and the surround that I would like to build? I'd like to go about half way up the wall with a brick veneer. Thinking of gluing the cement board to the current wall then laying the veneer on top of that. I think the air space is going to make it a bit complicated due to the electrical outlets.

Is there a specific distance I need to stay away from the outlets? If we use the Harman I'm going to need power for he blower. If I was to glue the cement board directly to the wall I was thinking of just cutting out where the outlet is and blending it in by maybe splitting down the veneer and then the outlets would be slightly recessed. An air gap would be better for clearance but it seems to me would make it difficult to still get access to power without cutting a hole.

If we spaced it out an inch and cut a hole at the power outlets to gain access would that ruin the air gap?

We did have a quote on zero clearance installation with them doing all the install and supplying the board and hardware. It effectively doubled the price. I was told the stove board was going to cost me @ $500 each and I'd need at least 3 of them. I know I can do the stove board way cheaper by myself but I think a brick veneer would flow a lot nicer.

Thanks in advance!
Jason

 

[Oldman47]

A few observations.
When talking about the Fisher you talk about using it for emergencies but the other stove needs power. First things first. Decide what you want the stove to do for you. If you want a stove for emergencies, don't use one that requires any power.
If you already have a hydronic connected to a chimney, you can't add another wood burning appliance to that chimney without creating problems.
Brick itself is not combustible but without that vented 1 inch air space it does nothing to reduce allowed distances to the combustibles behind it.
I have no idea on the height of that Fisher. Does it have a standard base that it mounts on? No 2x4 adds anything at all in terms of distance to combustibles or hearth R values. No matter what else you do, the hearth must meet manufacturer's specifications and its structure needs to be strong enough to hold up the stove and the fire barrier part of the hearth. I use dimensional lumber to do lots of things with no problem at all but when it comes to a hearth I also need to follow the manufacturer's recommendations. That means that anything you build needs to have the recommended heat protection on top. I am in the process of installing a new wood stove that only requires ember protection so tomorrow I expect to install some nice looking 3/8 inch thick tile in a bed of thin set on top of my layer of 1/4 inch thick Durock. So called ember protection means that if sparks or worse yet logs fall out of the stove, it won't cause a fire because what you have there can't burn easily. There is no specified R value that I can find that it needs to meet
Check the literature on the stove you are installing. A 1/4 inch layer like I am installing has almost zero R value and about half of the stoves out there do require some minimal insulating value. Unless you are installing an ember only stove, it will take more than a layer of cement board and tile to get you there.

Note: Installation requirements and owner's manuals are often available on line. Go get some for your stoves.

 

[Gettysburg150]

Thank you oldman47

The Harman will still throw heat but not as effectively without the blower. Even in an emergency I think it will suffice but not as well for say cooking purposes as the Fisher, though either way I can adapt, overcome, and improvise.

Thank you for the point on the hydronic flue, I do realize this and am having a seperate flue installed.

I also figured so much with the air gap/no air gap. No air gap I will still need 18" clearance from combustibles. But will having the brick directly against combustibles make the situation worse because the brick will get warm? Will it need to be 18" from the brick at that point or still 18" from the wall the brick is attached to?

The fisher does have a stand, I have the manual for this one. Only thing I need is 1" spacing under it so that air can enter for combustion, not for a clearance issue. For the base its just ember protection as well.

I have to call Harman on the CW30 manual, can't find the info anywhere. But it does have clearances on the rear data plate thankfully

 

[begreen]

Is this real brick? If so, and standard thickness, it's acceptable shielding and will earn a 33% clearance reduction to 12".

https://www.hearth.com/talk/wiki/nfpa-wall-clearance-reductions/

 

[Gettysburg150]

I was actually thinking brick veneer, at which point there probably won't be any clearance reduction I'm assuming

 

[begreen]

Correct.

 

[Gettysburg150]

Is there any worry about reinforcing the floor to support the weight of the stove? There is a crawl space underneath. The stove weight is about 545lbs

 

[begreen]

Probably not. The pad will spread the weight over several joists.

 

[Oldman47]

Is there any worry about reinforcing the floor to support the weight of the stove? There is a crawl space underneath. The stove weight is about 545lbs

Look at the floor design specs you have. Typical residential designs are for 20 to 30 PSF live load. The floor will not break if you exceed that value but it will tend to degrade over time. I am guessing that you are probably going to spread that load over 6 or more square feet but would be careful about an overload. If I had easy access to a crawl space I think I would reinforce the area around the hearth with one or more jacks under a nearby beam to help support the floor. I am installing my new stove over a main building structural member so it is a no brainer for me but if you are in the middle of a span you will want some reinforcement for the long term, not just the first year where it would probably be safe enough. (I am far more familiar with building structural strength than I am with wood burning.) If you are looking at 545 pounds of live load I would consult a structural engineer who could determine the actual situation that you have and could suggest what you need to do to compensate for that load. It beats having the building 10 years later with a half inch sag in the floor in that area.

 

[begreen]

The average hearth pad is more like 12 sq ft. Typical safe, residential live loads are 40 lbs/ sq ft.. If the stove is on an exterior wall, then my understanding is that the load carrying is even greater.

 

[Ashful]

I wish my floors only sagged 1/2". You should see my toddler try to negotiate our second floor hall, with what must be 1:12 slope to one side.

 

[begreen]

We have a 90 yr old house that has what must be close to 1000# of refrigerator and food in the kitchen. No sag there over 20+ yrs. No sag where our #600 stove sits and this is on joists roughly 24" centers.

 

[Gettysburg150]

I'm not sure what the joists are, I think 16 OC since it's a newer addition but I have to pull insulation panels down to verify

The stove placement will be in the corner of two exterior walls

I was thinking if building up the pad with 2x4s to make sure I have good weight distribution over several joists

Here is our rough lay out of placement

 

[Gettysburg150]

And I know, blah, carpet in the kitchen. We didnt do it, just bought it that way. But I'd rather be warm next winter than have a pretty floor to look at, since the dogs make a mess anyway.

We will be cutting the carpet from underneath when I build up the hearth

 

[begreen]

What stove is this for? I could be in error, but I thought the Fisher is unlisted and has 36" clearance requirement. Is there a tag on the back of the stove specifying a closer clearance? What are the CW30 clearance requirements on the stove label?

 

[Gettysburg150]

Fisher is a listed stove, Goldilocks model and is good at 18 or 16" clearance, can't recall right now. But we're going to use the Harman which is a 14" clearance. Called harman and they sent me the manual after I got them the serial number

 

[begreen]

Got it. 18" for a corner install and minimum 16 sq ft hearth.

 

[Gettysburg150]

Yeah thats the one lol

On the harman I only the ember protection 8" to the sides and back, 16" to the front. 14" from the corners on corner installation