New Jotul F400 installation questions

[Noah]

I think I'm doing pretty good so far but I need some feed back from the experts on a few things.

First is the hearth pad dimensions and clearances. The stove instructions say a minimum of 42"W x 44"D, I guess this assumes that the dimension behind the stove is at minimum clearance to combustibles right? The hearth pad I'm building is going to be larger than the minimum required so I should be fine as long as I keep to the clearances in the manuel that say that the hearth pad needs to extend a minimum of 8" on either side and 16" out the front. Doesn't NFPA 211 require 18" from the front or does the stove manuel take precedents? I think my hearth pad will be about 44"W x 48"D and butted to the wall in the back with the stove about 8" from the wall. Does this sound alright?

Next related question. The manuel says that there needs to be a minimum of 8" of non-combustible material that extends out the back of the stove but the minimum clearances to the wall are 7", I assume go with 8" to be safe? This brings me to my next question.

The chimney connection. My stove will have an outside wall behind it and I want to go directly out the rear of the stove through the wall and into the Tee. In reading the chimney manufactures (Simpson DuraTech) directions for installing a wall thimble it says that there must be a section of chimney that extends inside a minimum of 6" measured from the inside wall. I seem to remember reading somewhere (chimney manufactures FAQs) that the stove can not be connected directly to the chimney but needs to have a piece of connector pipe between the stove and the chimney. How can I connect the stove to the chimney and still be with in the clearances of 7" to 8" from the wall? Can I use a 2" piece of stove pipe? Is it even possible to install the stove and chimney in this configuration with the exhaust passing through the wall directly behind the stove?

Thanks,

Noah

 

[begreen]

I've never done a straight out installation, but have seen them in the brochures. (Photoshop can put a stove and fire anywhere ) It would seem that this would be ok as long as there is a proper wall thimble and double wall pipe connects the stove to the thimble. Simpson makes an adjustable DVL 6" pipe that will go from 6" to 9" that might work for connecting the stove. FWIW, the Castine can get hot. My preference would be to exceed the recommended back clearance by at least a couple inches. And yes, you will need 18" of hearth in front of the stove door. Note that with rear-exit, the pipe must be pitched upward slightly. From my experience, the F400 does not like a level pipe for rear exit.

One note of caution. What if you decide you want a different stove in a few years? The odds of an exact alignment for the new stove are slim. Is there any remote chance of going straight up with the pipe on the interior instead? That would give you more future options as well as better draft and perhaps a cleaner flue. The other option would be to go straight up 4-5ft, then 90 into the wall thimble.

 

[Noah]

I hate typing long post because they look intimidating to read, sorry.

I was just reading the installation instructions for the DVL double wall stove pipe and it shows the DVL connecting to the wall thimble with a minimum of 2" from the wall for a rear exit stove, figure #4 in the DVL close clearance instruction. Although I don't see how that is possible since the minimum clearance to combustibles for the DVL is 6".

I left a message with Dura-vent so hopefully they call me back soon.

 

[Noah]

I've never done a straight out installation, but have seen them in the brochures. (Photoshop can put a stove and fire anywhere ) It would seem that this would be ok as long as there is a proper wall thimble and double wall pipe connects the stove to the thimble. Simpson makes an adjustable DVL 6" pipe that will go from 6" to 9" that might work for connecting the stove. FWIW, the Castine can get hot. My preference would be to exceed the recommended back clearance by at least a couple inches. And yes, you will need 18" of hearth in front of the stove door. Note that with rear-exit, the pipe must be pitched upward slightly. From my experience, the F400 does not like a level pipe for rear exit.

One note of caution. What if you decide you want a different stove in a few years? The odds of an exact alignment for the new stove are slim. Is there any remote chance of going straight up with the pipe on the interior instead? That would give you more future options as well as better draft and perhaps a cleaner flue. The other option would be to go straight up 4-5ft, then 90 into the wall thimble.

If I were to use the 6" DVL that would put the stove at 12" from the wall, I will have to see what that would look like in the room and how that will effect my hearth design. I'm not really too concerned with getting a new stove any time too soon and if I do I'll just start over. After doing it once it should be easier the second time, right?

The stove can be vented out through the roof but I really want to avoid crawling around in my attic if I can. If it's possible to do I would like it to exist straight out the back. If not I will go straight out the top because I don't like the look of the wall thimble half way up the wall.

 

[begreen]

Just remember the F400 is draft sensitive. Rear exit straight into a cold exterior chimney in a cold climate may give you a balky starting stove + creosote if the wood is not quite dry. If you can vent it straight up, it will perform much better. And with a straight-up connection it will be done once and done right. Maybe hire a carpenter to handle the attic and roof work?

 

[Noah]

Just remember the F400 is draft sensitive. Rear exit straight into a cold exterior chimney in a cold climate may give you a balky starting stove + creosote if the wood is not quite dry. If you can vent it straight up, it will perform much better. And with a straight-up connection it will be done once and done right. Maybe hire a carpenter to handle the attic and roof work?

If the chimney is enclosed in a chase as recommended by Dura-vent will it still perform poorly?

The problem with my attic is the amount of additional insulation that was blown in by the previous owners. They sprayed it in from the vent at the peak and it is super deep. Not a fun place to work but I'll do it if I have too.

When I get home I'll explore the through the ceiling option more. What would you recommend for clearance behind the stove? I have the rear heat shield and no wall protection and I plan on using DVL pipe. Minimum clearances according to Jotul would be 7" and I was planning on about 8".

 

[begreen]

Gotcha. It does sound like negative fun in the attic, but with the Castine in particular, the operation will be better. That would require completely clearing the area of the stove pipe for the installation. Need a big vac or lots of garbage bags to accomplish this. I wonder if any insulation companies offer this as a service? Enclosing the pipe in a chase would help, particularly if it was insulated on the 3 outside walls.

I had mine in the corner with 9" wall clearance and the walls were about 130 degrees at the hottest. There's no harm in adding more distance.

 

[Noah]

So I ventured into the attic last night and it was about as much fun as I thought it was going to be. I helped re-wire a 1950's house a few years ago and that was much worse because it was all fiberglass and my blown in is fibrous so I guess I can tolerate it. I think I have been convinced that the straight up installation is going to be the best way to go, and it will be cheaper too since I'll be buying less insulated chimney. My trusses are laid out in a way that I don't have to deviate from my initial placement. In fact it gives me more flexibility because I don't have to worry about centering a wall thimble between studs.

My next question though is how close to this stove can a person sit with out being uncomfortable? Now that I can place the stove anywhere along the wall I want to make sure it is not going to cook someone sitting at the dining table.

 

[begreen]

Good to hear that this is doable. It will be a PITA, but in the end you will have a better functioning flue and stove. And the flue placement will be more flexible.

How far away is the table from the proposed stove location? You could sit a few feet away and just be toasty warm. 4-5 feet and no issue at all.

 

[Noah]

Good to hear that this is doable. It will be a PITA, but in the end you will have a better functioning flue and stove. And the flue placement will be more flexible.

How far away is the table from the proposed stove location? You could sit a few feet away and just be toasty warm. 4-5 feet and no issue at all.

With the stove in the center of the wall it was about 3' away from the stove, it's seems like that might get a little toasty for the person closest to it. I moved it off center towards the living room more and I'm going to widen the hearth back towards the table so there is a place to stock some wood in the vicinity of the stove. I'll take some pictures when I get a little farther along. Today I did complete the wooden frame for the part of the hearth that the stove will sit on and I think tomorrow I'll add the extension to it.

It looks like I might have to shim the hearth a little bit because my floor isn't as level as I thought it was. There is about a 1/4" gap in the middle between the floor and the bottom of the hearth.

 

[begreen]

Sounds good, I'd like to have our hearth set up that way. BTW, be sure to have an insulation shield surrounding the pipe in the attic.

 

[Noah]

I will be sure to follow the instructions to the tee. The insulation shield is only 15" tall and at first I was worried that it wouldn't be tall enough but I think my insulation is about 10" to 12". Which is good because I wasn't looking forward to framing it in up there.

Here is my progress so far. The cardboard on the left is the extension where I want to stage wood. There is a pencil line on it about 5 or six inches from the pad that indicates 15" from the stove and the minimum distance to combustibles. Good thing the pictures don't show very good detail, I'm not the greatest carpenter and had to miter the corners free had. There will be some Durock on there soon enough to hide the deficiencies.

 

[Noah]

So I posted these pictures on a tile forum for some feed back and suggestions on the tile layout but got a bunch a posts about the combustible materials and clearances. According to the manuel all I need is noncombustible material and I'm well within the clearances to combustibles on all sides. The guy at the stove shop even said to build it this way. Is there anything I'm missing that I should be concerned about?

 

[begreen]

Maybe they took the picture literally and thought the tile was going to be directly on top of the wood? With the bottom heatshield + ashpan, the F400 stays pretty cool underneath.

If the stove does not have the bottom heatshield, then the hearth needs to be built to R 2.0 value. But if it does have the bottom heatshield the hearth just needs to be non-combustible. If you want to be extra safe you can put a layer of sheetmetal (can be thin 28 gauge) on the plywood before the durock underlayment and tile.

 

[Noah]

In the next few days I should be able to start setting the tiles on the hearth but before I do I had a question.

Should I have the hearth screwed down to the floor? I was planning on screwing some metal brackets to the back and then screwing the hearth to the wall studs and then hiding the metal brackets with some trim just to keep it form sliding around in an earth quake.

Most of the pictures I have seem the hearth looks like it is built from the sub-floor up where as mine just sits on top of my existing engineered wood flooring. I figured this would make adding to it or re-constructing it in the future easier if I were to get a new stove. I guess most of the pre-fab pads just on on the floor though don't they?

 

[begreen]

It'll probably be fine with the brackets. Living in an earthquake zone, so my preference is to have everything anchored securely. The last thing I want to see in an earthquake is a fully stoked stove walking off the hearth.

 

[Noah]

The only thing holding the stove in place is it's own weight but at least all 400 pounds are distributed to 4 small legs sitting on rough tile so it shouldn't slide around much. The hearth on the other hand would slide across that slick laminate if not anchored, so I think your right, the rear brackets should be enough to keep it from going anywhere.

If I get a chance I will post some progress pictures tonight. I ended up ditching the mosaic border pictured above in favor of cut to fit slate tiles. I'm much happier with the way it looks and hopefully I can get the tiles set and grouted in the next few days. I'm getting really ancy to get the stove in place and start work on the chimney. This summer has been a cool one and it feels like fall is setting in already, I want this thing burning soon.

 

[Noah]

Here is the current hearth progress. Tomorrow I plan on grouting and after it cures I can get the stove on there and start working on the chimney.

 

[begreen]

Nice job Noah! It's looking sharp even without the stove on it.

 

[eightpilot]

Wow...That looks nice. 8

 

[Noah]

The hearth is finished for the most part and the stove is home, I just need to put the trim on the back to hide the metal brackets. I have spent the past week researching and pricing out chimney systems and I decided on the ICC Excel system. After reading all of the instructions for the other systems this one seems like it is the most installer friendly. According to ICC it is also the only 1" wall chimney that meets the ULC requirements for 3 30 minute fires at 2100 degrees, that sounds good to me. The dealer also gave me 20% off for buying a whole system which saved a good bit of money. I was going to try and get it all installed to day but the rain just wont quite so I'll think I'll have to settle with getting the ceiling support installed.

I want to put blank cover plates on the receptacles behind the stove but I was worried about plastic and metal ones getting too hot. Has any one ever seen covers made of porcelain or some kind of glass? Since glass is a good insulator I thought it might make a nice cover. Or should I just not worry about it?

 

[begreen]

Looking really nice Noah. Don't worry about the receptacles. I think they'll be fine. The F400 doesn't get very hot behind it that low. But if concerned use a metal cover.

 

[Noah]

Today I got a break in the rain and decided to get the chimney installed. Everything went pretty smooth and I was able to finish it up in good time. Of course since it wasn't raining it was sunny and 60 degrees out side but I just couldn't wait to have the first fire although it is a small one.

It took a little bit to get a fire going, I think it was a combination of me never doing it before and possibly not dry enough wood. I can tell this is going to take a little prctice before I master it.

 

[gpcollen1]

Looks nice and good job. I am in the process of buying a used F400 - with the double doors. Nice to see you got it done so quickly. Did you use single wall pipe inside?

 

[Noah]

That's the ICC double wall Ultra Black.

The stove works excellent, it warmed up the house very well. I can't wait to see how it performs in the below zero temps.