Structural Question about Wood Cook Stove

[Elucidus]

Hello, new here. We are looking at getting a wood cook stove (roughly 500-600 lbs seems to be the going weight estimating 3' x 3' in size). We have a two story house, with a basement and no attic. We have a large family and are looking at a decently large wood cook stove, but haven't settled on a model exactly. I am new to all of this and have been trying to figure out what I can do and see if it fits with what I want to do. OH we plan to install tile before we put this, and I am not sure if we would still need a hearth pad, but I assume we do which is probably another 100 lbs.

I have an interesting structural question. Most of my joists are 16" middle to middle, but where I want to put the stove is not. It is 16", to 12", to 20", to 15", back to 16". I have attached some pictures to show what I mean, and some drawings to help more for the measurements. The joists are 2x10s, with 12' 6" distance between the exterior wall and the support posts. I am not sure how to calculate how much weight per square foot since the joists are weird. Any help or advice would be appreciated. Thanks.

Joists:





To the support post:


To the exterior wall:

 

[EatenByLimestone]

I’d start with asking the town building inspector what he wants to see. Sometimes they can be pretty demanding. It’s best to know what you’re getting into from the start.

 

[Rearscreen]

If I was in your situation, since I like to do things myself, I'd most likely at a minimum sister on additional joists spanning the
outer wall and lolly column support beam (hidden by duct work in picture?) or I would find a suitable glue lam and sister them on in the same fashion.
The vent in the exterior wall picture is for?

 

[EbS-P]

If you are not worried about adding a cast iron tub full of water don’t be worried about the stove. It’s not a static load I would be worried about. Any big dance parties in the stove room would concern me more. Our piano weighs 600 pounds. Never gave it thought about joist strength.

 

[begreen]

The first thing to do is to get the stove's weight. Then find out its hearth requirements and decide the makeup of the hearth pad. There is a very big weight difference between a metal sheet under the stove and a layer of bricks.
A rigid hearth pad will help distribute the weight over the joists and this is adjacent to the wall for some support.

 

[Max W]

I can’t say what your floor is designed to hold but your stove and hearth won’t fall into the basement. 40 lbs / sq ft. is code minimum for a main floor. You do want to limit deflection. If there is an unseen carrying beam behind the duct on the two posts you show that shortens the span to 12’6” it is a very good start. I am thinking that the 4x4 held by a L bracket and fastened to the post with hose clamps is not there as a joist support. One way to add stiffness to a floor is with bridging. Bridging stiffens by sharing the weight on a joist with the joists on either side, across the floor. Bridging could be with 2x10s between joists or 1x4 s in an X pattern. There is also also steel X bridging that should be simple to install but I don’t know much about them. If your weight calculations turn out on the heavy side a beam extending the existing (?) beam maybe a little beyond the possible masonry hearth would provide additional stiffness.

ps prefab metal bridging would not work with the different distances between joists.

 

[Rearscreen]

I was intrigued by this post which I responded to it earlier. But just for fun I emailed my good friend who is an architect - previous builder. We usually go at each other with politics and this was a better exchange except, since I know him, I simply asked for a very simple "go, no go" explanation. His first response was "no." However, and he just couldn't help himself, the next email was:
Just for reference, you have to consider the following:
Species and grade of the joists.
Type and thickness of the sheathing.
Location of that area load in relation to the supports.
Other loading conditions. If it's not a sleeping area the live loading is 40 psf. Sleeping areas = 30 psf
That has to be added to the overall loading scenario.
Other potential dead loads, if any.
And floor performance ( is there a ceiling under this? and is it sheetrocked or sheathed with wood?
Setting of deflection limits.

 

[Elucidus]

Thank you everyone. There is a support beam in the middle of the house that runs the gambit, that the support post connect to, behind those ducts. I am not sure the purpose of the 4x4 that connects the two support posts.

I haven't decided on a model or even a make, I am still trying to figure out the best way to get the stove where I live, see what limitations there may be with delivery, and pick from the available options.

You guys have given me some things to think about, I had considered adding bridging throughout the basement ceiling because I think it would help stiffen the floor above, but that is a guess, based on a gut feeling. I had not considered adding another 2x10 in the 20" gap between the exterior wall and the support beam in the middle, but after you mentioned it, I think that may be the solution, maybe adding bridging to that as well. I tend to over engineer my solutions.

 

[Elucidus]

I was intrigued by this post which I responded to it earlier. But just for fun I emailed my good friend who is an architect - previous builder. We usually go at each other with politics and this was a better exchange except, since I know him, I simply asked for a very simple "go, no go" explanation. His first response was "no." However, and he just couldn't help himself, the next email was:
Just for reference, you have to consider the following:
Species and grade of the joists.
Type and thickness of the sheathing.
Location of that area load in relation to the supports.
Other loading conditions. If it's not a sleeping area the live loading is 40 psf. Sleeping areas = 30 psf
That has to be added to the overall loading scenario.
Other potential dead loads, if any.
And floor performance ( is there a ceiling under this? and is it sheetrocked or sheathed with wood?
Setting of deflection limits.

Interesting.

- I have no idea what the species or grade of the joists are, I will see if they are marked. The house is only 12 years old, if that helps.
- The sheathing above is 23/32" OSB
- 80" from the exterior wall and 34" from the support beam/post.
- This is in the kitchen area, the only thing near it would be the island, which would be a distance away for fire safety 18+ inches depending on setup.
- A ceiling under this? Not sure I understand, this is in the basement, there is no ceiling, the only thing below it is the concrete floor.

Not sure if the questions were just for me to know or if he wanted answers, but that is the best of the answers I can give. I do appreciate the effort.

 

[Rearscreen]

All I can add is that my friend has OCD, is a perfectionist, and is the opposite of my political persuasion. Again, I'd sister on some LVL's and be rest assured. It will be rigid. Sorry I can't get back to him with your specs in a back and forth as he's a professional architect and busy busy busy.

 

[Elucidus]

All I can add is that my friend has OCD, is a perfectionist, and is the opposite of my political persuasion. Again, I'd sister on some LVL's and be rest assured. It will be rigid. Sorry I can't get back to him with your specs in a back and forth as he's a professional architect and busy busy busy.

It's all good, I appreciate the response. I wasn't expecting an answer, but figured I'd respond anyway, just in case. I realized can't add a joist without cutting the plumbing that goes to one of the bathrooms, so I will probably stick with adding some bridging to add rigidity.

 

[begreen]

I just checked and a large commercial type 2 hearth pad weighs around 150-200#.