Sugar house loft joists size

Quote:

---

Originally Posted by n8hutch

My span is only 10 feet to the center, I have an approximate 1000 gallon tank up there , even at 8000lbs, that is only 55lbs per square foot with a 12x4 tank... there are plenty of calculators online that will help you determine what you need.

https://www.awc.org/codes-standards/...tware/spancalc

---

N8: I don't agree with your analysis. If you divided the 8,000 lb load for the entire area of your loft then you would need some way of transferring that load evenly to every joist and uniformly on every joist to make that assumption valid.

For that kind a weight, I would be running at least a 2x10 joists at 16" spacing. But with that kind of weight, I'd be adding extra redundancy beyond the joist calculation and beyond the joists to the entire building framing.

The real purpose of a standard ceiling joist is to hold up the ceiling, not to support an additional load placed on top of them. Many a building has been damaged by trying to support a load from them. If you want to support a load, you need to make sure the structure is in place to support it properly. Otherwise the best you can hope for is that the joists and roof will be sagging after some time....the other possibility is collapse. Make the correct assumptions based upon data, do the analysis, and build it properly.

Quote:

---

Originally Posted by jrgagne99

Not enough information. You need to specify the span and where the weight will be (middle vs. edges vs. all over.) Suggest an online calculator, they abound.

---

I was thinking of running 10x10’s down the center of the sugar house for support columns. Leaving 12ft on each side. The weight would be in the center. Support columns I was thinking every 12 feet.

Quote:

---

Originally Posted by DrTimPerkins

Make the correct assumptions based upon data, do the analysis, and build it properly.

---

I agree. And just to be clear, my back-to-back steel L5x3x3/8 framing is not a typical beam configuration. I would recommend steel beam sections over L sections mainly because the design is more straight forward.

Quote:

---

Originally Posted by calvertbrothers

I was thinking of running 10x10’s down the center of the sugar house for support columns. Leaving 12ft on each side. The weight would be in the center. Support columns I was thinking every 12 feet.

---

I think you should be consulting with a structural engineer. I don't think a traditional carpenter should design this without professional help.

Also it sounds like the arch will be offset from the centerline of the sugarhouse. Are you thinking of a hood or open with a cupola? For the open option, the cupola should be directly over the rig.

Attachment 22337Attachment 22338

Your coupala can be off center this is how I did mine, while it doesn't have an engineers stamp it has been up 5 years and I am pretty sure it will stand for 100 more easy. If you are not comfortable designing your building for a loads get a friend to give you a hand that has done that kind of thing quite a bit. I personally tend to over engineer things and anyone who has actually been in my sugarhouse can see that. Good luck to you with your build/design. There's always more than 1 way to skin a Cat.

Quote:

---

Originally Posted by n8hutch

Attachment 22337Attachment 22338

Your coupala can be off center this is how I did mine, while it doesn't have an engineers stamp it has been up 5 years and I am pretty sure it will stand for 100 more easy. If you are not comfortable designing your building for a loads get a friend to give you a hand that has done that kind of thing quite a bit. I personally tend to over engineer things and anyone who has actually been in my sugarhouse can see that. Good luck to you with your build/design. There's always more than 1 way to skin a Cat.

---

Nate,
I realize that I was not that clear but I did not suggest that a cupola needed to be in the center for structural reasons. I was less clear that you would want a hood if your rig wasn't directly below your cupola due to the reduced effectiveness. It appears that you have a hood and steam stack. Without a hood, steam management can be a challenge even in ideal configurations. From your photos I can also see that the roof rafters run through the cupola, which I agree with regardless of the cupola location. As for over-engineering, I agree with that thinking and I apply it constantly. From a structural perspective, I look for extra member capacity, good alignment, solid load paths to the foundation, adequate bracing for global and member stability, and redundancy in the connections. For the average person - be very wary of specialized construction (like sugarhouses) and seek professional help when working beyond your ability.
Ken

Quote:

---

Originally Posted by n8hutch

My span is only 10 feet to the center, I have an approximate 1000 gallon tank up there , even at 8000lbs, that is only 55lbs per square foot with a 12x4 tank... there are plenty of calculators online that will help you determine what you need.

https://www.awc.org/codes-standards/...tware/spancalc

---

How did you calculate these numbers? The weight of sap at 2% is 8.34 lbs. per gallon so 1000 gallons would be 8340 lbs. A 12x4 tank is 48 square feet which calculates out to 173.75 lbs. per square foot.

Quote:

---

Originally Posted by n8hutch

Attachment 22337Attachment 22338

I personally tend to over engineer things and anyone who has actually been in my sugarhouse can see that. Good luck to you with your build/design. There's always more than 1 way to skin a Cat.

---

Nice interior. If I had built that I would have used a double header to receive those rafters...and joist hangers for the header, and joist hangers on the rafters where they tie into the header. That would have been over-engineered! :D

Quote:

---

Originally Posted by bill m

How did you calculate these numbers? The weight of sap at 2% is 8.34 lbs. per gallon so 1000 gallons would be 8340 lbs. A 12x4 tank is 48 square feet which calculates out to 173.75 lbs. per square foot.

---

I was wondering about those numbers myself. An 8340 lb. tank sitting on 5, 6, or 6 rafters is going to exert a serious load. 10x10 columns mid span and the weight directly over those columns will help. But, 8340 lbs. is a little over the weight of 2 Chevy K5 Blazers sitting over your head....I think some serious thought needs to go into the design of the loft.