Insulated Shed for Curing Tobacco on the Northern Prairies

[ChinaVoodoo]

This shed was designed primarily to save energy heating it. It's main purpose is curing tobacco; however, structurally it is also intended to handle hanging meat. The outside dimensions are 5'3"x8'. The inside dimensions are 48.5"x85"

The shed began with 6 precast concrete footings, supporting three 4X8 beams. I dug a foot down, put in a layer of crush and adjusted the depth of the crush to level the footings.

It is considered a skid, and is technically movable so I can legally place it "temporarily" beside the house.

The floor is 3/4" plywood. Plywood instead of osb because plywood breathes better. Walls are 2X6 studs on 24" centers.

I left the end open while doing construction. I eventually closed the end and put the door on the side.

The ceiling joists are double 2"x6" and are held on with hurricane ties, or whatever they're called.


On top of the ceiling is the roof. There is a 2x12x10', and two 2x6x10'. They extend beyond the walls to provide an overhang.

Roofing is a corrugated asphalt product called Ondura. It was less expensive than polycarbonate and I thought it looked better.

 

[ChinaVoodoo]

I insulated with Roxul. It is less likely to mold, is more fire resistant and offers a higher R value than fiberglass.



The door in the side.

I put 2x4 cedar along the ceiling and midway on the wall to support the hangars.

Made sure to leave a hole for and pre plan the electrical.

Now here's where the magic is at. It is completely sealed. In Cold weather, the slightest leak would cause massive amounts of condensation inside a wall. So on goes hard foam insulation. Every joint, will be sealed with either calking or spray foam.


Not shown is the floor. I put a 3" thick piece of foam on the floor. It is sealed in all corners with spray foam. On top of that are loose cedar fence boards.

 

[ChinaVoodoo]

The heater is a tool box with ducting and fans attached. There are four light sockets inside. I am currently only running three of them with 300W light bulbs. I haven't pushed it to the limit yet, but that 900W has had the room up to 149F. That's a testament to the sealed multi-layered insulation.

The humidifier is a tote with a large filter in it. One hole in the lid has a fan blowing in. On the other side of the filter is another hole in the lid which lets humid air out.

I tried to design a dehumidifier; you might see a copper pipe coming out of the wall, then back in. It did not work, so I disconnected it. However, The two pipes coming through the wall, with a small fan blowing in one pipe acts as an excellent vent and accomplishes the dehumidification I wanted. So no worries.
The hangar columns are 2x2 cedar. I think you can see in the photo that they are screwed into the two horizontal 2X4s on the long wall.





I put large eye hooks in the ceiling joists to ensure a solid place to hang animals.
I haven't finished the exterior yet, and I would like to improve the door insulation.
No door photos, but essentially it seals flat against the outer wall around the door frame, rather than inside the door frame like most doors. This makes for a tight seal.

 

[Gavroche]

Nice work...

beau travail !

 

[Jitterbugdude]

Impressive! and clever idea the way you did your roof beams.

 

[deluxestogie]

View attachment 18968

Great shed design. That span of the hanging rod should be capable of holding 40 to 60 leaves at a time, and still offer adequate air flow.

Bob

 

[ChinaVoodoo]

I'm still learning how the shed is going to work in different situations. 900W of light bulb power keeps it at 165F no problem. The humidifier is perhaps oversized. I just ran 350ish leaves for two days at 100F 85%, one day at 118F 53%, one day at 135F, and 37%, and so far half a day at 165F. The humidifier hasn't had to turn on once. I'll be pretty confident leaving for a week in October while I air cure the last of the crop.

 

[Brown Thumb]

Very nice work. Is it completely sealed on the inside.

 

[ChinaVoodoo]

Very nice work. Is it completely sealed on the inside.

There are two 3/4" conduits running through the wall. There is a small fan attached to one of them. With the controller set to dehumidify, the fan maintains the humidity by blowing air in. Exhaust comes out the other pipe.

 

[Brown Thumb]

In a sealed chamber like that. I would not think you need a humidifer if you are air drying.
If flue curing that's a different story.

 

[ChinaVoodoo]

In a sealed chamber like that. I would not think you need a humidifer if you are air drying.
If flue curing that's a different story.

I didn't really expect it to be that sealed. I do need the humidifier after to bring it back into case for packaging though, so I'm glad I made the humidifier. I might remake it smaller though.

 

[satisfied smoker]

Perfect K.I.S.S. I dont mean the rockband, but Keep It Simple Stupid.
I like this idea, we have an old shed, I will do this also, thanks!

 

[greenmonster714]

Your always building some cool stuff CV. Nice job.

 

[Charly]

Congratulations ChinaVoodoo ! (a little bit late, but I have not seen this post before...)
That's a very nice job ! A great shed !