Insulating and heating a shed.

[CommittotheIndian]

I am in need of some advice and it looks like there are some knowledgeable individuals in this forum. I haven't quite found the answer that closely relates to my situation so I'd appreciate any response.

I have a 10x16 smart barn with two 4 foot lofts and a metal roof. I plan to use this space as a small woodshop and recently determined I need heating & possibly AC. I live in Central Indiana (zone 5).

Based on my research I believe I'm going to use a mineral wool insulation in the walls and possibly the ceiling. I plan to hang some kind of wall board (not likely drywall but still undecided). I wasn't planning to close the ceiling (just insulate) but I'm also not opposed to it.

My questions:
Do I need a vapor barrier on the walls or ceiling?
As you can see in the picture, I have gable vents (two - one each side). How should I handle these? Do I need other ventilation, baffling in the ceiling, plug these vents? I'm so confused.

I think the walls are pretty easy (besides the question on the vapor barrier). It's the ceiling that has thrown me down a rabbit hole of research.

Again any advice would be greatly appreciated. I also haven't decided on the heating/cooling unit (maybe window unit, maybe mini split) so if you want to share two cents there as well, it's highly welcome.

Thank you all for any help provided.

 

[dcg9381]

I think the typical residential style answer on the roof is to build and insulate attic space (IE,insulate an attic floor).
If it were me, I'd look into spray foaming the roof and keep the additional space. Generally, you can't DIY spray foam due to the economics being favorable to contractors, but I'd look at something like tigerfoam and shoot the roof deck.

 

[CommittotheIndian]

I think the typical residential style answer on the roof is to build and insulate attic space (IE,insulate an attic floor).
If it were me, I'd look into spray foaming the roof and keep the additional space. Generally, you can't DIY spray foam due to the economics being favorable to contractors, but I'd look at something like tigerfoam and shoot the roof deck.

Just to make sure I'm following your response. The typical answer would be to continue the loft floors across to make one big closed attic?

But your suggestion would be spray foaming the roof, no additional ventilation, vapor barrier concerns, etc?

 

[duneslider]

What are you intending here. Will this be climate controlled 100% of the time, or just when you are in there working?

 

[dcg9381]

Just to make sure I'm following your response. The typical answer would be to continue the loft floors across to make one big closed attic?

But your suggestion would be spray foaming the roof, no additional ventilation, vapor barrier concerns, etc?

Traditional insulation is typically laid across the attic floor. You certainly can (and I have seen) bat insulation stuffed into rafters, so I guess that's possible too. Foam is just by go-to on roof decks, but that's mainly due to the advantage of air conditioned attic space.

Yes, I'm suggesting a one off DIY (TigerFoam) of the roof deck. Foam insulation is typically done without attic vents - meaning no ridge vent, no soffit vents.. You build a sealed envelope. I don't think doing traditional insulation in the walls changes that much.

I can't speak to vapor barrier concerns. I assume a lot of that is climate based (I read differing opinions on Barndo forums). In my state the vapor barrier breaths... And in the case of your building, it's not something that I'd likely go back an add.

 

[CommittotheIndian]

What are you intending here. Will this be climate controlled 100% of the time, or just when you are in there working?

100% more than likely. It is suggested my CNC not be stored in a space below 40F.

 

[duneslider]

If you will be using a minisplit or something it should help maintain humidity. I would close up that vent and just insulate however you want. Some additional vapor control would be nice but with how unsealed that door looks it isn't going to be keeping a lot of air out. Seal it up best you can and insulate best you can and you should be fine. Vented roof assemblies need air flow to help prevent moisture accumulation but that isn't the situation you have going on. If the minisplit (assuming that is what you are using) isn't keeping the humidity down then you may also need a dehumidifier, not sure what humidity is like where you are.

The better insulated this is the less your heater/ac has to run. You could do spray foam but I am not generally a fan of it but it does have some advantages.

 

[thammel]

I can't tell if there is also a ridge vent. I also don't believe you have soffit vents. So the only vents look like the gable vents. In any case, I would use Roxul or equivalent mineral wool insulation and insulate all the walls, door and ceiling. That in itself will make a huge difference. Then since you are running power to it you have a choice of a mini split heat pump (if you want to keep it cool in the summer too) or just electric heat for the winter. I did the same sort of insulation in my 12x16. I put OSB on a couple of walls for the hanging system I used for yard tools. I had a ridge vent and soffit vents so I used styrofoam baffles under the mineral wool from soffit to ridge. I also have gable vents but just covered them over. The one area I could not address was floor insulation. Just have to live with that.

 

[Jim greengo]

If you're going to have benches/shelves along the walls you might want to put outlets up higher.

 

[CommittotheIndian]

I can't tell if there is also a ridge vent. I also don't believe you have soffit vents. So the only vents look like the gable vents. In any case, I would use Roxul or equivalent mineral wool insulation and insulate all the walls, door and ceiling. That in itself will make a huge difference. Then since you are running power to it you have a choice of a mini split heat pump (if you want to keep it cool in the summer too) or just electric heat for the winter. I did the same sort of insulation in my 12x16. I put OSB on a couple of walls for the hanging system I used for yard tools. I had a ridge vent and soffit vents so I used styrofoam baffles under the mineral wool from soffit to ridge. I also have gable vents but just covered them over. The one area I could not address was floor insulation. Just have to live with that.

I do not have a ridge vent or soffit vents, just two gable vents. So would you worry about baffles in my situation?

As others have said, I’m thinking I’ll have enough ventilation with the gable and door (plus no insulation for the floor).

 

[CommittotheIndian]

If you're going to have benches/shelves along the walls you might want to put outlets up higher.

Thanks, I think I’m covered there. There are 18 outlets in here, 4 are just below the ceiling. I have an outlet in every other bay.

 

[duneslider]

I do not have a ridge vent or soffit vents, just two gable vents. So would you worry about baffles in my situation?

As others have said, I’m thinking I’ll have enough ventilation with the gable and door (plus no insulation for the floor).

If you leave the vents there all the heat/cool you make will just leave as fast as it can move through the vents. If you want to keep the conditioned air in the shed you need to close all the openings. Think about wearing a coat, what happens when you unzip it? The same applies to a building. If you have openings, air is coming and going.

 

[readhead]

Having sold lots of similar sheds over the years I can tell you what we do.
First. Did you have the floor insulated when you ordered it? If not I would suggest that you close off the bottom so cold air can’t circulate under the floor.
Second. Close off the vents. Since the entire building will be a conditioned space there is no need for vents.
Third. Use rockwool or fiberglass to insulate. If you aren’t going to finish the roof you may want to run some wire to keep the insulation in place. For your use I don’t see a need for a vapor barrier but if you want to go ahead. It will be on the inside. We would insulate the doors with sheets of rigid foam and use brass weather striping on the doors at the bottom to keep the mice out and foam weather strip on the top and sides
Fourth. It is only 160 square feet. Once it is insulated you can heat it with a candle. We would install one 2’ baseboard heater. Since you want cooling the smallest heat/cool mini split would work. I had a shed for an office at my lot and I used a space heater in the winter and a portable AC unit vented through the wall in summer.
This is pretty basic so don’t overthink it.

 

[CommittotheIndian]

Having sold lots of similar sheds over the years I can tell you what we do.
First. Did you have the floor insulated when you ordered it? If not I would suggest that you close off the bottom so cold air can’t circulate under the floor.
Second. Close off the vents. Since the entire building will be a conditioned space there is no need for vents.
Third. Use rockwool or fiberglass to insulate. If you aren’t going to finish the roof you may want to run some wire to keep the insulation in place. For your use I don’t see a need for a vapor barrier but if you want to go ahead. It will be on the inside. We would insulate the doors with sheets of rigid foam and use brass weather striping on the doors at the bottom to keep the mice out and foam weather strip on the top and sides
Fourth. It is only 160 square feet. Once it is insulated you can heat it with a candle. We would install one 2’ baseboard heater. Since you want cooling the smallest heat/cool mini split would work. I had a shed for an office at my lot and I used a space heater in the winter and a portable AC unit vented through the wall in summer.
This is pretty basic so don’t overthink it.

THANK YOU SO MUCH!

I have read so much on this that it just jumps back and forth. One thread, forum, person, video says do this another says that.

I did not get the floor insulated but I'm looking at the idea of ridged foam board under neath if I have enough gab to reach and install (not likely but I guess on the sides to keep airflow from circulating under would be better than nothing. Then it's just ground contact to worry about heat loss.

I'm not opposed to finishing the roof, just didn't give it a lot of thought yet.
I like the fourth. I know this space isn't huge and doesn't need to be the best situation, I just need to keep my equipment safe. Trying to decrease all this research & knowledge into my situation has been stressful.

I really do appreciate you breaking it down into my situation, it really helps.

 

[acer66]

Not sure what a smart shed is or if it matters.

I would put extra effort in sealing the building envelope so you avoid any draft and entry ways for insects.

I also would choose mineral wool like Rockwool insulation over fiberglass anytime.

Good luck.

 

[BillK]

What is on the outside ? If its sided did they use any type of building paper or wrap between the siding and the osb ?

 

[thammel]

No need for styrofoam baffles. As said above, close the gable vents. Block off the underside to keep air flow minimal under the floor. I never intended to heat mine, but I did block off the floor ends with close mesh wire screen just to keep animals from going under it. Bottom line - it will be easy to keep it warm or cool with such a small volume.

 

[gba2331]

My approach would be to try and seal as much of the roof and eaves as possible and then insulate (maybe consider foam on the floor and cover with another layer of plywood). You could also put in an air barrier but I’d prefer sealing closest to the outside. A handheld spray foam gun and cans are cheap and easy.

I wouldn’t be worried about a vapor barrier because the space is so small, you’re not living there (and dumping in moisture by breathing, washing, etc). The hvac needs will be minimal but i would recommend some type of dehumidification to protect your tools. Running a dehumidifier works but will make the space hot in the summer (plus you need a drain or have to empty the bucket often). A window a/c unit will cool but may not dehumidify sufficiently.

A mini split IMO is the best option because it can provide heat at low outside temps, dehumidify at lower temps (say 70 outside), and provide cooling. I should really get off my lazy backside and put one in my garage.

 

[dshop]

spray foam insulation all the way around...then add a refurbished PTAC ($350 approx), and all your concerns are taken care of and you will have a nice workable space. don't cheap out and complain later. get it right the first time and be done with it.

 

[CommittotheIndian]

spray foam insulation all the way around...then add a refurbished PTAC ($350 approx), and all your concerns are taken care of and you will have a nice workable space. don't cheap out and complain later. get it right the first time and be done with it.

Any reason spray over mineral wool insulation?

I’m not completely opposed to it just not sure it’s something I want to attempt.

 

[acer66]

Any reason spray over mineral wool insulation?

Normally you spray first and then mineral wool etc.

 

[dshop]

spray foam takes care of everything. just do it from the floor, across the ceiling and down to the other floor...totally encapsulated.

 

[dave*99]

Any reason spray over mineral wool insulation?

I’m not completely opposed to it just not sure it’s something I want to attempt.

Normally you spray first and then mineral wool etc.

I think he is asking: Is there any reason to prefer spray foam instead of mineral wool insulation?

 

[gba2331]

Spray-only is faster, spray + mineral wool might be cheaper, mineral wool only won't stop air as much (which may not be a problem in a shed, you might consider using caulk instead for air sealing).

 

[acer66]

I think he is asking: Is there any reason to prefer spray foam instead of mineral wool insulation?

Yes, my bad.

 

[75gmck25]

There are three heating/cooling requirements you need to attack.
- Stop air infiltration
- Stop heat/cold conduction coming in through the outside surfaces
- Moisture/humidity control
And then add the complication of an uninsulated floor that is hard to access from underneath.
I don't think humidity from inside is a big problem, since you don't live and cook there, so I assume you are trying to seal humidity out.

Spray foam is an excellent choice because it covers air flow and conduction at the same time. However, for a building that small it may be too expensive. Spray foam contractors need a minimum amount of expensive equipment and well-trained people to do the job properly, and that does not scale well for a small job. Do-it-your-self foam is also an option, but I don't know if you would get good results. Its harder than it looks.

If it was my shed I would probably take this track.
- Figure out how to add insulation and sealing to the floor. Under the floor would be best, but not easy to do. Maybe something as simple as sealing the plywood floor seams, good carpet padding or thin insulation on top, followed by vinyl flooring or very durable industrial-grade carpet that stops air infiltration. It won't be well insulated, but will probably be enough.

- Use spray foam in a can or caulk to seal all the wall penetrations from the inside, including siding seams and the gable vents. Then add rockwool inside each bay and on the roof deck or ceiling (not sure which you are doing) and cover with sheetrock or plywood on the lower walls. If you insulate the roof I would probably try to cover it with drywall painted white. It holds the insulation, allows you to use the area between the trusses for storage or extra headroom, and the white surface would reflect light and make it easier to see in the shed.

- Install seals on the doors and windows so they are airtight when closed.

- Use a window A/C unit or a mini-split system that is both a heat pump and A/C to control temp and humidity. Boxing in a place to mount a window unit in the wall is the easiest, and it looks fine for a work area.

 

[Turbo900rr]

Op, I have the exact same setup. I went with fiberglass insulation with the paper backing, stapled to the studs and cheap paneling on the walls and ceiling. I have a 900 watt heater set at 55 during the winter and a 5000 btu ac I mounted in the wall, set at 78 in the winter. No rust or condensation issues.

 

[justinjoyal]

I would do fiberglass or mineral wool insulation, then vapor barrier. Make sure you seal all the little cracks here and there with spray foam before insulating and use acoustical sealant when applying the vapor barrier for better vapor proofing.