building insulated, heated barn/garage

[bgrimes77]

Good afternoon.

I'm in central Maryland. I'm looking to build an approximately 30' X 30' storage barn/garage. I want a standard entry door plus a large, sliding "garage" type door as well.

I'll be using it mostly to store equipment like a tiller, tractor, and misc junk my wife doesn't want in the attached garage. I may also finish a portion to use as my man headquarters. Nothing too fancy, just a place I can maybe sit and tinker with cars and stuff, build things, or maybe even stick a TV out there.

So, I want to heat it and insulate it as well.

Few questions:

1. In my climate (a touch colder than Wash DC or Baltimore), what type and R-value of insulation should I use? What's the most budget friendly?

2. What type of construction?

3. How do I calculate heating needs? there will be natural gas available. Most of the time I'll probably only heat to about 40 degrees just to keep liquids from freezing. I might kick it up to 65 if I'm going to be out there any length of time (I do have a remote controlled thermostat picked out) but I don't expect to be able to sit out there in winter in a t-shirt and boxers either. Mostly just keep it above freezing. The challenge with R-values is the metal sliding door will of course lose a lot more heat than the insulated remainder of the structure, right?

4. I may, if budget allows, wall off a much smaller area as a seperate room to be my man cave and heat that warmer than the rest, even with just a space heater, so I can cheapen up my heating needs for the entire building.

What type of foundation is best in this situation?

 

[wssix99]

What type of foundation is best in this situation?

It sounds like a pole barn is the type of thing you are after. Minimal foundation required.

The challenge with R-values is the metal sliding door will of course lose a lot more heat than the insulated remainder of the structure, right?

I think you are on the limiting factor here. If you put an uninsulated barn door on an insulated barn, from a heat perspective its just like having a giant open window. It will stop the wind - but that's about it.

I think you should really evaluate your doors before going further. If you want uninsulated doors or want to keep the barn door (insulated or uninsulated) you should fall back on your plan to have a smaller heated space within the barn.

If you insulate the whole thing - IMO - you don't gain much by insulating beyond what your big doors will provide. (ie: If your doors are R-11, you get quickly diminishing returns if you insulate the walls to R-19.)


Heating the whole space will be expensive with regards to gas usage. The cost of heating the space will far outpace the money you would spend on insulation - so insulate as much as you can. (Using smaller doors and fewer windows also helps.)

Another thing you will want to investigate and plan for is insulating the concrete slab.

4. I may, if budget allows, wall off a much smaller area as a seperate room to be my man cave and heat that warmer than the rest, even with just a space heater, so I can cheapen up my heating needs for the entire building.

If you do this, you'll need to raise this section above the main floor by 8"+ so that flammable fumes (heavier than air) can't get to your space heater. That may change your overall plan.

 

[bgrimes77]

Okay, I did a little more research in the meantime while waiting for a reply to this post. So thank you for your reply. What I did find, is there are insulated overhead doors out there. But the our values are for the center of the panel, not the entirety of the door. However here's a question…

During the winter months, it is unlikely I will be using the overhead door at all. I will probably only be utilizing it through the smaller entry door. So, could I gain anything by perhaps putting additional insulation temporarily over the inside of the door during the winter? For example, maybe some bubble wrap and/or just throwing some fiberglass insulation and trying to seal it as well as I can?

 

[TTTTTT]

You can buy even at Costco, garage door insulating kits that attach to the inside of the panels. I'm sure they are easy to put on and then off in the spring when you don't need them. I'm sure other places have them as well.

 

[RickP]

During the winter months, it is unlikely I will be using the overhead door at all. I will probably only be utilizing it through the smaller entry door. So, could I gain anything by perhaps putting additional insulation temporarily over the inside of the door during the winter? For example, maybe some bubble wrap and/or just throwing some fiberglass insulation and trying to seal it as well as I can?

The big problem for me is the air infiltration around the edges of a standard garage door. It's pretty bad, even with weather stripping. I don't heat my insulated garage, but I'm a little further south than you, so winter temps are a little more moderate for me. It's pretty cold out there in the winter, but nothing freezes. I have a refrigerator in the garage, which does provide some heat, but I've thought about adding a big gas heater just to get it to 60 degrees or so if I'm working out there. I probably wouldn't run it all the time though.

If you decide to heat your garage, you might consider using radiant tube heaters on the ceiling, which will heat the floor instead of the air. You might reduce the effects of the air infiltration that way.

 

[wssix99]

So, could I gain anything by perhaps putting additional insulation temporarily over the inside of the door during the winter? For example, maybe some bubble wrap and/or just throwing some fiberglass insulation and trying to seal it as well as I can?

Sure. If you want to do that, I'd suggest having wall, hung like a door, that you can swing in and out of the opening and maybe stuff some insulation around the cracks to seal things up. You can insulate that secondary "door" like your walls. The garage door kits don't really do much.

BTW - I'm a big fan of the radiant floor.

 

[rancherbill]

Heating and cooling is an expense forever.

Insulation - meet or exceed whatever is code for residential spaces.
Door - Sliding doors are hard to get and keep a good air seal in wind. Consider a conventional overhead door.
Here is a very good floor design for cold climates that will pay for itself over time.

 

[rburke65]

You have the opportunity to buy isolation once verses buy energy forever. Good luck.

 

[ms fowler]

Pay attention to infiltration versus insulation. I am hoping to be in the same situation in a few months. I am considering blocking around the garage door during winter months to stop the infiltration. Insulating to R30 makes little sense if air is blowing in and out, changing the air in the room every few minutes.

 

[911mike]

I have a 42 x 80 stick built barn with a 24 x 24 work shop inside. The shop was a separate pour with infloor radiant heat. 2" of insulation under the slab and all the walls (exterior and interior) are 2x6 with 2" of spray foam and R14 wool insulation. Ceiling is R50 blowni in. I heat it all winter to 60 and cost me 60-70 a month. The rest of the barn I heat as needed with a 200K BTU bullet heater as needed.

You buy insulation once and the cost of energy will always increase so pay now or pay more later.

 

[indyjps]

It's worth the time to look at radiant floor heat. This requires an insulated slab and a frost wall on the slab to be most effective. If you trench the loops deep you may be able to get away with just running a pump to circulate, and use ground temp to keep the building above freezing. It will add significantly to your up front cost, but your maintenance coat will be low.
If it were me, I'd split the building into 2, heated and un heated, gravel the equipment side and wall off and insulate the slabbed work side.

 

[NUTTSGT]

When it comes to insulation, remember it's an investment. Try to buy it once and be done as it will continually pay itself back over time. While you may not expect to use it much right now, what does the future hold ?

 

[theoldwizard1]

Do you want the whole thing heated or just the "man cave" portion ? This will make a big difference on the style of construction and a big difference on heating and cooling

If you want the whole 30x30 "conditioned" I would build with SIPs. More expensive, but the insulation is included in the price and overall it is "tighter" construction. If only the "cave" is going to be conditioned, a pole building is more cost effective.

Rancherbill is right on. Heating and cooling bills show up every month. You ABSOLUTELY want at least 2" of rigid foam and vapor barrier underneath the entire slab. It will make a big difference, even if you don't heat/cool the storage area.

If you plan on working in the storage area a lot, I would seriously consider a radiant heated floor. It is the most comfortable heat you ca get for a large space.

I would seriously look into the price of a mini-split heat pump for the cave. Yes, it will be more expensive than a gas furnace, but when you add in the cost of A/C you are close.

 

[kbs2244]

You may not have any say in this decision.

I just learned that in my county that if an "auxiliary" building is going to be heated it has to meet a new federal "suggestion" that, in effect, requires 6 inch wall insulation.
This will require all stick built, heated, garages to be 2x6 studs.

The Feds make the suggestion and the county makes it code.
No mention is made as to the amount of heat planed.
Just if any heat is planed.

Check with your building department.

 

[theoldwizard1]

You may not have any say in this decision.

I just learned that in my county that if an "auxiliary" building is going to be heated it has to meet a new federal "suggestion" that, in effect, requires 6 inch wall insulation.
This will require all stick built, heated, garages to be 2x6 studs.

Structural Insulated Panels (SIPS) !

 

[bgrimes77]

Good info. Thanks again - this gives me something to research.