Building science in the garage/workshop?
Hi. I am in Zone 4a near Nashville and it is a very wet, mixed-humid location.
I am trying to determine how much air sealing I should be using on a workshop? I will use either post frame or 24″ O.C. 2x walls. Heat will probably be wood and radiant. Cooling will likely be open doors/windows.
I will spend a lot of time working in the shop 20hrs a week. Therefore, I would like it to be fairly comfortable work environment.
I am thoroughly sold on building science for my house when we build it; however, I have been planning to apply the same ideas to my shop and starting to wonder if I am being too extreme for a workshop?
Therefore, I wanted to ask wiser men their opinion on how far would you go on a workshop?
My pockets are shallow, but I do not want big regrets.
Thank you for your advice.
-Mike
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Air sealing is not all that difficult, so based on your comfort goals I don't see why you wouldn't shoot for sub 1ACH50. Is this just a workshop, or combination with a garage? Air sealing a garage door is going to be more difficult. You might want to keep the garage area as a separate room, with an air tight door between it and the workshop.
More of a creature comfort suggestion. Natural light makes a big difference for a workshop, if designed in, it can also reduce the winter time heating needs.
For example a high row of windows shaded with an overhang on the south side like this:
https://plasticinehouse.com/wp-content/uploads/2018/06/Natural-Ventilation.jpg
Gets you fair bit of free heat in the winter when the sun shines, but limits any solar gain in the summer when the sun is high.
If you make a couple of the elements operable, with the door open, you can get really good convection driven ventilation in the summer time.
Trevor, the workshop area will need to be accessible to bringing in a trailer, so they cannot be separated. However, I did find a pretty nice barn door setup on a Matt Risinger Video recently: https://www.youtube.com/watch?v=BHiGVkiIVJ0
Akos, I really like that idea of bringing in natural light. I will need to solve one major obstacle though. While the building does run E/W it has a full length shed roof on the south side for outdoor storage of equipment and materials.
While the doors in the video look nice, in general sliding doors like that are troublesome.
My favorite doors are double-doors that open outward. You can make each door like a section of of wall -- 2x framing sheathed on both sides. Then you can insulate it the same as the walls and put windows in it. Get some hefty hinges and weatherstrip all around.
Of course the ground has to slope away from the door for this to work -- but it should anyway.
You can jog the shed roof at the windows. Bit more complicated to build though.
High windows on the north side also work quite well. These give very nice diffuse light throughout the day, bit more of an energy penalty in the winter.
Natural light in a workshop is a big plus.
This is a tough one, one I've wrestled with, as there's a lot of factors at play.
I can't think of many reasons to preclude air-sealing, however I can think of quite a few to make sure you have adequate (read thoughtful and bomber) ventilation / dust control, etc.
When it comes to adding significant expenses (like adding bunches of insulation, expensive windows, etc) you could view it as simple ROI and you might find you wouldn't build it out tremendously. To figure this out would take some hard figuring with a lot more specifics.
But I imagine there are more factors than cold hard ROI and you just want to make sure everything 'is sensible.'
My gut, which is seldom wise, would be to go for air-sealing, a good ventilation system, point source pollutant collection (i.e. dust collector), 'moderate' insulation and 'decent' glazing. Be sure if you're burning wood to supply combustion air.
As far as doors: I've yet to build this, but my current hair-brained scheme for a super-tight barn style door is to make it 'hanging' and 'sliding' (as much a wall—like DC says). The idea is to hang it somewhat loosely (or on a double pivot) so it's free to move in the 'z-direction' in it's entirety (in towards the structure). This allows the door to be heavy as high-water (since it's hanging) no worries about opening clearances (since it's sliding) and a bomb air-seal since it can be face sealed all 4 sides like a space-ship coming in for docking. Might be an unusual (finicky?) build and tough to make sense of the hardware though. Locking idea is a few sets of lever type clasps to grab hold of the door and pull it in tight (picture the locking mechanism on a drop-down cargo trailer door or the like).
Deleted