Site work · No. 3
Insulation, drywall & electrical
A bare steel shell is a fine place to park a tractor and a miserable place to work in February. We fur the walls, insulate them, run the wiring and the lights, and hang and finish drywall — so the building stops sweating and starts being a room.
Insulation & condensation
The first job isn't warmth, it's dew point. Steel panels condense, and water dripping off the roof onto your tools is the complaint we hear most.
Warm, humid air inside meets a cold steel panel and gives up its moisture on the underside of your roof. Insulation solves it only if the vapor barrier is on the warm side and the assembly is sealed, which is why we treat air sealing and insulation as one job rather than two.
Closed-cell spray foam applied straight to the panel is the belt-and-suspenders answer: it air-seals, insulates, and stops condensation at the surface where it would form. Faced batt in a furred cavity costs less and works when it's installed carefully. Reflective double-bubble is the budget option and is better than nothing under a carport roof, but it is not what we'd put in a heated shop.
| Option | Typical R-value | Good for | Watch out for |
|---|---|---|---|
| Closed-cell spray foam | R-6 to R-7 per inch | Heated shops, cabins, anything finished | Highest cost; has to be sprayed before furring |
| Faced batt in a furred wall | R-11 to R-19 wall | Walls behind drywall | Vapor barrier must face the warm side |
| Blown or batt at the ceiling | R-30 to R-49 | Finished ceilings under a vented roof | Needs airflow above the insulation |
| Reflective double bubble | About R-3 to R-4 | Unheated storage, carport roofs | Not enough on its own for a heated space |
R-values are manufacturer typicals for planning. We spec the actual assembly to your building and how you intend to heat it.
Furring, framing & drywall
Drywall doesn't go on a metal panel. It goes on the framing we build inside it — which is also what everything you hang on the wall will hold onto.
- Wood or steel furring fixed to the building frame
- Cavity depth chosen for the insulation you want
- Blocking where cabinets, shelves, and brackets land
- Interior partition walls for offices and bathrooms
- Drywall hung, taped, and finished ready for paint
- Or steel liner panel if you'd rather hose the walls down
Not every building wants drywall. In a working shop, a steel liner panel takes abuse, wipes clean, and never gets a hole punched in it by a ladder. In an office corner, a bunk room, or a cabin, drywall is the right call — it takes paint, it takes trim, and it reads like a house instead of a garage.
We'll usually mix them: liner panel to four feet or across the work bay, drywall on the finished end. Tell us how the space gets used and we'll lay it out that way.
Electrical
Wiring goes in while the walls are open. This is the part people regret undersizing.
Power to the building
A detached shop usually gets a feeder from the house panel to a subpanel in the building, run underground in conduit. That trench is dirt work, so we dig it while the excavator is already on site and sleeve through the slab before it's poured. Size the feeder for what the building will draw with everything on, not for a single circuit.
Inside the building
Subpanel, receptacles around the perimeter, 240-volt circuits for a welder, compressor, or lift, LED high bays or strip lights laid out for the bays, switching at both doors, exterior lights and outlets, and a dedicated circuit for the mini split. We leave spare capacity in the panel on purpose.
- Underground feeder and trench from the house or meter
- Subpanel sized with room to grow
- 120-volt receptacles spaced so cords stay short
- 240-volt circuits for welder, compressor, lift, or EV charger
- LED lighting laid out to the work areas, switched at each door
- Rough-in coordinated with insulation so nothing gets buried wrong
Electrical work that requires a licensed electrician is done by one, and we schedule around whatever inspection your county calls for.
Do it in the right order
| Stage | What happens | When |
|---|---|---|
| Sleeves & trench | Conduit through the slab, feeder trench dug | Before the pad is poured |
| Shell up | Building delivered, set, and anchored | Delivery week |
| Furring & partitions | Framing fixed to the steel, rooms laid out | After the shell |
| Rough-in | Wiring, boxes, any plumbing rough | Before insulation |
| Insulation | Foam or batt, vapor barrier to the warm side | After rough-in |
| Drywall & finish | Board hung, taped, finished, painted; devices trimmed out | Last |
Skipping ahead is what makes finishing expensive — every stage out of order means opening something back up.
Questions we get a lot
Why does my metal building sweat?
Spray foam or batt insulation?
Can you hang drywall directly on steel?
Do you handle the electrical permit and inspection?
What circuits should I plan for in a shop?
Can I heat and cool a metal building?
Can you finish a building I already have?
Get the inside finished
Tell us the building size, how you'll heat it, and what you plan to plug in. We'll price insulation, wiring, and drywall as one scope.