I have a 2400 sq ft shop so size seems OK (after 4.5 years working in it) -- for now.
BUT - I only built a 14' ceiling and now wanna put in a mezzanine - the vertical is pretty tight. A 16' ceiling woulda been better than my 14'.
I have
- 54x 110V outlets
- 5x 220V outlets
- in-floor heat
- commercial grade floor covering
- a lift
- a compressor
I have posted this list several times; one more can't hurt.. Folks here have already hit on many key points:
GENERAL
• Build as big as you can afford/fit on your property (or you'll regret it).
• You gotta know your plan inside and out – when the builder asks to move something elsewhere, only you can visualize the impact on other things / stuff
• Be flexible when reality shows up – also be true to your overall plan
• Windows? PRO: natural light – CON: entry point for a$$holes
• Skylight(s)? PRO: natural light – CON: then no attic
• Keep the building dimensions in multiples of 4 feet – reduces wastage of wood
• A mezzanine is good for long-time storage of large or awkward items; plan for where the staircase is gonna be placed; plan how to get heavy items up there and back down
FLOOR
• Gonna place light(s) in floor under lift??
• First thing you lay down is 10 mil vapor barrier
• Then closed-cell insulation – 2 inches thick
• In-floor tubing for radiant goes in before concrete pour – plan carefully if a lift is planned. Should be thicker concrete and limit pex tubing near posts
• Lay some plastic conduit in the floor before concrete is poured from the circuit box to the three other walls to allow future wiring to be run without tearing into walls or mounting conduit on the walls
o Since I forgot to do this, I installed a 2-3" PVC pipe in the upper left-hand corner of the circuit breaker box that terminates in the attic with another sweeping 90° curve. This easily allows fishing a new line (or two) into the circuit box. (See photo) The girts needed to be notched so the OSB would lay flat and metal straps were used to hold the pipe in place.
• Thickness? 4” works. Except under lift – my pour was 9-12 inches thick under posts.
• Plan now for smoothness of finish on concrete - - epoxy covering?
• Gonna wash cars in there – floor drain(s)? Lot’s of environmental issues to learn
WALLS
• 2x4 vs 2x6 construction. A 2x6 is pennies more per board and allows thicker insulation
• I have R19 in my walls (Colorado) and the building is noticeably cooler in summer and stays warm in winter even during sub-freezing temps
• I have R49 blown-in above the ceiling
• Sheath with OSB vs Dry Wall. Dry wall looks prettier but to hang anything heavy requires finding a stud or two. OSB has more industrial appearance (and can be a ***** to paint – think “sponge”) but a shelf goes wherever you want to put it
• Windows – already covered
• Height of walls? 12 or 13’ allows most lifts to fit (I have 14’ ceilings in main room)
• Tall walls require more heating capacity, and costs more to heat
ELECTRICAL
• Plan where your 110v outlets are gonna be, then add 50% more of them (mine are 4 feet apart except where a window gets in the way); I have 45x 120V outlets in my 2300 sq ft hobby shop
• Are you gonna use 15- or 20-Amp circuits? (different wiring requirements and different fixtures)
• Place them 45-48” above the floor level so they aren’t hidden later by benches, toolboxes, etc
• Plan for outlet(s) on the exterior of each wall
• Plan for outlet(s) in ceiling for lift or drop light or other
• Plan for outlet(s) in ceiling for garage door opener
• Plan for outlets up high on wall: wall clock, TV, modern “smart” speakers, other
• Lights – fluorescent or LED? Dimmable? Dimmable LEDs are available but require different wiring and dimming switch
• Plan for exterior lights – Colorado Code requires a light above each man-door opening
• Plan for exterior lights – gonna have a patio nearby or BarBQ pit or horseshoe pit or Christmas lights?
• Plan for dedicated circuit for heater
• Plan for dedicated circuit for water heater
• Now plan where circuits are gonna start. Each can handle 8-10 outlets and need to start with a GFIC outlet
• Plan where your 220v outlets are gonna be. Consider welders, air compressor, lift, oven (powder coating), special tools, etc. Even if you won’t have these until the future, plan now to power them.
WATER
• Gonna have water in the garage? A sink to wash up before going into the house is priceless
• Gonna have water in the garage? A sink to wash parts is useful
• A shower is priceless to avoid getting SWMBO’s towels and linens filthy
• Toilet?
• Hot water is nice to wash cars in the winter
• Plan a hose bibb on at least one exterior wall and maybe one inside
A/C
HEAT
• Gonna use in-floor PEX? -- see notes on concrete.
• If not, propane or electric heater will need power and proper placement and capacity
• See comments re height of walls
STUFF
What toys do you have? What toys do you
plan to have? Sketch your floor plan to scale on gridded paper; don’t forget to include windows, doors, and the circuit box. And then, to scale, place your toys. All of them. The easy ones are toolbox(es), benches, welders, air compressor, and the like. Did you remember to ID a place to store floor jacks? Creeper? Jack stands? Ladder(s)? Computer desk?
Find a place for place everything:
o Welder
o Plasma Cutter
o Grinder
o Polisher / Buffer
o Powder Coating Oven
o Blast Cabinet
o Parts Washer
o Microwave
o Refrigerator
o Charging station for cordless tools
o Desk lamp
o TV
o Stereo
o Computer
o Phone
o Wall Art / Neon signs
o Other
STORAGE
• Plan cabinet(s) to store hardware (nuts, bolts, washers, this and that)
• Plan cabinet(s) to store supplies, such as (paint, cleaners, paper towels, etc)
