Thought I would add a few odd cents into the discussion. I have been building a garage/workshop for myself. Doing nearly all of the construction myself (from the foundation up) in order to afford it. In all, it is roughly 1500 s.f. -- 900 s.f. garage / workshop downstairs and 600 s.f. woodshop upstairs. I'll mainly present the downstairs for this discussion since that is where the automotive / metalworking is done.
First, if you have the option, go with a detached garage. Then you don't have the noise, dust, and dirt connected to the house. The significant other will love you for it! <img src="/forums/images/graemlins/lol.gif" alt="" />
For electric, I had a 200 amp service to the original house. I had the electric company upgrade the service to 400 amp (they call it a Class 320 service) and then split the service to run to the 200 amp panel in the house and a second 200 amp panel in the garage. Best decision that I ever made. I put 20 amp receptacles about every six feet so that one is always handy. Also ran 220V around and just have blank plates over the electrical boxes for any future needs. There is a 220V by the overhead door for stick welding outside. With the 200 amp panel, I have more than enough circuits out there for everything.
I painted the floors with a industrial two part epoxy system from Rustoleum. As was mentioned, welding can be an issue. I have a few little round burn marks where globs of molten metal fell. I have since bought a welding blanket from Harbor Freight and that seems to be the ticket for protecting the floor. There are some scuff marks here and there, but I have drug stuff across it and driven my Bobcat skid loader in there and spun around a few times as well. Only real problem is a couple places that water has gotten under the epoxy paint and lifted it right off the concrete. One spot was near the man door where water leaked in under the door. The other place was at a side wall where water got in. Both places I have corrected the leaks, just a matter of getting some more paint and touching it up.
I went the extra distance and drywalled the interior. Some may consider that a luxury, but I consider it a good investment. First, it regularly gets down into the 20s in the winter here and does drop below zero. So I insulated the garage. The kraft paper on batt insulation is coated with tar, so it burns. Drywall is a fire barrier. I went with 5/8" drywall, which is fire rated but also is much more impact resistant than 1/2". Don't even consider 3/8" drywall. Cold may not be as much of an issue in Texas, but perhaps it would keep the heat down as well?
Painting the drywall a light color does wonders for brightening up the shop. I've spent too much time in dingy dark basements and garages without adequate lighting.
Which brings me to the next topic. Lighting. I went with 8' high output cold weather fluorescent fixtures. Lights the shop up better than daylight. As I said, it gets cold around here, so I needed the cold weather ballasts -- good down to about -20F -- otherwise the tubes just flicker in the winter. I have the switches for these lights at the back of the garage, away from the doors. They only get turned on if you are working since it takes them awhile to fully warm up. You don't want to flip them on for just a few moments. The switch at the door turns on a separate circuit of a few incandescent fixtures spaced around the first floor to just give a good general, overall lighting. That way you are not flipping on the big guns just to find a screwdriver for a project back at the house.
The garage space is divided in half. One side has two "drive in" bays with separate garage doors. The floor slab in those bays slopes back towards the door so that rain / snow / slush falls off the vehicles and drains back out the door. The other half is level so that you have a surface to work on without things rolling around.
My ceilings are 10.5 feet, but I wish that I had gone higher (12' or so) so that I could put in one of those lifts eventually. The truck is not a problem to get under <img src="/forums/images/graemlins/smile.gif" alt="" />, but the cars are a bit of a pain...
For heating on the first floor, there is radiant tubing under the slab. The eventual plan is to put in a boiler and have radiant slab heating on the first floor and radiant baseboard on the second floor.
There is a stationary compressor that will be plumbed throughout the building. Centralized dust collector on the second floor, but I had not thought of the shop vac system on the first floor. Have to look into that.
Right now, storage is mainly industrial metal shelving and cabinets that I scored from the local kitchen remodeler. When they redo a kitchen, they pull out all the old cabinets, cart them back to their shop, and leave them in the alley. When they have a slow moment, they bust them up and chuck them in their dumpster. If any of the cabinets walk off before they bust them up, less work for them. These are not pretty cabinets, but most of them are solid wood and plywood from the days before everything was made of particle board. You're not going to store third members and transfer cases in them, but they are fairly heavy duty and FREE!
Right now I am finishing up the drywall and starting in on the ceilings. Then just a matter of getting all the receptacles and light fixtures in. Been working on it for years. Had to put it on hold for awhile while life took some unexpected turns.
The disclaimer. I've spent my life working for architects, engineers, and contractors. Right now I am working on getting my architecture license. I realize that not everybody would have the inclination to do this, but for me it is part therapy, part quest. If I could make a living designing and building ultimate garages and workshops for people it would sure beat the speculative offices and other unimaginative projects I am working on now!<img src="/forums/images/graemlins/sleeping.gif" alt="" />
If anyone is interested, PM me and I'll send you a couple pictures.
