Converting Two Car Garage to Workshop - What would you do?

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Forum topic by Dallas posted 01-29-2019 08:53 PM 6126 views 0 times favorited 41 replies Add to Favorites Watch
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73 posts in 4305 days

01-29-2019 08:53 PM

Topic tags/keywords: workshop layout electrical shop new shop plan new workshop building workshop

The wife, newborn and I moved into a house with a detached two car garage in Decatur, GA. I am beginning my plans to convert it to a workshop. It has a bonus room above that is finished into an office. I’m somewhat starting from scratch. So, I wanted to get advice on how to do it right from the start.

What would you do if you were me?

Here’s the info on the space:

- 246” wide x 256” long x 96.5” tall
- two car garage door facing north
- concrete slab, drywalled, uninsulated
- 50amp sub panel for garage & bonus room above – (2) 15 amp circuits for garage: (1) for 11 wall outlets on three walls. (1) for four light bulbs and garage door opener. – (4) 20 amp circuits for lights and plugs in bonus room + (1) 220v/20 amp circuit for heater/ac window unit in bonus room.
- one entry door on west wall
- no windows or plumbing

Here are my priorities:
- hand tool and machine woodworking focused
- adequate power for power tools
- heating and air conditioning in some form (live in Georgia)
- dust collection and air filtration
- sufficient insulation and sound dampening
- LED lighting
- ability to move tables and machinery against walls to allow us both to park if the weather is bad. We will not park in the garage on a daily basis.

Here’s my current plan that I call “do it right the first time”. After trying to move as much as I can out of the garage, I will:
1. remove drywall from walls and ceiling (save as much as possible)
2. pressure wash floor, degrease, repair cracks in concrete
3. install meter and new 125 amp panel in garage to replace 50amp.
4. wire dedicated 220v circuits for compressor, dust collector, Mini-split HVAC, 3hp Table saw, electric car charger
5. wire circuit for lighting
6. wire (2) 110v/20amp circuits for wall mounted receptacles at 52” high, alternating circuits from receptacle to receptacle.
7, rewire/repurpose some of the circuits in the bonus room that are overkill.
8. caulk and weather seal around slab, studs, windows, doors
9. install one window on west wall and one window on east wall
10. install fiberglass insulation
11. install new insulated garage door
12. lean to shed – enclose, soundproof and insulate space under exterior stairs on South wall to house dust collector and compressor – lean-to shed extension to back wall of garage, sorta
13 run compressor and dustcollection lines (before or after drywall?) from lean to throughout garage
14 install mini-split
15 wire any audio / cat 5 if needed
16 paint floor – epoxy? just stained? garage floor paint only?
17 install two layers of 5/8” drywall using green glue sound absorption caulk in between each layer
18 tape, mud, sand, prime, paint with high gloss paint in light color to maximize light reflection and reduce saw dust sticking to walls
19 install lighting
20 install dust collection and compressor lines, if appropriate at this stage
21 install air filter
23 install band saw, jointer, table saw
24 install cabinetry and miter saw station
25 install french cleat systems for wall hung tools
26 create sanding station
27 create drilling station for drill press, bits and power drills
28 install compressor
29 building wood storage and clamping storage
30 create multi-function assembly table (like Pauk)
31 create flip top mobile tables for planer, grinder, spindle sander
32 drink beer

I’m mocking it up in Sketchup, but I’m still not even close to done.

Dallas Bentley

-- If a tree falls in the neighbor's woods, and no one is there to hear it...can you take it home, mill it and turn it into a coffee table without your neighbor making a sound?

41 replies so far

View DannyW's profile


360 posts in 1137 days

#1 posted 01-29-2019 08:58 PM

I’ll be watching this since I am in the process of updating my finished attached 2-car garage. I am mainly adding 110v branch circuits (2), possibly a 230v circuit, and lighting to replace the single dim light fixture. I am not looking to do any extensive changes since I will be retiring in a few years and most likely moving, but am interested in what you come up with. Good luck!

-- DannyW

View Bill White's profile

Bill White

5362 posts in 5300 days

#2 posted 01-29-2019 09:17 PM

Glad to see that you’re planning to insulate. That, and electrical work, would be my first priority.
Sounds as if you have a good plan.
Beer? Do it now, then call your banker.

-- [email protected]

View BlasterStumps's profile


2223 posts in 1779 days

#3 posted 01-29-2019 09:34 PM

If you haven’t already, I might suggest to put ‘getting an electrician to advise on the electrical’ right up at the top of your “plan” bullet list. I say that because you are planning to have some large tools running. The transformer, service conductors, main breaker and panel along with whatever size conductors are feeding the garage now from the house, all need to be taken into consideration. Even if it is possible to put in the sub panel you mentioned, you don’t want to be turning on your equipment and dimming down everyone’s lights or causing problems with appliances or electronics.

-- "I build for function first, looks second. Most times I never get around to looks." MIke in CO

View Dallas's profile


73 posts in 4305 days

#4 posted 01-29-2019 09:45 PM

Good call on the electrical, Blaster Stumps. Had a guy quote me last Friday.

$2,000 for new meter, new line from meter to garage. 125amp panel. All the circuits. He said that is enough for my list of tools running but I’d have tear down the ceiling drywall down and run the trench from the meter through the backyard to the garage myself to run the wire to get that price.

That’s serious money so I’m doing research. More quotes…

-- If a tree falls in the neighbor's woods, and no one is there to hear it...can you take it home, mill it and turn it into a coffee table without your neighbor making a sound?

View BlasterStumps's profile


2223 posts in 1779 days

#5 posted 01-29-2019 09:52 PM

I’d say he is pretty close to correct. Wonder what size the transformer is serving your house and how many neighbors does it serve?

-- "I build for function first, looks second. Most times I never get around to looks." MIke in CO

View Peteybadboy's profile


4359 posts in 3289 days

#6 posted 01-29-2019 09:53 PM

Any height in the ceiling to add racks for wood storage? If so I would to that. I added a spit a/c (I live in ft. myers) and it works great. I insulated the doors my self, that can save you big. Add Real good lights, window’s are great but you loose wall space. You would be surprised how valuable that can be. if you epoxy the floor don’t add the sprinkles, (drop a screw it’s harder to find) I would do something to help sweep up the dust and stuff. Also, check out storage solutions on LJ, I did a hand drill station, that really works, I use it all the time. good luck with this project. Don’t plan too much, you will change things as you work in the shop. Enjoy the process.

-- Petey

View clin's profile


1128 posts in 2336 days

#7 posted 01-29-2019 10:29 PM

Seems to me you have a lot of it thought out. I also question adding the windows, again due to losing so much wall space.

I wouldn’t bother trying to salvage drywall. Seems like way more work than it is worth.

Doubling up drywall for sound proofing is probably not all that necessary or helpful. No question more mass helps, but your garage door is going to be a very weak link for sound proofing. But, it’s not that hard to do so nothing wrong with doing it. Just be sure to account for the extra thickness when installing the electrical boxes.

Certainly all the sound proofing you can manage for the DC and compressor shed. Since you will be building that from scratch and it is small, I’d go all out on that and do a room inside a room. Though given you have to vent the DC there’s a limit to how helpful that would be.

The mini-split is a great idea as is the insulation. You can insulate your own garage door, but it likely won’t be as well insulated as one you can buy.

You mentioned putting electrical outlets high at 52”, consider having some low as well. You may want to access power under a workbench. It’s just so easy to put in more outlets when you have it all opened up.

Didn’t notice if you said this, but consider outlets in the ceiling. You may have something like an air filter you want to mount to the ceiling, as well as you may find you would rather drop a cord down to a machine rather than runnign it across the floor. Again, something that is easy to do.

As for flooring, when I converted part of my garage to a shop space, I used PVC tiles. There’s a wide range of these from thick and expensive to thin and much less expensive. I got thick ones costing about $5/sq-ft, so certainly not cheap. But there are versions that are less the $1 a sq-ft.

They are also plenty durable for parking a car on and in general they are often sold as premium garage flooring.

They are very durable, easy to lay down, much easier on your feet than concrete. Also, soft enough that a dropped tool is much less likely to get damaged than dropping on concrete.

When adding the mini-split, consider getting a two zone version and stick another head in the room above the garage. Much better than using a window unit. Especially if you will use the room often.

-- Clin

View RDan's profile


205 posts in 3663 days

#8 posted 01-29-2019 11:13 PM

If you can run a sub off of your existing panel, run the trench and put in Conduit x2 run cable in 1 and network cable in the other, or as a spare. Around here it is the meter head that costs money along with the other service fee. I live in WI. If heating with electric, figure 1 or 2, 5000W heaters that need 30 Amp circuits each or follow many others that look at Mini-Splits. Dan

View Steve Peterson's profile

Steve Peterson

429 posts in 4422 days

#9 posted 01-29-2019 11:19 PM

I question the need for a 125 amp panel, especially since it seems to need a lot of added components including a new meter.

I ran a garage workshop with a 50 amp panel. This included a 5hp tablesaw, a 5hp ClearVue dust collector, lights, small air conditioner, and an overhead air filter all running at the same time. The two 5hp loads are each on their own 30 amp breaker. The key is that they should not both be started at the same time. I had the window mounted 120V air conditioner on one circuit and all other 120V loads (lights and air filter) on the other circuit to balance the load. All the 120V devices were probably under 10 amps, leaving 40 amps total for the heavy 220V devices. I also had a 3hp bandsaw and other smaller tools, but they would never be running at the same time as the table saw.

The biggest limiter might be if you need a 20 amp 220V air conditioner for your environment. This would leave only 30 amps for all your other tools. This should still be enough for a 3hp table saw and a 3hp dust collector. The key factor is that this works for a 1 person workshop where only 1 primary power tool will be running at a time.

-- Steve

View Dallas's profile


73 posts in 4305 days

#10 posted 01-30-2019 12:04 AM

I d say he is pretty close to correct. Wonder what size the transformer is serving your house and how many neighbors does it serve?

- BlasterStumps

I don’t know the answer to that BlasterStumps. How would I find that out?

Our main panel served by the existin meter is 200amps and is pretty full. 50 amps goes to the garage. From what I understood, he would update the meter and/or update an add a nee one. Then there would be two shutoffs at the meter – one for each panel – Garage and House.

The garage sub panel has two breakers taken up as a main shut off to that sub breaker, which seems superfluous. That’s just breaker space though, not really taking up amps.

- Petey -

Good ideas on the flecks for the floor. I don’t like the look of them. Seems busy.

I’ll peek behind the drywall in the ceiling if there is space to work with for storage.

Good thoughts on the windows and not overthinking it. Definitelt overthinking it as I think about the need for windows!

- clin -
You second the question for the need for windows. It’s not huge, so that is a consideration. I just always read about the value of natural light. Dunno.

Yeah I figure the more windows and doors, the more double drywall would be a waste. As is salvaging any left over. Messy stuff when removing.

Good thoughts on the DC venting. Hadn’t considered that.

I wonder what plugs I’d need at a lower level…

I’m putting a 220v in the ceiling to drop down to the table saw. The saw will be somewhat centered in the garage with an outfeed table, router table and bandsaw set up as a sort of island of tools there in the middle. I will have to gameplan the power for the other machines as well. Possibly from the ceiling.

Where did you get your vinyl flooring? I only see that for shops with show cars online. No woodworking uses in action.

I will get a mini split with two air handlers (zones). One for each level. This raises the price/BTUs but I hear it is more efficient.

- Dan –
The electrician looked at the 50amp line that serves the subpanel currently from the main panel which is 200amp. He said he could run a new line from there, but recommends against it since i’d still be stealing amps from the house and the wife might be mad if the dryer cuts off when I’m cutting something. I’m still not sure about the new panel though…

- Steve Peterson -
I could, conceivably, coexist with the 50 amp panel now. It feeds the bonus room as well though. So, I wonder exactly how many things I could run at the same time. Dust collector, HVAC, table saw and garage lights but nothing else upstairs at the same time? Seems like I’d be cutting it close. This is why I’m getting feedback. It will be one person and most likely one tool.


-- If a tree falls in the neighbor's woods, and no one is there to hear it...can you take it home, mill it and turn it into a coffee table without your neighbor making a sound?

View Holbs's profile


2388 posts in 3369 days

#11 posted 01-30-2019 12:44 AM

why remove the drywall? blown-in insulation in walls and ceiling would be fantastic to keep your shop temp controlled and help with sound. And I believe fire code is to have fire-X rated drywall between garage and horizontal/vertical living space.
Yep..add electrical outlet (110v and 220v) in ceiling for future reel extension cords. I only did a 110v and it gets used all the time.
If ever to build your own woodworking bench (example: roubo), a large window in the backdrop helps greatly. So keep that in mind about windows.
Dual zone lighting. Incase, one zone blows a fuse while you are operating machinery with spinning blades.
Color scheme: I went sunrise/sunset two toned walls. Brightens up the place :)

-- The Carpenter Bee is derived from the Ancient Greek word wood-cutter "xylokopos/ξυλοκὀπος"

View BlasterStumps's profile


2223 posts in 1779 days

#12 posted 01-30-2019 12:46 AM

transformer size is probably fine but it is always best to know what it is when you add load. A call to customer service at the power provider to request the information by giving them your address or possibly meter number should be what you need. The power provider will generally size a transformer for the collective given load plus some. What that ‘plus some’ is, I am not sure. I doubt that it would be much in the excess because they don’t want excess KVA sitting out there idling for no good reason.

-- "I build for function first, looks second. Most times I never get around to looks." MIke in CO

View clin's profile


1128 posts in 2336 days

#13 posted 01-30-2019 02:08 AM

I think this was the PVC flooring I used:

From this web site:

But shop around and get samples first. It’s a weird thing were I think many of the online sources are really all the same source. But each has different pricing. Quantity matters with pricing. And this stuff is HEAVY, so look for free shipping or be sure to factor that into the price.

Price is pretty much tied to thickness (weight) and versions, like I used, with hidden locking versus types that don’t have that. Some like mine are also have water resistant seams. That matters if you pull wet or snow covered cars in.

I used the coin pattern. Obviously anything with any sort of texture is a bit harder to sweep than say a smooth epoxy floor. But I vacuum rather than sweep and have no trouble with that.

Also, things in the shop don’t roll on it as easy as a smooth floor, but it’s not an issue. And in fact it helps a bit. My garage floor slopes towards the door (common I believe) and my table saw would wander rather like a shopping cart on a sloped parking lot. It of course locks down, but sometimes I need to momentarily take my hands off while moving it around, so nice it will stay put.

Though I suspect the softness of the PVC tiles is more than enough to keep it from rolling on it’s own. And there are different textures you can get like diamond plate and some very light texture. Though with my testing of samples, the coin pattern vacuumed easiest.

The least expensive and quickest to install are these PVC garage mats or rolls:

This is about the best photo I have of my floor right now. Though it’s really a photo of an assembly table. One box of tiles was darker than the other so I had to mix them in to form a pattern. So that’s why there’s that darker one. They did give me a discount for that or would have replaced it, but I discovered it mid install and didn’t have the time to get new tiles.

I’m happy with it. Though would have preferred a wood floor, but not only is my floor sloped it transitions from horizontal to sloped and it would have been awkward to get a wood floor to follow that. So I’d do this again given the choice.

-- Clin

View Mainboom's profile


92 posts in 1097 days

#14 posted 01-30-2019 03:47 AM

do not tear down the drywall. hire a electrician or just buy a fish tape and fish the walls for your electrical. have a 125 amp main lug installed for a sub panel. you will regret tearing down that drywall because your not gonna be able to save much if any of it. scrub the floor with a brush and epoxy coat them. then put tools in it… all this worrying about the size of the transformer where you live is just insane. im not gonna give the math on it but the power companies plan them for a given amount of power per hour. which most neighbor hoods never touch. if your having brown outs you live in California which I wont get into. so stop worrying about transformers. Sry for the rant.

if you wanna be getto about it and not fish the walls you can use emt pipe and run your wire through it. but some places that is not code so you have to check city codes. which is why if I was you id hire an eletrican for maybe 2k. save the drywall and the headacke .

Building your own garage and drywalling it in not as fun as you have been lead to believe. I just finished a 24×30 with loft. I built it alone wired it alone drywalled it mostly alone. my wife the electrican did not help me wire it she told me what was wrong and I did it over. 3 time to be honest yea im not an eletrican. point being if you have an eletrican wire it for you you wont spend the money on the drywall. the time the effort and the falling off the ladder. let alone buying scaffold a drywall jack or renting one. lets not talk about mudding the thing. so by time your all said and done you could have paid an eletrican to do it for you. all you have to do is epoxy the floor and put tools in it and go to work. if you can swing it don’t be a hero. pay someone so you can do what you really wanna do. it took me almost 3 years because I work and don’t always feel like jacking with it. and no one really wants to help you unless they get paided. just being honest

-- CRANE OPERATORS START EARLY because iron workers need their heros ready when they wake up

View Manitario's profile


2818 posts in 4223 days

#15 posted 01-30-2019 04:33 AM

Having had the electrical done for 3 different shops, your quote of $2000 seems quite reasonable, if not slightly low. I would not try and make due with the 50amp panel that you currently have. Could you make it work? Yes, but it would be super annoying and your wife would hate you as mine did when I had a similar setup in one of my shops and the lights would dim every time I’d start my TS. If you are essentially building a new shop out of the garage, do it right and get a good electrical setup. My current shop is 1200sqft and I only have a 100amp panel, which has been more than adequate while running my machines.

-- Sometimes the creative process requires foul language. -- Charles Neil

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