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Building a new space - any advice welcomed


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I’m finally getting around to replacing a falling down garage and have the opportunity to build it back with an attached shop. As it stands now, it will be a 22’x22’ garage with a 20’x20’ shop (outside dimensions), both with 10’ ceiling height. Planning on 4” concrete floor for the garage and 6” concrete floor in the shop. I’m including a 2’ rebar grid with 2 1/2” - 1/4” wall sq rude at the intersections for tooling attachment points. Separating the shop from the garage, I plan on using a curtain of heat/flame resistant material (same stuff we’ve started to use on robot weld cells are roll-up weld shutters at work) with a 2”x6” along the ceiling to cover the gap from the curtain rod and loop. I’m going to setup the buffalo forge I have with a 10” side draft stack. (Not wanting to jump into a bricked forge yet, work be difficult to reconfigure if I don’t like the setup after a year or two...) I’m think a 60amp 220v single phase electrical service. Walls insulated with foam, but not sure yet if I’m going to insulate the ceiling or the rafters. Long term I work like to have actually power equipment (drill press, band saw, 2x72 grinder, power hammer... wish list you know)

I know others here have a tool grid in the floor and I thought I saw a name for it, but haven’t been able to find the name. I was planning on having 1/4” plate caps for the tube flush with the concrete, but talking with some they brought up a concern about the exposed concrete edge cast around the edge chipping/spilling away in use. Has this happened to anyone or was the edge around the cap “lined”?

Anything I’m over looking or over doing? I would prefer to do this right the first time.

Thanks,

David

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My advise is worth just as much as I’m charging you for it...  6” concrete for your shop is significantly more expensive and overkill unless you have specific ideas not mentioned.  If 4” is fine for your cars what will you be putting in that needs 6”?   2’ rebar grid would be overkill in my area too - 3’ would more than suffice.   A large power hammer would have its own footing.  Take the cost savings from your concrete and insulate the ceiling.  Heat and AC are really nice...  A double layer of 5/8” Sheetrock (or whatever local code requires) might be better than having a curtain?  

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The main reason for the rebar and spacing of it is for the tooling grid (2 1/2” - 1/4” wall square tube welded to the rebar intersections vertically, to give fixed rigid mounting points in the floor. I believe Frosty has this in his shop...)

The purpose of using a curtain between the garage side and the shop side so I can open it up for any projects that would need more space and provide space for hammer-in in the future.

I’ll have to put more thought into the 6” concrete, that could very well be overkill.

Thanks for taking the time to share you thoughts,

David

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I would also question whether a 6" slab would be worth it, but it is only an extra 2 1/2 yards of concrete so if it makes you feel better....Having a good base and proper install is way more important.

I'm not totally following what you are trying to cast into the floor. Typically I'm never a fan of casting any chase ways or power outlets into the floor. There is way to much risk of having them in the wrong spot, or having them get in the way in the future. It's just more trouble then it's worth and they usually get filled in later or just not used. Commercially it's rarely done, power, air, ventilation ect. are dropped from the ceiling.

I'm also assuming you want to keep the wall between the 2 spaces completely open? With just a curtain you will still get a lot of dust/dirt between the two. I would think an overhead door or double door might be better.

Finally, unless you plan on conditioning it year around, I don't know if it's worth the cost to spray foam. It provides a great air barrier and thermal envelope, but I don't know if it's worth it for a shop. I would think more along the lines of Zip panels and 2x6 walls with fiberglass batt insulation.

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Give consideration to heating the floor.  

Insist on an overkill method of parameter drainage as well as under the floor drainage to collect and remove any water or moisture.  

Waist high electrical outlets. Enough said.

Install a total electric kill switch to be used when you shut down the shop. Locate the switch near the main exit door.   Throw the switch when you leave at night and KNOW that there is NO electric in the shop.  You will sleep better at night. 

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They're called "Gozintas" because a pedestal tool Gos inta one. When you have the slab poured have the caps installed and well greased or you have to break the caps out of the floor. So the edges chip a little, you're not making a dance floor. If it gets bad a good concrete patch compound makes it right easily. Remember to grease the gozinta cap unless you want it cemented in place. :o

INSULATE the roof! Then install a vapor barrier and ceiling. The accident took me out before I finished my shop and believe me a propane forge under a bare steel roof starts raining on you in about 15 minutes. Any fire produces water vapor, don't think running coal will keep the rain off.

All the usual stuff, More: circuits, lights, outlets, 120 & 240v, windows, doors, etc. than you think you'll need.

If you work solo a 60 amp service MIGHT be enough but most any motor on a power hammer is going to want at least 50amps all by it's lonesome. I'll have to eek by on 100 amps. but I work solo virtually 100% of the time but I'd sure be happier with 200 amps. so I could use the lathe and cut off saw at the same time while the shop lights are on. 

Frosty The Lucky.

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Plan for Ventilation!   It can be a lot easier to get a good roof penetration when it's planned from the start rather than retrofitted. (I used to live near Castleton; I remember the mall being built... Rain, snow does happen out there!)

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I'm with Frosty about the 200 amp service panel and Glenn's shutoff kill switch. I don't have any but Gozinta's come in very handy and if I ever pour a complete concrete floor I'll definitely have a bunch of them, one of our club members shop has some and what a joy to anchor equipment temporally to them.

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Put in two roof vents, one pass through for the forge and one for blowing hot air out of the attic space.

Be sure and have a window opposite the door that can be opened and used to blow out or provide ventilation to the shop.  

Plan on piping the shop for compressed air. A connection at the man door, at the shop door, at the window, and at the work table will keep you from running hose.  Nothing like opening a garage door and having a compressed air out right there to check the air in a vehicle.  

Add a electrical outlet at the man door, and at the shop door for both 110v and 220v.  You would be surprised how many times you can plug something in right there.  Electric welders can roll right up to the door and you can then weld outside on a project that may or may not fit into the shop, like that trailer frame or gate.

Put floor drains in the the shop so you can if you want wash down the floor or clean up spills..  A sink is a welcome water source as well as a place to wash up before you go into the house, or get into the truck to go to town.  One tub minimum or two tubs if you like that style.

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I'm not a fan of concrete floors in a blacksmith shop. Concrete is very Hard on the feet and hard to mount tools. You can move or replace tools by digging and for many things, use RR ties for a foundation.

Spray it with mag chloride, the stuff the county sprays on dirt roads. It will make a great floor. Then once a week or so give the floor a good water soak and rake the high places into the low areas to get and maintain a good level floor. This also keeps the dust down and the fines end up being part of the floor.

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Of course water means that when it gets to negative 20 degF outside; the shop needs to stay above freezing!  If possible an "airlock" system of doors between the shop and the house to cut down on noise.

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I’m not sure if I can reasonably get much more power than that to the building, but I’ll look into it.

Master shut off for the shop, got it.

Getting water would be pretty easy, getting waste water out, would not.

Is the idea of in-floor heating a good option? I’m not familiar with that type of system or it requirements. I would also assume I would need to put insulation underneath the pad to help with efficiency there, wouldn’t that weaken the whole pad? Natural gas heat of some sort would probably work out best. I was thinking of radiant natural gas units, but those would introduce even more moisture. 

Ventilation, shop side will have a large man door, 9’x7’ roll up, and a window on the front and two windows on the back. Then a solid wall by the forge. Garage side 9’x16’ roll up, two windows on the opposite wall, and one window and another large man door on the remaining wall. Of course I will have a tall stack for the forge and figure out how to get a good second vent in. (I don’t want to loose all the heat in the winter.)

David

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You can put a damper in the forge chimney to close the draft down a bit when not in use.  If you use a side draft chimney, simply build a door or plug for the opening when not in use.

For the attic, you will not be using shop air.  You will be cross ventilating the space to blow out the attic heat.  For the roof, create an air space between the insulation and the roof.  This will create air flow from the soffits straight up to the ridge vent, cooling the roof.  A white roof (or light color roof) will lower the temperature of the roof and attic space considerably. 

If you want music in the shop, build in speakers and wiring.  Ceiling mounts do not get in the way of the work space.

Anyone mention a small refrigerator for the cold beverages? 

Place double the usual amount of light over the work benches.  Attach the lights to a motion detector so they are working when you are. (grin)

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even if you are using rebar, dont forget to add the 4 inch mesh its cheap and  does a lot for keeping it stable

In my shop I ran a 6 inch slab from 4500 mix,  with a 2 ft grid of salvaged 5/8 inch rebar and the 4 inch mesh.  I am in the flood plain so the ground is all  sand here.  I calc that I spent an extra 200 for 200 sq ft floor over the minimum required 3500 mix and no rebar.  Rather than footers I used 16 inch pilings with some rebar in them as well.   It is over kill I know. I also connected the electrical grounding to the rebar.

I wish I had put in a chimney damper

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A round chimney damper is just 2 holes in opposite sides of the chimney. Insert the damper and feed the handle in one hole, across the damper, and out the other hole.  Push and turn the handle to lock it into the damper.   Only trick is to be able to place the damper into position,   Everything else is done from the outside of the chimney.

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There are many other damper configurations.

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I've never thought of in floor heating in a shop. The only negative I can think of is drilling mount holes for equipment and "hitting water"!

Beyond that in floor heat is great! I've built two, manifolds and all, and both were "on demand". Very warm and very efficient.

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The trick to installing stove pipe dampers is to put them just BELOW the joint closest to the stove/forge. It lets you see and reach everything as you thread the handle rod through the damper and pipe. Vertical or horizontal doesn't make much difference. Trying to do it at arm length is fodder for funniest home videos. . . except the language of course.

The trick to avoiding drilling into in floor (PEX) heat tubing is to know exactly where it is. Mine runs in a straight line grid, Zip tied to the rebar that is heavily tacked to the Gozintas. If I need holes I snap a chalk line on the North side of the gozintas and don't drill within 1" either side.

Hopefully I'll be able to finish the shop enough to make it worth heating. Electricity is coming soon. :)

Frosty The Lucky.

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  • 1 month later...

Going slow, which I find frustrating!

Now going with a 200A service for the shop. It’s basically the easiest way for me. House has a 200A service and the next step up is 400A with separate 200A feeds. So, one for the for the house and one to the shop. (If I really wanted, I could do 3ph on my property, but not in a hurry to spend another $10K. Much lower than most due to having high voltage 3ph on the pole within 100ft of the new building,)

Decided the in floor heating is the way to go, at least for me. I’ll make sure I know exactly where the lines are!

Hold up is getting zoning approval. Current garage is maybe 30” from the property line but need 9.9ft on the side by code on my property and maybe pushing it for the 22ft clearance to the back out the property. So survey, site plan, and design all going to the planning commission. Sound like it will work out fine, but the surveyors ran into issues with finding and property makers in the neighborhood (long story there), and bad weather. Not enough time now for the notice period before the August meeting. So, no more progress until the end of September when the next meeting will be held.

Waiting (almost patiently),

David

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