My 30' x 40' tractor garage

[eepete]

With the pad poured, it's time to do the electrical. This took way to long, and being a one man band didn't help. I brought three circuits from the house. A 15 amp light circuit that is on the whole house generator, a 20 amp outlet circuit also on the generator, and a 100 amp sub panel circuit that comes off of the breaker box _before_ the transfer switch (so it is not on the generator).

The 1st picture shows the 3" conduit from the house going into a 24" square junction box. You can see the big #2 wires going down to the breaker box. A pricing quirk at the big box stores had the #2 wire cheaper than the #4 wire, so I went with #2 including the ground. I love overkill. You can also see a disconnect switch for the two circuits off the generator just to the right of the breaker panel box. The 2' box and disconnect is where working with my buddy the electrician helped. I'm sure that most inspectors could help too, I've had ours out for a consultation when I'm at a point like this and it's been very helpful. No point in doing something twice when you could have asked and got it right the 1st time.

The 2nd picture is a close up the area above the big honking 2' box. Some pipe went on the outside of the poles, some on the inside. I probably could have heated and bent the conduit instead of using the pre-formed pieces, but it was easy to use the pre-formed and helped me in one man band mode. The big 2.5" goes to the other side of the garage both to get power to the future air compressor in the inverter shed, and as a general way to get "stuff" over to the other side for any future escapades.

The 3rd shot shows the switches for the lights at the door. There is also a box for low voltage for a phone and door switch for security. You can see a pipe going down by the hinge of the door- this is for an outside light on a motion detector.
The four switches: The 1st switch goes to 2 60 watt incandescent flood light bulbs. This lets me get a little light so I can see to get something from the garage. The 2nd switch goes to 7 24 watt compact fluorescent flood light bulbs for when I really need to light the place up. Since they take a while to get to full brightness (more time if it's cold), I will only use these if I'm going to be in the building for a while. All compact fluorescents are like well pumps. The may run forever but they only start so many times. So being able to choose between the cheap incandescent and the fluorescents is a win. The next two switches are outside flood lights, a set on each side of the building.

The 4th shot is a close up of the are above the switches, showing the two drops to the boxes. Yes, I could have just used one drop and then connected the boxes. There are many ways to run the conduit. I suspect if I did it for a living it would be completely different. The best feature of all this conduit and wiring? It works

Why conduit over just stapling romex to the wood? Well, I do like overkill. I also liked the physical protection I get. And if I have to add something else after everything is buttoned up I can pull more wire in conduit. Finally, and this is very fuzzy and subjective, I like the 10,000 volt insulation of the conduit in case the building gets hit by lightning. Can't prove it would work, but it can't hurt.
BTW, the rebar in the pad has a wire that comes up and ties to the AC ground.

 

[eepete]

Next step is to prep for insulation. I'm using the spray foam (iscyonene (sp?)). Now I could just spray it on the metal, and it would be just fine. But if you had to replace a piece of siding, the foam would come out with it. So I decided to put plastic up against the bottom run of metal siding (the wainscoting) since that's what I'd be more likely to run into. Then I decided to make the building more sustainable and do it all. That way, in 30 years (I wish) when I exit horizontally, the next user can replace or upgrade the building siding and the insulation will stay put. It's green two ways. (1) Longer building life and the metal siding is very recyclable, and (2) if the next owner looks at changing the siding out and sees/learns of the plastic, it's one less reason not to by the place. My nieces and nephews will thank me some day as they blow our money. I like any green project as long as it's green two ways. And the original "you can fix it without bunging up the insulation" is good stuff too.

The 1st picture shows a prepped area. At 1st, I tried a vertical sheet. but I had to put in blocks of wood to give the insulation something to grab on to. So then I went horizontal so that all the horizontal purlins would be exposed and the foam would stick to it. I put some extra screws in the wood to help the insulation stay put. Behind the big 2' electrical box, I put hard foam insulation, same for the breaker panel and a few other areas that would be blocked and hard to get the foam into.

The next picture shows the area between the garage doors. On the left, you can see the water line I ran in the 3" PVC from the house for a hose bib. You can also see the 2x6 I added between the Morton post to help put up a wood wall cover later. I had to add these all around the building. You can see a copper pipe for compressed air running down that added wall stud. Then you see one of 4 outlets. I already mentioned one on the generator, there are 3 more 20 amp outlets in the building. Finally, one of the lights are shown. Simple, same bulb I use everywhere for outside lights. Note also that I covered up the soffit vent so that the foam would not get UV exposure from the outside. The foam degrades quickly when exposed to UV.

The 3rd picture shows the south east corner of the garage. I added blocking for shelf brackets. This is where a lot of implements will be stored, many on dollies. Having a shelf at the 6' level, above the implements, give me more storage room. Again the soffit vent is blocked and you can see the 3rd set of inside flood lights.

 

[eepete]

With the floor covered and everything masked, it's insulation time!

Three shots of blowing in the insulation.

 

[eepete]

Next step was to put up the wood walls. The first two feet are pressure treated 1/2" plywood at the bottom. Then I put in either 7/16 OSB or 3/4 plywood above that (next 4' of height). I used the 3/4 plywood where I thought I might be attaching things to the wall such as hooks, holders, etc. I used 7/16 where I would have shelves. I was originally going to use a 3/8 panel, but the 7/16 was only a buck more a sheet. With 4' between mounting points, that would have been a disaster. Don't use anything smaller than 7/16. Above that, for the top 4', was all 7/16 OSB. All this went to a height of 10', the same as the tallest door. This provides both physical and UV protection.

 

[eepete]

Paint time!

The exposed insulation needed to be painted so that it would not degrade. So I painted the insulation and walls white. The white really helps with the light in the place. Yes, it will get dirty and dingy over the years but it's a garage, get over it .

The last shot shows the entrance and north wall. A little paint, a little wood, and things are starting to look pretty good. I also sealed the concrete floor since we finally had a day with temperatures and humidities in the right range.

 

[eepete]

Here are some stitched shots of the interior. Not a good stitch, but gives some idea of what it's like.

 

[eepete]

Here's a controversial one. I grounded the outside of the building into a ground rod. I used 1/2" stainless steel strap. It is connected to the ground rod with a stainless hose clamp. This is better than 90% of the buildings with no grounding where you take your chances, and not as good as "real" lightning rods into big wires going to lots of ground rods. I've seen the results of lighting hits on buildings with all my firefighter work. This lets lightning find ground without having to make some annoying couple foot arc and all the consequences thereof.

DO NOT DO THIS. There's my disclaimer.

Part of why I have all my wiring in conduit is that the conduit provides about 10 Kilovolts of insulation. Since that's all on the inside of metal box, if I provide a way on the outside for the charge to go to ground, I have a better chance of not having the strike get into my electrical. The outside lights are also fully insulated from the shell. Again, no guarantees, DON'T DO THIS, I'm just trying to improve the odds if I have an average strike. I'm pulling rank with my electrical engineering experience and saying don't try this at home. Do what I say, not what I do. Betcha I still get flamed on this one...

 

[Mousefield]

Well done, well documented and great pictures. :thumbsup: When can you come and build me one of these?

 

[eepete]

I put yard drains in by the aprons. This is where I had the 6" cut during grading. The drains are 2" lower than the ends of the aprons. When I do the final grading and landscaping, this will give the water a way to get away from the building where I've cut out a low spot. This is a 3" PVC smooth drain pipe with the 1/4" per foot drop. Of course, this was all in place before the pads were poured.
The other three sides of the building will have a grade so that the water drains away from the building. That's where the Tnt and Boxblade do their thing. This is why on the south side during initial grading I took a 6 foot cut beyond the building perimeter. I can use the box blade to make a 12' 'V' for drainage that works into the grade. Nothing to clog, mow to maintain.

 

[flusher]

Here are some stitched shots of the interior. Not a good stitch, but gives some idea of what it's like.

Excellent job. Thanks for the details and photos.

Just a suggestion:
Your images take too long to load.
The Microsoft Power Toys website has a utility for Windows Explorer and Windows Libraries (in Windows 7) called "Image Resizer" that allows you to easily change the size of an image.

Microsoft PowerToys for Windows XP

I think you'll like it.