Advice Needed - Generator Shed Build

[veggie]

Hi All,

Building construction is not my strong point so I'm fishing for a few suggestions.

Scenario:
I want to build a wood frame shed along the side of my garage to house a generator, solar controller, and a small battery bank.
On the roof of the structure will be approx 900 watts of solar panels.
The approximate size of the structure will be 5ft wide X 12 ft. long.

Obstacle:
This is a prime place to locate the "power shed" but the utilities to my house run under the ground in this area.
(Natural Gas line, Water Line, and Sewer line)
For this reason I am reluctant to drill holes and sink concrete piles.
Here in Canada frost movement can be an issue and the frost line can penetrate 5 ft.

So... my question is what options do I have as a base for the shed?
- One option is to pour a "slab on gravel" concrete pad. This pad could float with any frost heaves. Movement would be minimal.
- Another option is to build a wood beam foundation mounted on 1ft X 1ft concrete pads at each corner and in the mid points of the base.
This building is not expected to house the Listeorid so I am not too concerned about vertical vibration/thumping.

Has anyone done anything similar? or maybe have a different approach ?

Cheers,
Veggie

[dieselgman]

Your narrow 5' width makes this a pretty easy building to mount on a skid. I have built small enclosures like this with steel frames, no reason it couldn't be easily done with wood as well. Anchoring to the ground would be the issue for a very light structure and wind resistance etc.. In Kansas we have locator services that will mark fairly closely any underground piping or wiring... maybe you could do the same there for installing some simple screw anchor/pilings?

dieselgman

[Thob]

I'm thinking about a similar situation for my next place.

You can also use foam insulation just below the surface of the earth to insulate the ground so it doesn't freeze.  It has to extend several feet out from the building.

My thinking is to build the building out of stuff that won't burn.  I worry about the contents (generator, fuel, batteries, inverter) being fire hazards, and don't want the house to burn down if things go terribly wrong.  For me that means a steel structure with steel siding and roof.  In addition, I plan to put the power shed about 50 feet from the house, but then I'll have the room to do so.  If you must build it out of wood, at least line the inside with sheetrock.

In my case, my next place is 20 minutes from the fire department.  It'll be good to know that when seconds count, help is only an hour away!

My only other suggestion is to make it bigger than you think you need.  Five feet wide sounds a little cramped to me.

[BruceM]

+1 for Thob's suggestion of bigger.  In the history of man, no man has every complained that their engine shed (or shop) is too big.  Enough room to store parts, tools, fuel, oil etc. makes engine service way more fun.  

Getting the pipes marked might be your best solution...after that Gary's moveable shed or Thob's insulated earth suggestions sound good.

[veggie]

Thanks guys,

My garage is detached from the house and the plan is to build this unit along side the garage near my greenhouse.
I suppose I can push the width to 7 or 8'. After that it will extend into the lawn area and look out of place.
Ok...So the size can be 8 X 10ft long.

It is a very sheltered area so I'm not concerned about winds.
The Garage and shed are about 18 ft. from the house and the intended insulation is fire retardant rock wool (Roxul).

That leaves the base...
dieselgman's idea of a steel skid is interesting, I do have access to a place where I could get a steel skid built. That may provide the mass to simply be able to
set the building on a gravel pad and have done with it. Getting a 1000lb steel skid over my fence and placed in the yard may be an issue, but it is possible.
My wood frame structure could then be built (and bolted) onto the steel skid. The idea is to have a pretty looking garden shed with nice shingles and siding so that it looks good, but diguises the true raw diesel power hidden inside. Must keep the aesthetics in order  

Perhaps a 6"X6" wood frame base would work the same way. I have to evaluate that.

Anyone else done this?   Ideas?

Thanks so far,
Veggie

[vdubnut62]

duplicate post

[vdubnut62]

My situation is so different here in TN. I have 4" x 6" treated posts 24"-30" in the ground set in concrete. The frost line here is probably 12"- 18" at the most, closer to 12".  Power, water, and hydronic (is that the correct term?) is all underground.
The structure is 16' x24' with a 12 foot ceiling. I haven't decided what to cover the inside with, but the outside will be vinyl to match the 'Ol tarpaper shack. There will be a 'roid, a Xingdong 1115,  a Tarm woodboiler and a 500 gallon propane tank sitting on end converted to hot water storage. That's why I have a 12 foot ceiling!  It's prob 60-70 feet from the house.
See, I am no help at all.
Ron.

Don't know how I managed to quote myself?

[quinnbrian]

I've lived off grid for about 5 years now.I have  a similar building as the one you are looking to build. My power supply/charge system, batteries ,generator all live in the same small addition on the side of one of my building. I think it's about 8x10ish....I live in Ontario Canada...and any building over 96 square feet needs a building permit, in my area . Anyways if you live in a colder climate as in Canada, I would highly suggest that you insulate the floor(some Styrofoam under the concrete floor)  and insulate the wall and floor(if the floor is made of plywood...wood etc.)
My setup has my SR2 inside the building, with the gen head on the outside( generator 1/2 through the wall) The heat from the SR2 heats the building, while drawing fresh air in from outside , from around the gen head.The gen head has a covered /roof assembly over it. Batteries stay warmer, fuel stays warmer...etc. Keeps the room dry! which is very important to me.....batteries...$3000.00.....inverter/charger.....$4000.00...solar charger.....etc.
Cheers
Brian

[vdubnut62]

Frost line is the depth to which the soil freezes.....
Ron.

[veggie]

All good ideas gentlemen, thanks

Insulating the floor is a must. I had planned to run some PEX tubing under the floor (but above the floor insulation) and use one of my evacuated tube H20 solar panels to help keep the place warmed.
Engine coolant heat could also be exchanged into that loop using my flat plate exchanger when the generator is running.
Right now, my engine/gen is in one place.....battery bank in another....., and solar panels 30 ft. away.
The objective is to pull all of this equipment into the same small building.

veggie

[BruceM]

Veggie, we did just that same consolidation you're doing for my new neighbor's off grid homestead.  Engine generator/air compressor room, with the back room for the solar battery bank,  which also powers his Verizon home phone connect which is around the bend to get a good line of sight to the tower 5.5 miles away.  The solar panels (1250 watts) are next tho the shed on seasonal tilting ground racks that I also designed.  Plenty of room so no need for roof mounting headaches.

[mike90045]

I built 2 sheds, one for inverter, solar gear and batteries.  About 4 ' away was generator shed for the listeroid.  10" thick slab, 2 layers of rebar.

My thought was, if one system burned, the other system may survive and carry through for a couple days.

[LowGear]

A slab of concrete 4' X 5' would weigh around 2000 pounds - guessing.  Would it sink over the years as the frost came and went?  Those ~50 pound premix bags would be pretty easy to get anywhere and you could just hand mix it right in the form.  Throw in the re-bar and anchor bolts as needed and voila; you're on the couch for only a week with a sore back.  Maybe I've been hanging out in a third world too long?

[LowGear]

If we're going to get crazy with tool overhead then just hire a pump truck to get it over the house when concrete truck shows up with your yard or meter of concrete.  But really, wouldn't a slab 1'X5'X4' be enough to stabilize the engine?

I ask because I'm looking to set up a Witte in the next year.  They run pretty smooth so I'm thinking ax hewned beams would be an interesting contrast to the retro looking Witte.

Casey

[Tom]

An electric mixer was used for the slab and block in our generator shed. It has a 6" slab with a 18" perimeter footing. The generator is mounted on a 16 x 18 x 60" block set into the floor. Lots of rebar was used and a 20 lb LP tank was set into the floor for an under ground muffler and exhaust. With 2 people working the mixer and one working the concrete the job went quick. Mixed 1 shovel of cement to 5 of sand / gravel mix and there are still no cracks.