New shop at the soon-to-be-mine house in the country

[Zach Dillinger]

Gents,

The wife and I have had it with city life, and we are moving back to the country neighborhood where we both grew up (about 6 miles from our current house). The new home is a beautiful 1900-built farmhouse. The issue: no shop space (the original barn burned down in the 1970s). A good friend of mine is the president of the Michigan Barn Preservation Network, and he just so happens to have a 16 x 20 timberframe granary with a loft, dissassembled and waiting to be rebuilt on my property. So, after I build some doors and windows, this will be my shop. I do have a question or two though.

Living in Michigan, I have to worry about frost heave, but I can't go to the expense of a full block / stone foundation, however cool that would be. I was thinking about doing treated 6x6 post piers with nailed on 2x10 foot, resting on crushed stone footing, making sure that the bottom of the footing ends up at 42" (just below the frost line in these parts). I would make the crushed stone footing 16" diameter, 8" deep, then backfill the post hole with gravel and concrete for stability. I plan to paint the posts with asphalt roofing tar to prevent pest problems. My plan is to leave the sills about 12" above ground level and brace those sills to the posts with treated 2x6 plates, lag screwed or nailed to the posts and sills. One pier in each corner. Would that be enough? Or would I need to put a pier in the middle of each sill? The sills are 6x8.

Given that this is currently agricultural property, I do not need a permit or inspection, so I am seeking the input of the "dudes in the know" on this forum. Does anyone see any issues? Comments or concerns? Encouragement? Yes, I will be taking lots of pictures of the raising, the door and window construction, and the tool museum / library that will be in the loft :)

Thanks,

Zach Dillinger

[Andy Fox]

I'm far from an expert on this stuff, but I think you'd want to use round tube forms to extend your concrete footing above ground by at least 6", and then use anchor bolts set in the concrete to attach the posts with post brackets. Any wood in the ground will rot eventually, and this keeps the wood out of the ground.

[Brian Tymchak]

I'm far from an expert on this stuff, but I think you'd want to use round tube forms to extend your concrete footing above ground by at least 6", and then use anchor bolts set in the concrete to attach the posts with post brackets. Any wood in the ground will rot eventually, and this keeps the wood out of the ground.

Definitely envious of your situation. Wish I could chuck it all and go hang out on a mountain somewhere...

I'm with Andy on this one, on both counts - far from an expert and agreeing that if you are going to dig the post holes to below frost line (which I agree whole-heartedly is required to keep your shop sitting straight after you build it), you might as well go all the way and fill those holes with concrete to above grade and build from there. I'm not enough of an engineer though to be able to say what size/how many piers you need to support the load of your shop, machines, snow, lumber, etc.

[Kevin Bourque]

I'm a building contractor, and I also live on a farm in the country. Heres what I'd do:

Dig a hole 42"deep X 24" in diameter( or square)....put 2 pieces of rebar in the hole and pour concrete into the hole about 1 foot thick.
Then take a 12" cardboard Sonotube and center it on top of the concrete.
Make sure it extends up through the ground at least 8" above grade ( all the Sonotubes tubes need to be level with each other ),
and then brace it with some 2x4's so it is plumb.
At this point you can backfill the hole to stabilize the Sonotube for pouring.
Fill the tubes with concrete making sure they are all level.
Make sure you imbed a weatherproof bracket into the concrete to secure the 2 X 12 sill beam.

Now, once this concrete dries ( a day or 3) nail 3 treated 2x12's together as the sill beam and
attach them on edge to the brackets you imbedded on top of the Sonotube piers. ( forget the 6x8 idea. They will sag eventually )
On top of the 2x12's nail a treated 2x6 plate that will help strengthen the corners and give you somewhere to nail the new building to.

For a 16 x 20 building as tall as yours, and subject to all the live load from heavy shop machinery and snow, I would place 3 piers on the 16' side, and 4 piers on the 20' side,
for a total of 10 piers.

Good luck.

[Thom Porterfield]

The above suggestion (Kevin's) is quite good, as far as it goes. But it doesn't take into account building loads, i.e.: if the pole spacing of the building is different than the spacing of the footings, undue loads may be imparted on the laminated beam (the 3-2x12s). It also doesn't take into account live loads of your equipment. A 16' span is pretty far when loaded up with cast iron shop machines and other accoutrements of a wood working shop. If it were mine, I would plan for an additional beam down the center of the floor (to limit floor joist span to 8 feet. I think it's advisable to make at least a tentative layout of your shop and place additional footings.

Unless, of course, you plan on a cast-in-place concrete slab on grade, in which case you need only worry about supporting loads from the timber frame. But again, were it mine, I'd want a really nice wooden floor above grade, that I could insulate.

[Zach Dillinger]

I should probably clarify. I have no woodworking machines and no intention to get any. This is a hand tool shop only (my business depends on this niche), the heaviest thing in my shop is my large workbench (350 pounds or so). Most of my wood storage will be elsewhere. However, snow load is obviously a huge concern and I'm a fan of overbuilding. I'm going to investigate some other granaries in the area and see what foundations they have. If it works for extremely heavy loads of grain, I imagine it will work for me.

Thanks Guys! I will let you know what I decide.

[Chris Damm]

I would do some checking on that no permit needed thing. I have had "agricultural property" and I was required to get permits for just about everything I built. Even properties out in the boondocks have been zoned!

[Zach Dillinger]

Chris, you're right to be concerned, but I actually used to serve on the Planning Commission for my county, which has zoning jurisdiction over this property. Agricultural properties over a given acreage are exempt from building permits / inspections for outbuildings. So I'm good :)

[Bob Winkler]

I did a similar thing when I built my shop 3 years ago. Saved a lot of money over poured foundation. These are the guys who did my shell, and here is their explanation of a "posted" foundation:
http://www.thebarnyardstore.com/custom-garages/foundation-options/39-posted-foundations

6x6 posts, every 8 feet, sitting on a concrete "pill" set below the frost line. If it works in New England, it should work in Michigan. I haven't noticed any issue to date.

[Bill Edwards(2)]

Gents,

The wife and I have had it with city life, and we are moving back to the country neighborhood where we both grew up (about 6 miles from our current house).


Zach,

Which direction from town? (N,S,E,W)

[Zach Dillinger]

Zach,

Which direction from town? (N,S,E,W)

East. I'm curious why you ask :)

[Bill Edwards(2)]

East. I'm curious why you ask :)


East? Like M50 towards Eaton Rapids?

I lived and worked in Charlotte for just over 5 years. I always liked the area.

[Zach Dillinger]

Bill, not quite to Eaton Rapids. If you imagine a straight line heading East out of Charlotte, and a straight line running South out of Potterville, the new house would be pretty darn close to the intersection of those lines.

I like the area as well. A nice mix of "city" (theater, shopping, etc.) with a large dose of country peace. Easy to get pretty much anywhere from here.

[phil harold]

how about just a simple trench footing?
Trench the perimeter, form the top level and place your concrete

[Chris Damm]

That's good Zach. Where I was I had 80 acres and they tried to rezone it residential on me. What a pain that was!

[Kent A Bathurst]

Bill, not quite to Eaton Rapids. If you imagine a straight line heading East out of Charlotte, and a straight line running South out of Potterville, the new house would be pretty darn close to the intersection of those lines.

I like the area as well. A nice mix of "city" (theater, shopping, etc.) with a large dose of country peace. Easy to get pretty much anywhere from here.

Not to mention the annual Gizzard Fest in Potterville..........you forgot to mention that.

Lived for 12 years on S River @ Hamlin in Eaton Rapids. Cross S River, down the walkway, across the footbridge, and I was in Island Park. Cross one more footbridge, and I was at the hardware store.

[ray hampton]

keeping the posts dry will be hard to do if the rain or snow get blow in under the building

[Kevin Bourque]

The above suggestion (Kevin's) is quite good, as far as it goes. But it doesn't take into account building loads, i.e.: if the pole spacing of the building is different than the spacing of the footings, undue loads may be imparted on the laminated beam (the 3-2x12s). It also doesn't take into account live loads of your equipment. A 16' span is pretty far when loaded up with cast iron shop machines and other accoutrements of a wood working shop. If it were mine, I would plan for an additional beam down the center of the floor (to limit floor joist span to 8 feet. I think it's advisable to make at least a tentative layout of your shop and place additional footings.

Unless, of course, you plan on a cast-in-place concrete slab on grade, in which case you need only worry about supporting loads from the timber frame. But again, were it mine, I'd want a really nice wooden floor above grade, that I could insulate.


I neglected to mention that a center beam ( structural steel) should go down the middle of the building to support the floor load and any bearing wall loads.

[Zach Dillinger]

Well, I took delivery of the frame today. Got some pics of it and the site (gotta love the view!). Still working on the foundation, but the soil is very sandy and I'm leaning towards putting it up on skids. The long beams in the last photo are the new sills (the current sills have some rot and I want to replace them).

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