Contemplating 24'x64' cabin

[markert2523]

Howdy folks,

I survived building the 12x16 modern manshed and learned a lot along the way.  I'm in the daydreaming stage of planning a cabin build in a rural setting.  Not to get into the land situation too much, but I belong to a club that has about a hundred acres in a remote setting with a central lodge and 20 or so fairly rustic cabins.  The club is on a beautiful creek and has a water system that draws from the creek and pumps to a large water tank for distribution.  Electric is not difficult.  I would have to put in my own septic. 

I want to build a joint cabin along with another family that currently shares the lodge with me and a few other families.  I'm thinking about using this plan but eliminating the central wall that divides the "duplex".



I'm planning to build on concrete piers, probably 12" diameter sonotubes, and using premanufactured trusses.  I guess I'm a little nervous to build such a large structure on piers so I'm planning to put 4 rows of piers lengthwise with a little over 7 feet between the rows.  Each row of piers would have a pier spacing of about 6 feet (I'm guessing).  The floor joists would be 24' 2x8's 16" oc with the ends cantilevered a foot on each side.  The beams would be 2x12 sandwich beams built in 16' sections.

We would like to have a sleeping porch run along almost the entire back side.  We only need one washer/dryer so one of the washer/dryer areas on the plan would be built out as a powder room accessible from the sleeping porch.  The front door would be changed to resemble more of a single family dwelling and there would be a deck in front.  Would be nice to use attic trusses so we could put a sleeping loft in one of the bedrooms on each end.

I want to space it out over a year or so.  Thinking of hiring out septic and water supply first.  Then hire out the drilling/pouring of the piers.  Put in the floor joist and deck myself.  Hire out the framing/sheathing/trusses/metal roof/electric service/plumbing/ac and heat.  I would finish the interior and install the kitchen.  The interior electric wiring would probably be a joint effort between me and my electrician.

Many questions:

Does the number of piers sound sufficient?

Can I use the simpson joist holder I used in the manshed or do I need a beefier way to connect the beams to the piers?  I always worry about the beams tilting and failing.

If I did the majority of the interior build out myself and keep it simple, could I do the basic structure and kitchen for $50/SF (about 80K total)?

I'm no carpenter but I think I can get it done.  Here is a link to the manshed I built so you know the limits of my past building experience.
http://countryplans.com/smf/index.php?topic=7077.0


Any comments appreciated.

[MountainDon]

With the size of the building and the potential for some mighty high wind loads on that long side I would strongly recommend staying away from piers unless you get an engineer to okay it. Perhaps concrete or masonry piers on a full perimeter poured steel reinforced concrete footing would work as well as what is done with some raised floor type of construction. A single row of the same piers down the center, also on a full length footing would permit using lumber floor joists if you don't want to go with floor trusses.

The concrete/masonry piers would have to be tied well into the continuous poured footing. That way the whole thing works as a unit. Individual piers on individual piers is not nearly as strong, not nearly as able to withstand winds and/or earth movement.

[Don_P]

I'd do a slab or crawlspace myself.

No cantilever if you plan to attach a floor to it. If there is a floor surface, a porch or deck, hooked to a ledger, bolted to the floor rim or girder... that rim/ledger connection needs to happen over support, the piers, not hanging by nails on a cantilever. This automatically triggers another set of footings and piers under that side of the porch or deck and self supporting framing, braces all around.

[markert2523]

Thanks for the replies.

MtnDon--I think you're right.  I guess I had that gut feeling but I wasn't listening to my gut!  We get some good winds here in OK land and we also had a 5.6 earthquake recently.

Don_P--I would really like to avoid a slab.  When you say crawlspace, I assume you mean a perimeter footing and block or concrete raised foundation?  I guess that would be doable.  And maybe a center footing/block wall to support the floor joists as MtnDon suggests.

Any eyeball guesstimates on costs?

[markert2523]

I guess if I had a block foundation I still could use sonotube piers to make the back sleeping porch and the front deck.

[nysono]

Im into my camp for about 20K (24 x 32) with no hired labor.  Full basement and half loft.

http://countryplans.com/smf/index.php?topic=10852.0

[Squirl]

Since you live in windy country I would double check the AWC wind and seismic guide.  There are length to width ratios for buildings depending on the wind load and construction type.  Over 2.5:1 I think violates some, but I haven't read it in a few months.  It is free at the website.

Edit: My memory this was more dependent on type and method of sheathing.

[JRR]

I see nothing wrong with the concept of piers.  (Might not be the best choice for "hiding" from storms.)  If the piers are stout enough, (reinforced concrete, or masonry) ... some landing on footings, perhaps some extending deep without footings ... and there are enough of them, any seismic or wind conditions can be met.... or, at least, so I would think.   I'm not a building/structural engineer ... and would hire one in a hearbeat for a quick analysis.

[markert2523]

Nysono, how do your floor I joists attach to the block wall.  Do they just nail into the sill?  I see there is an osb face around the perimeter.  I guess that and the floor deck keep them in place?  Also were they trimmable or did you have to get the length spot on when ordering?

Thanks

[nysono]

Nysono, how do your floor I joists attach to the block wall.  Do they just nail into the sill?  I see there is an osb face around the perimeter.  I guess that and the floor deck keep them in place?  Also were they trimmable or did you have to get the length spot on when ordering?

Thanks

I joists are nailed to the sill plate and center beam and rim board also is nailed to the sill plate and I joists.  Yes they are easily trimmable.