Advise sought on pier construction....

[NM_Shooter]

Hi... what a nice site!  My first of probably many posts.

I am going to be constructing a small cabin (maybe based on the small house plans?) in Northern New Mexico at a fairly high elevation:  10k feet.  I have absolutely found Eden, but with all things like this, the access sucks.  I can drive my 12' utility trailer next to where I will build, but I am 2.5 hours from the closest lumber yard.  It is 60 minutes just on a nasty rock and mud road.  Sounds perfect to me too.  

I have some experience framing and with general contracting as I built my own addition on my house, as well as two barns.  Here is a link to my addition pictures, I have not updated in two years, but it is 99% done (never 100%, right?)
http://mywebpages.comcast.net/a.wirtz12/housebuild/Wirtz_Addition.html

So... I have never built on piers.  Stemwalls only.  So I am a bit concerned about some of the details, especially since I don't want to tote up anything longer than 12 feet.  Because of the snow load, the whole thing has to be bomb proof.

I want to build a 16X24 little house, with a loft.  I may stretch the wall studs to 9' just to give the loft a bit more headroom.  Plans are to run a 8' porch along the long side of the structure, so the footprint will actually be 24X24.  I'll have to brace the heck out of the porch roof, as 8 to 10 feet of snow is not uncommon.  Since the main roof will be dumping snow on the porch roof, I sort of get a double whammy.  (Any thoughts on this?)

I'm guessing that the piers will be spaced on a 12'X8' spacing, so I will have three rows of four piers.  I kind of like the idea of having center support for the cabin, and a center post to help out with the loft weight.

I'm thinking of using cinder block pilasters stacked on site and filled with concrete as the piers.

So.. here is one of my questions.  If I use 12' long beams (Probably 2X10), how do these splice together in the middle such that they are tied together, yet the mechanical fastener is out of the way from the Simson joist hangers?

Cripes.  I thought I knew how to do this sort of thing.  I'm not even in the air yet and I've got questions.  

Thanks,

-f-

[glenn kangiser]

Here is some info on the beam.  The plans have info in them also.

http://www.countryplans.com/builtupbeam.html

The joints need to come out over a post  and stagger them as much as possible .

Have you thought about something like a Salt Box design so the house doesn't dump onto the porch - or move ridge over and have the porch under the roof span as if it was a 24' wide house.

Just ideas.

[desdawg]

You may have to flex some on the 12' lumber length limitation to accomplish what Glenn suggested. A steeper roof with metal roofing would shed snow and I see that solution quite often. What have some of your neighbors done if you have any up there?

[NM_Shooter]

Thanks for the assistance!  

I had not considered a salt box, or extension of the full roofline to cover the porch.  That is a great idea.  

I do have some "neighbors" but this is a recreational club and no one lives there full time.  Most of the cabins are very small, the largest to date is 16X20, no porch.  One of the cabins is about 10X12 with a loft!  I would build smaller, but I need to house 4 to 6 persons in this.  

If I build a 16X24 with a full porch, this will be the mansion of the property.  I really need to have a nice porch... it is more important to me than the inside of the cabin  

I started to sketch an elevation or two last night using Glenn's idea, and I think it might work.  My problem with long lumber is that because of the creek crossings to get up here, I was afraid that I would be dragging boards on the ground as I cross these dips.  I guess I could put the longer lumber on top of the stacks of OSB, or build a small frame for my trailer that would elevate the longer stuff and keep it off the road.  I can cheat by pushing the longer lumber forward on the trailer as well.

It looks as if I build using a 24' roof chord, then with 16' stock for the roofing beam (top chord?) that will still give me a 7-12 pitch, which should shed snow pretty well.  

Thanks,

Frank

Still curious about the interference with the simpson ties on the joist hangers.  Or do I just stagger the floor joists so that I put in an extra one on the end where I start and shift the flooring so that the 12' pier does not have a 12' tie right by it?

Am I making more work for myself than necessary with the Pilaster piers?  How well do 6X6 pressure treated posts hold up if cemented directly into the ground?

Do the plans from this site show different methods for foundation support using piers?

Thanks again,

-f-

[glenn kangiser]

Most of the methods of floor construction in the plans run the joists over the beams so there is no interference of hangers - beams and floor joists.  Some of the small designs are cantilevered designs using lighter members but still having stiff floors.

Even if using hangers I think you could work it out - notch the end of the joist - angle the hanger -  bolts to the side - nailed brackets etc.

Sometimes the piers work out better with gravel or soil cement around them and a paver or poured base in the bottom.  Conditions vary.  There is special heavy treated foundation grade wood.  The plans have several foundation methods depending on the ones you have.  

Here is post and pier info also.

http://countryplans.com/foundation/index.html

[MountainDon]

Greetings Frank/NM_Shooter. I too am in NM (home in Rio Rancho, cabin property in the Jemez, just south of the Valle Caldera, several miles down a bumpy forest road.) 8800 ft. elevation. Where's your property, if I may ask?

As for building on piers my closest neighbor built a 18 x 34 foot cabin on piers; 3 rows of them, 3 beams. There are many more a few miles away. Sometimes they've used "sonotubes", those cardboard things that you set in place and then fill with concrete and re-bar. My pan is similar to your proposal; poured concrete footing, with concrete blocks dry stacked to above grade. Then filled with concrete and some rebar. From the top of the concrete blocks I intend to use PT 6x6 or 4x6 posts using Simpson post bases and post to beam brackets.

I'll be using built-up beams as Glenn pointed out. 6x12 with posts at 8 foot spacing, with 1/2 spacer material to allow fitting to the Simpson hardware. The joints don't necessarily have to fall over a post. But the three 2x used to make a 6x must have their joints no closer than 4 feet to each other. You may have to play around a bit to get lengths that will work with your post spacing.

Metal roofing is the hot thing for cold snow climate. Snow slides off real easy, even on a 4:1 pitch. Go steeper pitch and there should be no problems at all. Watch how you place the doors, you don't want a couple feet of snow sliding down on your head.  

I would reconsider that porch roof. I've seen a similar thing in the Jemez and the snow does build up on it. Because it's metal to does slide off fairly well, but sometimes there's a few feet just sitting there.

I extended the tongue on my utility trailer to allow carrying longer lumber. It's only an 8 footer, with 18" high metal sides. I can carry 16 footers on top of the box IF there's enough of them and loaded and strapped for maximum stiffness.

[desdawg]

Hey Frank, by the way Welcome! I am next door in AZ.

[NM_Shooter]

Thanks to all...

I live in Corrales, but this cabin is going to be up near Chama.  Potential for lots of snow, although I am placing this in a sunny southern exposure, and out from the trees a bit in the wind.  I looked around near the Caldera for land too... spend a lot of time up and down FR10 and the surrounding neighborhoods.

I think I am going to follow Glenn's advise and make the footprint of this thing be 24'X24', with a heated area of 16X24, and an 8X24 porch.  I'll cover the whole thing with a 7:12 pitch which should leave enough tails on 16' rafters to drop the snow away from the cabin a bit.  

Glenn also suggested a cantilevered floor structure, which I understand how it would work with a 16' span.  Going to a 24' span confuses me a bit, as now it seems I would be using three beams, which would also mean that I would have to stagger the floor joists where the main cabin and porch joists meet.  This would mean that I would have to shift the layout of the floor plywood... right? Or maybe I should use Trex for the porch.....

-f-

[glenn-k]

I personally hate Trex but some people don't.  

You could build the cabin per Johns plans except the roof and the wall that is on the inside of the porch.  Extend it up the amount necessary to meet the rafters and make a seat for a birdsmouth on the rafter then continue to another one at the porch wall.  Cabin deiling joists could rest on a ribbon inlet into the wall like semi balloon framing.

If the porch is going to be exposed to the weather it could be attached to the side of the font cabin wall with a ledger and dropped the standard 1 1/2 inches like most do, but the porch post and beams extended the height desired to meet the rafters and if a ceiling is used it can be standard height or extend the same as the interior ceiling -- it wouldn't be necessary though.

The porch would then use one more row of piers.

[MountainDon]

Frank, this is a wee bit off your topic, but if you're like me you always wonder what the weather is like up there in your mountains. Here's a link to a website that gives you access to remote weather station readings all over the USA.
http://www.met.utah.edu/droman/states/NM_state_frame.html

and this one should be the station closest to your site
http://www.met.utah.edu/cgi-bin/droman/meso_base.cgi?stn=CHMN5

[NM_Shooter]

Well heck. 

I talked to a contractor about the rim joist construction being 3 pcs of 2X12 seperated by 1/2" ply, and he said that for a 12' span form pier to pier I would have to have 4 pcs of  2X12s to support the load!!!!.  What the heck?!?!?  Should I consider placing my piers on 6' centers?  Seems like a lot of support....How in the world would you pin all of that together?

My current idea is a 16X32 footprint.  The first floor of the cabin is 16X24.  There will be a 16X12 covered porch out front.  There is a loft over the back 12' of the cabin, with the loft floor at 7'8" above the first floor (actually using 2X8s with the bottom of the joist at 7', spanning 16' with a center support halfway).  Pony walls above the loft floor(no recessed ledger) support a 6-12 pitch single gable sort of roof.  There will also be a loft in the area above the porch for another sleeping area. 

I can't imagine that I need that much beam strength.  Any comments?

I am worried that my "little house" plans may not provide the detail I need.  Is there a service associated with this forum that can turn out modified plans for me?

[glenn kangiser]

I think everything is in John's plans but for more, John has    http://www.planhelp.com/

A membership service and I don't know what all he offers there.

[John Raabe]

The design of a beam and pier foundation is not as standardized as a perimeter concrete stemwall, which is built just about the same all over the country.

You have to do a load trace of the entire structure including snow, wind, floor and wall loads. At the bottom of your support walls the size of the beam and the spacing of the piers is one final tradeoff. A bigger beam can span further between fewer piers in hard well supported soil or where frost requires deep piers. A smaller beam with more piers would be better for sandy soils or shorter piers. Either one has to support those accumulated loads, of course.

You should NOT try to use the Little House foundation for a larger 16' building. I have a 16' wide pier and beam foundation in the Victoria cottage plans and have placed the beams directly under the walls. This is a better layout for the heavier loads of the loft and wider floors.

Post and pier foundation plans can be extended in length (assuming the same loads) but not widened. To do that you should get local help with the new design.

PlanHelp can help with details and layout templates for interior changes but relies on the foundation plans of the paper plans.