32 x 36 in S.E. Oklahoma need your help

Started by Dallas2build, March 06, 2010, 08:22:15 PM

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Dallas2build

I am entering the final planning stages of my 32' x 36' cabin to be built in southeastern Oklahoma.  I have been reading here for a while and really have enjoyed watching the projects unfold before my eyes.  I have really come to appreciate the great advice that is available here from the professionals and the novice builders alike.

20+ acres in southeastern Oklahoma's Kiamichi mountains accessable to bring in small equipment like a bobcat, tractor, etc..., but a concrete truck is out of the question as the road is rough, steep in places and I would have to cut more trees than I want to.  No electricity, no water, no sewer, no building code, no inspectors, etc...  I'm about 35 miles from the nearest paved road or house.

I've chosen 32' x 36' as I want to build something that will accomidate 6 people comfortably.  1.5 story, 10' walls, cathedral style ceiling, on pier and beam, 2x6 framed on 24" centers.  Wood stove for heat, propane for water heater, stove and refridgerator.  I have a 500 gal water tank already and plan to build a 12 volt pressurized water system.  Solar panels may be included at some point, but that's my dad's project as he is an electrician by trade.  

My skill level.  My dad is an electrician, my grandaddy was a plumber, my uncle is a plumber, another uncle does HVAC so I started dragging wire and vent pipe through attics and pipe under houses by the time I was 5.  I've remodeled several houses myself and I'm the guy that all my friends call when they need something fixed.  When it comes to framing and new construction planning I'm clueless.  Also, I love overkill.  If I need to use a 4x4 I'd rather use an 8x8.

So, my first question is about the piers and beam foundation.  My building site is sloped towards the creek and the front piers will only need be about 16" tall.  The piers along the backside will be much taller, nearer the 5' mark.  Other than sono tubes full of concrete and conctrete blocks what will can I do for solid piers considering the height of the back ones?  My major concerns are obviously termites and rotting.  Mountain Don and I have already talked and eliminated some creosote bridge timbers I had.  Is there any form of wooden post and way to use it that is resistant to termits and rot.

Thanks to everyone in advance for all the advice to come.

Thanks Dallas

Redoverfarm

Dallas IMO I would probably use flue liners which are 16X16X7-5/8".  There is minimal effort to drystack and backfill with concrete and rebar.  Just figure out the proper top elevation of your footings to use the 7-5/8" increments to attain the desired level in heigth.  The last block you could incorporate a beam bracket like Simpson embedded in the concrete with a lateral brace to the connector and tied to the verticle rebar as well.  The footings should also be reinforced with rebar and some tied to verticle postion out of the footings to the center of the block cavity.   This method does not required alot of concrete except for the footings (24"X24") and the majority can be mixed in a mortar box or wheel borrow. 



Dallas2build

Ok, forgive my ignorance but the only flu liners I'm familiar with are clay.  Will clay hold up to the elements like that year after year?  I have some old clay pots and they are fragile. ???

Redoverfarm

My error Dallas I meant Flue Block.  I was trying to get the point across about the cavity in the flue block.  I was thinking and my fingers were not transfering my thoughts very well.   d*.  With that cleared up did you understand my method. 

Redoverfarm

Dallas these are what I was referring to.  You can get them in an asortment of sizes. The original post I stated that they were 16"sq but in actuallity they are 17"

http://whiteblockcompany.com/shapesheet_07chimneyblock.php


ScottA

I'd consider buying some 8" steel pipe and filling it with concrete for the high piers.

Dallas2build

Red, after checking out the link I think the blocks would be solid and fairly easy to work with so I like that.  My biggest concern is the precise nature necessary when using the blocks.  Unlike wooden post I can't set them and then cut them all off level.  Also, at that height would they still be stable since they aren't a solid object and instead stacked?

Scott, after giving the metal post some thought, which I really like, I have one major question.  How on earth do I attach underpinning and stuff to them?

Is it ok to use a combination of the two?  The block for the short ones and the pipe for the taller ones?

In general will I run into any issues with piers that tall?  

Thanks guys!

Redoverfarm

Quote from: Dallas2build on March 07, 2010, 02:13:49 PM
Red, after checking out the link I think the blocks would be solid and fairly easy to work with so I like that.  My biggest concern is the precise nature necessary when using the blocks.  Unlike wooden post I can't set them and then cut them all off level.  Also, at that height would they still be stable since they aren't a solid object and instead stacked?

Scott, after giving the metal post some thought, which I really like, I have one major question.  How on earth do I attach underpinning and stuff to them?

Is it ok to use a combination of the two?  The block for the short ones and the pipe for the taller ones?

In general will I run into any issues with piers that tall?  

Thanks guys!

Dallas like I stated before that the blocks are 7-5/8" thick.  So determine at what elevation you want to place your beams.  Then measure down (from string line or beam bottom elevation) in increments of that thickness.  So for example you want your front at 16".  Then that would be 15-3/4".  So the top of your footing would need to be 15 & 3/4" down from your string line.  The back or highwall would be 8 courses and the footing heigth would be 59 &5/8" off the string line. 

I may be off a little as I was doing this in my head but I think you understand.  Once you get the footing at the correct heigth the blocks will not vary that much as they are manufactured fairly uniform.  I think that I would just figured out an even # of inches that thet block works out to and set the top of your footings to that number uniformally. Just make sure that it works out the same elevation from front to back.  If not your glass of water on the kitchen table will always lean. ;)

MountainDon

Five foot tall piers/posts make me nervous, especially with a building as large as 32 x 36. I've seen it done here in the Jemez on some fairly steep slopes. Two that I'm familiar with were engineered foundation solutions. They both involved more concrete than you might think or want to hand mix.

The wind pressure on the side walls and roof can be quite high and with stilts on one end I have no way of guessing what would be suitable construction. When you get more than twenty inches off the ground I think one enters a whole new realm.


My wind map indicates SE OK winds up to 70 mph. Moving NW across the state 80 is reached. Using 70 MPH as a possibility, a 36 foot x 10 foot high wall, plus a roof with a 45 degree slope, I come up with a pressure of around 14,000 pounds on the wall. Gusts that high could set up wiggling or shaking if there was any movement at all in the piers/posts.  Maybe Don_P will see this and have some input?

I can't say what would be the best design for an end elevated as much as 5 feet. I'm thinking of things like scraping away some of the high side by a couple of feet to reduce the height above ground on the lower part of the slope.  ???  

A series of concrete piers with proper footing and rebar and concrete filled would be much better than any wood.

Have you thought about cutting into the slope and building partially bermed like bishopknight?



Just because something has been done and has not failed, doesn't mean it is good design.


Don_P

I like the steel idea, we've used steel posts a couple of times to hold up log cabins that we were relevelling and then came back and hid them within stone walls. Steel alone worries me as far as rust is concerned. You could weld brackets to it easily for cross bracing and mounting bolts.

Another thought is if the posts go from footing to top plate continuous. The wall sheathing then braces the posts and eliminates the hinge at the top of the pier. As long as the post is sized large enough to take the bending forces this would effectively brace the posts. A load of special order treated 8x8x16'ers was at the building supply last week they were $135 each.

Another, frame between short posts and sheath the underpenning with treated ply, go around the corners to lock it in both directions. It doesn't have to go to grade but the deeper(taller) you run the ply on the posts the stronger that shear wall becomes. That row could lap over the floor system and break on blocking up on the wall, weaving it all into a unit. I'd still run bracing on the line piers back up to the floor system in the plane 90 degrees to the wall.

Dallas2build

#10
 [cool] Great input guys!  

For clarification I didn't explain my grade very well.  There will only be one corner that is near the 5' mark.  The front and one side will all be at minimum height for pressure treated beams, 12" right?  The grade is gradual and only really slopes off on the one corner.  About 80% of the piers will be less than 24" and just that corner will hit the 5' mark.  Mountain Don does that reduce the concern about the pier heights?  (btw, who just has a wind speed map sitting around? This is why I love this site, the amount of info and expertise you guys bring to the table is unreal.)

I guess right now I would say I'm leaning towards a combination of using Red's blocks for about 3/4 and then the steel pipe where the grade starts to drop off.  Also I would definetly weld some brackets on the pipe for cross bracing and could incorporate my underpinning into a framed wall complete with sheathing as Don P suggested.  Does that sound like a solid foundation choice?    

Don P, if I fill the pipe with concrete as Scott suggested and paint them does that reduce your fears about the rust?

Don_P

QuoteDon P, if I fill the pipe with concrete as Scott suggested and paint them does that reduce your fears about the rust?
That describes a lalley column. I keep a gallon of rustoleum and spray cans of primer around to heavily coat my homebrew hangers and such. I think you see the positives and negatives, I'll let you weigh the balance.

Dallas2build

#12
Ok, I'm still open to suggestions on the piers but think I have a plan.  It seems like the wisest move would be to shave maybe a foot or so off on the uphill side, use the block reinforced with concrete and rebar for 80% of the piers and then use 8" lalley columns for the tallest ones.  What do you think?  Can someone verify for me the minimum clearance for pressure treated lumber to the ground?

Now, my next question would be suggestions for the beams.  They will be 36' long, so how many is necessary for the 32' wide span?  Will three be enough?  I had figured on using 3 - 2x12's staggered to build a 6 x 12 beam.  Is this big enough and will three beams be enough?  I must have one in the middle as I will be using a ridge beam supported by poles from the ground up.

Suggestions?

SouthernTier

Quote from: MountainDon on March 07, 2010, 03:23:47 PM
Five foot tall piers/posts make me nervous, especially with a building as large as 32 x 36. I've seen it done here in the Jemez on some fairly steep slopes. Two that I'm familiar with were engineered foundation solutions. They both involved more concrete than you might think or want to hand mix.

The wind pressure on the side walls and roof can be quite high and with stilts on one end I have no way of guessing what would be suitable construction. When you get more than twenty inches off the ground I think one enters a whole new realm.

My wind map indicates SE OK winds up to 70 mph.
I'm guessing you probably won't be interested in this cabin for sale for $185,000 in Utah:



It looks like it could get quite windy there:



Those unbraced sonotubes seem pretty tall.  Article says it was built in 1979.


MountainDon

Quote from: SouthernTier on March 10, 2010, 12:34:55 PM
I'm guessing you probably won't be interested in this cabin for sale for $185,000 in Utah


No. That's a great looking place. In the Jemez where our cabin is that would be priced even higher.

Perhaps I didn't stress the part where I said the cabins/homes I have seen well done were built with an engineered solution and that I could not recommend any particular method (as I'm not an engineer). My caution about saying go ahead stems from a building failure many of the longer term forum members will recall seeing here.
Just because something has been done and has not failed, doesn't mean it is good design.

Don_P

Look a little closer though.
The rear section has bracing walls between piers. This is a great idea. There is a massive pier at this end of the braced section. Those appear to be I beam girders.

Things we don't know,
I don't know if the I beams are continuous. I can think of 2 common engineered methods to accomplish this for high wind that would be hidden, a continuous grade beam or a waffle grid, both would be below grade reinforced concrete beams with rebar tied up into the sonotubes bracing them with something very rigid, all depending the tubes can continue down through that to pin in deeply. It would be a mistake to see a building without seeing the plans and imitate only what you think you are seeing. It could also have been built by someone who just taped piers to the surface. The house does have some issues.

D2B,
I started last night but got sidetracked. Treated for ground contact can be in ground contact, that's usually stamped .40, foundation grade is usually .60. I've worked on one house with a treated wood walkout basement on gravel footings, no concrete at all. A treated wood floor directly on a gravel base is code approved. Not necessarily my style but there it is. For a crawlspace I like 18" minimum, it gets mighty uncomfortable closer than that.

For joists and girders the best place to start is in the codebook, this is mine online, the span tables are the same in most of them, chapter 5 should have them;
https://www2.iccsafe.org/states/Virginia/Residential/Res-Frameset.html

Don_P

I had a FEMA Gulf Coast construction file. So this is the high end, but good to know the current "state of the art".
This is a deep pile in sand. The cross bracing spec is worth noting.

Below is a heavy grade beam. The grade beam is a continuous grid crossing under each pier.

Below is a waffle grid grade beam, another continuous grade beam under and connected to the piers .

Piers on a grade beam is a pretty common engineered solution in many other areas.
I can tamp a fencepost buried 3' deep tighter than I'll bet most have done their piers and if you give me a few minutes I can wallow that post in the hole. If you are depending on soil embedment alone for your bracing that is something to think about.

Dallas2build

What a beautiful place!  You know, interested and afford are two entirely different things. :)  I will probably have about $110,000 less in mine when I'm done including the land.

Thank you guys for all the responses.  To make these post more productive and make better use of all your time my weekend project is going to be getting my plans and topography scanned and uploaded to the board.  I really appreciate your help and I don't want to waste your time answering questions without providing you with all the information.  Your time is too valuable for that. 

A couple quick notes though, my cabin will be in the opposite orientation to the slope as the cabin pictured.  As matter of fact my tallest pier won't even be near the height of the shortest ones there I don't think.  Also, I will be building the beams up like Mountian Don on page 16 of his build.  I just need to figure out how many I need and how big I need to build them.

I will get all the plans loaded up this weekend and you guys can really start dissecting it.  Planning this is a blast!

Thanks again!

Onkeludo2

Dallas2build:  I envy your building location.  I used to go to an informal BMW motorcycle rally in that area (right off the Talamina Drive) and fell in love with it. 

One warning, when I was still living in Tulsa, the wife and I went to look at property in the area along the Kiamichi River.  The realtor was more than happy to give me directions to just about any property we wanted to look at and occasionally would drive us out to a property but basically would not leave the car.  After a couple rounds of this I asked him what the issue was.  He claimed he had been shot at more than once while showing vacant land because he stumbled into someone's "patch".  Pot growers were common in the area, and I assume still are, as they could grow under the cover if the evergreens...normally, on land they did not own for obvious reasons.  Of course, the whole thing could have been a tall tale but for some reason I believed it.

So make sure to a good look around your entire 20 acres!

Mike
Making order from chaos is my passion.

Dallas2build

#19
Quote from: Onkeludo2 on March 14, 2010, 11:50:12 PM
One warning, when I was still living in Tulsa, the wife and I went to look at property in the area along the Kiamichi River.  The realtor was more than happy to give me directions to just about any property we wanted to look at and occasionally would drive us out to a property but basically would not leave the car.  After a couple rounds of this I asked him what the issue was.  He claimed he had been shot at more than once while showing vacant land because he stumbled into someone's "patch".  Pot growers were common in the area, and I assume still are, as they could grow under the cover if the evergreens...normally, on land they did not own for obvious reasons.  Of course, the whole thing could have been a tall tale but for some reason I believed it.

So make sure to a good look around your entire 20 acres!

Mike

You are correct sir.  I grew up in the area and like I always tell everyone, I'm one of those hillbillies.  If I don't know them I probably know their brother or mama and daddy.  I've personally never grown, smoked or had any use for the stuff, but I also grew up knowing plenty of families who always had money yet none of them had a job.  

Back when my dad was a kid it was stills you had to look out for.  When I was growing up it was the huge pot patches, many of which were boobie trapped.  I remember walking into more than one, but if you just turn around and walked straight back out you were ok.  In the middle of the summer if you see someone hauling large amounts of water, a tiller and irrigation equipment into the mountains you just turned your head and went the opposite direction.    

I don't condone any of it, I don't use any of it and I don't really like any of it, but my grandaddy taught me at a young age if you're out in the woods and see something you shouldn't, look the other direction and get out of the area.  If you do that your cattle doesn't get shot, your barn doesn't get burned and you don't have any accidents.

The specific area I am in is clear for about 30 or 40 miles around me as we know all the land owners well and we don't venture out of that area any.

Dallas


Dallas2build

I have my plans drawn out, but they are in PDF format.  Photobucket only identifies my actual pictures when I try to browse my computer to upload.  Any suggestions?

Redoverfarm

Dallas if you can save the file to jpg and then send to Photobucket then post I think that is what Don told me.


"  They have to be an image file.   So photobucket is the best way to go; either photograph it or scan it and save as a jpg, gif, png....      "

Dallas2build

#22
YES!  I DID IT!  

Ok guys, before you start tearing into me let me make a few notes.  The size of the doorways and hallway area into and through the utility area and into the bathroom isn't exactly to scale.  They will be 32" doors, but the hallways will 40' so it doesn't feel so cramped through there.  Also the stairs will be closer to 30" instead of the 24' shown.  I did these drawings on e-copy desktop which is not a drawing program, so edits were nearly impossible.  

So what do you guys think?    


Dallas2build

Below are a couple of views of the creek that runs through my property.



Fred_47460

Which are the load bearing walls? How will the roof lay? If the roof peak goes vertically from front to back the wood stove will be at the low point of the roof....which means you will need a VERY tall stack to get higher than the roof. If the peak of the roof IS from front to back I would suggest moving the wood stove to next the stairs.