12 x 12 Micro, then 16 X 24 Macro, Eufaula, Oklahoma- Chris & Julie

[Howie]

Chris,

Currently building in NE OK just up the road from you.  Our initial build is a 14x32 post and pier with a 6/12 roof.

I figured the OK frost line to be approx 18 inches to be safe.  I hand dug 21 holes 24 inches deep and 24 inches round.
Seven holes per beam row with 3 beams planned.

I mixed two 80 bags of Quikrete per hole and added rebar so to tie in with the pier and let cure.
I mixed 1.5 bags of Quikrete per pier and set the appropriate size Simpson post bracket on top.
The pier was formed by cutting the bottom out of a 5 gallon bucket and setting that upside down on the cured footing.
I set the post bracket in the pier cement and used wood blocks across the bucket and thru the bracket so it would not sink.
Let sit for one day and move on to the next pier.   

My plan and timing allowed me to sync my hole digging with the footing and pier pours.  Dig a hole, pour the footing and let cure.  Move onto the next hole dig, pour the footing and pour the first pier on the first footing once cured.  That broke up the process and we saw immediate progress instead of a lot of holes or a lot of pours at once.   

Once the piers were done, I positioned approximate P/T post lengths in each bracket and used the infamous "Water Level" to mark the
final post heights and made the final cuts securing them in place, straight and level.  Amazing accuracy with the water level.

From there, we made 3 beams by combining two 2x8's with 1/2 inch plywood sandwiched in between.
With 2x8 floor joists and 3/4 inch T/G plywood sub-floor added, we went vertical from there.

I did add PT 4x4 angled bracing to each post and 2x6 angled bracing between the beams.
We ended up with a very solid base.

Since we will be slowly adding extensions on each end and side with shed-type roofs, enclosing the crawl space will be accomplished via the extensions.   I avoided any cantilever ideas so I didn't restrict any weight concerns with the additions.

With your 12x12 drawing, add a center beam with post and pier and you will have an easier and cheaper time clearing any span calculations.

Hey, these are my thoughts and they are free.  Good luck in your endeavor.
Howie

[MountainDon]

I understand budgets. My personal experience with many different things is that we sometimes have to scale back what we want because what we want is not possible within the budget limit we have have set. Sometimes it simply means a delay while we save up. Sometimes it means we make a decision to just do without the item altogether. Personal experience has also shown me the follies of taking shortcuts or buying something and stretching its capabilities beyond it design.

Some of my personal worst experiences have involved trying to do too much with too little and in taking on tasks I thought I knew well, but in reality did not.


If the readers here have read my entire cabin topic they will know I have acknowledged that I made an error when designing our cabin. I have taken some remedial actions however they are not providing the same quality end result as I could have had if I had approached things differently. My knowledge has grown along the journey. I try to pass it on. Whether or not anyone listens is not my personal worry I guess.

[archimedes]

I think before you make any final decisions about your foundation you should read through this thread  http://countryplans.com/smf/index.php?topic=4952.0

The whole thread is interesting,  with a very enthusiastic builder,  but it starts to get especially interesting on page 9.

You have tornadoes in OK,  right?

[Don_P]

I'll throw in a gravel trench and treated wood crawlspace foundation. Stronger than piers, there's an approved method described in the codebook, and probably worth pricing out. It sounds like you could get 2 rips out of a sheet. I've dug footing trenches with a garden tiller before.

[DmnYnkee01]

Ok, been playing with sketchup again.  Thoughts on images below?  12" wide x 6" thick perimeter footer (thanks archimedes) , 18-24" deep, with 6x6 posts mounted on top of footer with post base.  8 Posts, approximately 36" tall, half in the ground and half out.  Beams are triple 2x8's all the way around, and 4x4 bracing from posts to beams.  Would price out around $500, also.

[Don_P]

A good start, you have a continuous perimeter footing. Pretty easy to build more strength now.

This would be approaching code and considerably stronger than posts. You could build block corners 4' out of each corner, pour the corner and each end cell embedding an anchor bolt tied to upturned rebar from the footing. The girders would become single rims on sills with a pair of short headers inside the rims over the 4' gaps between the low wide piers.


Building walls of some sort, even low wide wall sections, whether sheathed treated wood frames or masonry is going to be much stronger than a braced post. As an added benefit when the floor joists are on walls as opposed to girders you've eliminated a good deal of bounce in the floor.

[DmnYnkee01]

I did some reading on the treated wood foundation, and thought it was an interesting concept.  As shown in your sketch, it would also price out around $500, but that is not including the gravel that is needed to work as a french drain for that type of foundation.  I would estimate another $100-200 in gravel.

For the block foundation, I would like to stay away from that option.  To me, concrete block and cabin in the woods don't fit together.  I honestly have never liked the look of a block foundation.  I suppose I could put a rock veneer of sorts on it at some point, but would still rather avoid that option.

If I am coming across as hard headed or stubborn, I apologize.  I really tend to over think things, sometimes to a fault. 

[MountainDon]

The PWF is what I think I would have ended up using if at the time I knew what I know now.

[Don_P]

I like rocks 
If you go with the braced posts on a strip footing I'd be tempted to run the braces from the post bottom up to the girder and have a 2x6 skirtboard down there to nail everything to. If it's down on concrete under load it isn't going to slip there. With a skillsaw you could half lap 4x6's and make big X's between posts as well. One thing to think about with posts on a thin strip of concrete, the footing is meant to be uniformly loaded and these will be point loads you don't want to "punch through". Digging a little deeper, smoothly, in the post areas and inserting some rebar in both directions under the post areas wouldn't hurt.

This is a drawing I had, it's another way to brace the posts, run them full height, up to the walltops and let the wall sheathing brace them. This is drawn on spot footings but would certainly be stronger on a continuous one, the shorter the posts below the floor the better, kneebraces certainly wouldn't hurt but notice this just eliminated a weak hinge point where your short post connects to the floor, this has a big lever buried up in the wall. Now rather than worrying about kneebraces slipping and the post to floor connection allowing the post to tip... we check the post for flexure, it's about the strength of materials then, we have a moment resisting connection.

[Squirl]

I know the foundation is an area where you don't want to cut corners, but I am on a shoestring budget. 

By the time you add up the PT posts, brackets, beams large enough to span a distance, there is usually very little to no difference in cost  between most foundation methods including post and pier.

Concrete and mortar are two of the cheapest materials in building.  They stand up great in a moist environment below grade.  In my reading of the PT wood foundation guide, you are in a southern region which is more susceptible to termite and rot damage.

Why not just buy some mortar and build with stone?  Cheap, aesthetically pleasing, stable, heavy.  Very labor intensive though.

I guess I should ask.  I'm from the East.  When I hear the state OK, I think of high wind events.  Is that a possibility in your area?

[DmnYnkee01]

Yes, OK can have some high wind events, mostly from thunderstorms, which can also bring tornados.  I believe the big tree in one of my ealier pictures was altually topped by a tornado in the past as it is not nearly as tall as you would expect with such a large base, 4-5' diameter.

I am actually starting to think the PWF might be the best way to go.  It is a foundation, with the skirting built in, so that would also save some cost.  I also see people giving away gravel on craigslist all the time around here, so I will try to aquire that way if I can.  I will use gravel for the drive as well, so it can always be used.

What I have seen on the PWF, they don't use concrete, but use 2x as a footer.  It said 2x6,8,10,12 should be used, depending on the load.  Are there charts that have load specs for this? Replacing close to a yard of concrete with (4) 2x12x12 would also be a savings, and much easier than concrete with no cure time.  Thoughts?

Another aspect of the PWF that I like, is it will give me the ability to build it in sections at home, and then transport to the site.  I think I could have one 24"spacing on the gable end (lowest load area if I stay away from center) of the foundation where I could create an access door for the crawl space.  I would have never even thought about using PWF if not for this site.  Thank you all!

[MountainDon]

I also see people giving away gravel on craigslist all the time around here

You want rock with broken edges though as in crushed rock, not river gravel with rounded edges. Crushed rock will pack and lock.

[astidham]

if I started my build today, I would use a PWF.

[DmnYnkee01]

Found an excellent resource online for the PWF. http://www.raisedfloorlivingpro.com/pdfs/publications/Permanent-Wood-Foundations-Design-and-Construction-Guide.pdf  In case anyone else reading this thread is interested.

Looking through this, my application would only require a 2x8 for the footer, but I think I will do 2x10 (still cheaper and easier than messing with concrete!).  It calls for gravel of the smaller size.  Too bad, as I found 1"-1 1/2" gravel (crushed rock) here local for $50, per pickup load, that someone was needing to get rid of.

I am already working on getting a quote for rental of  a Terramite 8ft backhoe.  If reasonable, I may go that route instead of trying to dig 44 feet of trench by hand.  We may be able to get back out there on Sunday, as the weather looks like it will be perfect.  I want to get more "thinning" done, and stake out rough locations for the micro and macro and get a better idea on any grade I need to consider.

[MountainDon]

That's the guide I had in mind, but couldn't find. (Didn't take the time to find    )

[markert2523]

I built a 12x16 manshed here in Tulsa a couple of years ago.  I used 8" sonotubes and beams.  I worry about it folding over in a tornado, but seems solid so far.

If I were to do it again, I think I would use a PWF.  The only problem there is finding the correct wood.  The wolmanized finder app seems to say that the closest dealers are in either Tx or MO, so I wonder about the cost.

[MountainDon]

There are other branded names of PT that is foundation rated. You do have to ask for it as not too many places carry it in stock. I found a local dealer who would order it in and the price was quite reasonable.

[new land owner]

When I built mine I just went to the local building supply and they were able to order it for me.

[DmnYnkee01]

I think either Fox or Forrest here in OKC will be able to order for me.

A person should be able to use standard treated lumber for the double top plates, correct?  Zinc coated fasteners would work, but stainless is best, correct?

What would be the best method for treating/sealing any cuts made that will be below grade?

[new land owner]

I used PWF materials for all of the foundation including double top plates.  The cost difference was not that bad.

[DmnYnkee01]

Just when I thought I had a plan, looks like I may be back to the drawing board.  You would have thought I was speaking in Swahili when I asked if they could order in foundation grade PT lumber, I even specified .60 and not the .40 that they carried in stock.  Of the 5 places I called, only 1 seemed to have a clue, but said he would most likely have to order it in full bunks.  That would put my $500 foundation up around $10,000, lol.

I am still waiting for a couple of calls back, but it doesn't look good. 

[new land owner]

I ran into the same issue of bunk quantites when I went to try and order from lowes.  Try the local lumber yards, thats where i was able to buy whatever quantity I wanted.

[Sheldondesigns]

DmnYnkee01...

FIY, in most areas (by code) the live load requirements for living spaces are 40#/sf and for sleeping spaces #30/sf.  Figuring a dead load of 10#, to get 50# total load with SYP#2 you would need to space the 2x8's at 12"oc.

[DmnYnkee01]

I am seeing 12' 10" maximum span for 50#/sf on 2x8#2 SYP at 16" oc using the link provided by Mtn Don, which still surpasses my span by 2'+, however,   I think 40#/sf is more than reasonable for how we are going to use the space, and how often if will be used.  I am comfortable using 2x8's for my floor joists.  I just need to decide on my foundation at this point.  I found a place closer to the site that would be able to do half bunks...still doesn't help me.

I think I am back to the piers, but using 6x6 up to the beams.

[MountainDon]

Hmmm... The IRC Table 502.3.1 indicates the same thing as the AWC.    I know there has been some downgrading on southern pine, perhaps tha has something to do with this?    It is always good to have another person who knows how to look at plans, ideas and proposed designs that come along.