Building my first Pole Barn with Concrete Slab - Help on first steps

[RikiB]

Hi Everyone! I love this community and all of the amazing posts. I ordered a 40x60 Pole Barn kit from hansenpolebuildings.com and I cant wait to get started. I am having a few problems understanding what to do in the first few steps, hopefully someone out there can give me some tips.

My location is Dripping Springs, TX - South/West of Austin, TX. Out here in the hill country we have rock, and a lot of it.

The first thing I have done is removed the top 4-8 inches of top soil to prepare the site. I used my laser transit and it looks like there is a slope of about 8 inches going down across the 60ft expanse. I scraped and scraped with my John Deere 310D, probably 50 passes to get everything as flat and compacted as possible. My goal is to bring in a ton of Gravel for the sub-base of the concrete slab. Since I plan to bring the backhoe in the barn, I was thinking of going with a 5.5" to 6" slab.

These are the next steps in my mind:
1. Rent a compactor and compact the ground as much as possible
2. Use my skid-steer and rent an auger to drill the pole holes
3. Set the posts
4. Bring in the many yards of gravel needed to go on top of the compacted dirt
5. Build forms and put down plastic on top of the gravel
6. Place all the rebar
7. Have the guys come in to pour and finish the concrete

Here are my questions:
1. Shouldnt I dig a 12" footing around the edges of the concrete, and also have some 12" beams going down the length of the building?
2. If I dig the 12" trenches, can I just use the width of the backhoe bucket? I have a standard size bucket with 4 teeth.
3. When I bring the gravel in, how do I keep it all from falling into the trenches? Am I worried about this for nothing?
4. Would it be better to bring the gravel in before drilling the holes for the posts? (probably so now that I think about it, Im just worried about the gravel falling into the holes)
5. The poles will be on the edge of the concrete, where the footings are, so those holes will need to be much deeper due to the 12" dug already.

I am just looking for some insight into the first steps so I dont make any big mistakes. Thanks for the help!

 

[davedj1]

I don't see any need for 12" around the edges or the beams either. You don't get any frost down there. I would drill, set posts then fill in with the gravel, you want to compact around the post and a course gravel will act like barbs and keep the posts from up-lifting. At least that's what we do up here.

 

[Ed of all trades]

You don't need the footer, just put a ground contact 2x12 around the posts and spread the gravel and pour the crete. the 2x12 is your form and your bottom nailer.

 

[MarkV]

Sounds like you plan to pour the slab before you finish the barn, or did I misunderstand? Most often the slab is poured after the barn is complete. If your posts are pressure treated 6x6's you don't want them setting too long before they are tied together by the rest of the structure. They tend to wrap and twist when left standing free. And I agree, there isn't any reason to add the footing or grade beam on a pole barn.

MarkV

 

[bucktaker]

Level your Pad, Add base material (we use crushed limestone here) to level and depth of min 5 inches. plate compact if you wish
Drill and set posts, Frame entire building including roof, Install roof material.
Adding utilities or unground drains? now is the time
IMHO a solid 4" inches of fiber reinforced concrete is sufficent
Pour and finish concrete pad including apron if using. Open walls make it easy to pour, screed, finish
Complete the building sides

 

[mx842]

I would think that you should get some kind of drawing or plans with a store bought pole barn package. In those should be a site plan that gives details on post location and how to prepare the site before you start. If you don't get some kind of building plan with the package I would be a little suspect of just what kind of building you are buying.

Building a pole barn doesn't take a rocket scientist to do but you do need some basic skills in building construction to be successful. not knowing what your skills are it's hard to offer any kind of real help to some of your questions. Knowing a little about TX. you are right about red dirt and rocky soil so compaction should not be too much of a problem just get the site as level as possible and back fill the low areas with crushed stone. If the site is really rocky and you can't cut any deeper then you are probably going to have to raise the whole building pad up at least a foot on the high end to get drainage away from the building.

Rocky dirt also presents a problem when digging your post holes depending on just how large the rocks are. I sat my post on concrete piers and tied the post to the piers with steel angle iron straps I made in my shop. Some times in real rocky soil this is the best way to do it but you will need to see what the plans say and also check with the local building inspector to see what they like to see in your area. If you are going to have to get it inspected you pretty much have to go with what is on the building plans as that is what the inspector will go by to see that he/she and the manufacturer are on the same page.

Although with pole barn construction you can pour the floor at anytime, before during or after it is under roof and otherwise complete. A nice concrete floor is nice to work off of but not doing it until later gives the dirt under the pad time to settle and you can add stone as you go along so it can be settling as you work so when you are ready the finish grading will be minimal just freshen up what base you have already, add or remove material and pour. The main reason I would rather wait to pour the floor until after the roof is on is that although working off concrete is nice you will be tracking red mud driving all sorts of machines over your nice new floor making it old before it's time. Also the TX. sun is not your friend when it come to pouring concrete and having it cure properly. If you have a roof over your floor it will have a better chance of curing slower thus making for an all around better finished product in the end. It will also give you time to change your mind about plumbing options, conduit for electrical runs, even possibly adding tube to the slab for maybe later on adding radiant heat. Just some points to ponder as you are preparing your project. Good luck and have fun while working on your project.:drink:

 

[GPintheMitten]

I would do slightly different. After getting site as level as possible, I would put posts in, frame building and roof as Bucktaker said, leaving siding off. Then I would strike the bottom plate 2x12 off level. Then backfill, compact, then concrete, then siding.

 

[kneedeep]

all good suggestions and ideas :thumbsup:

One more thing to ponder frpm a southern contractor- Slabs on fill will weaken around the edges once the forms are removed. the gravel will slough out and the slab will not contact the ground around the edges making a weak area. A small (8"W x12"D) turned down footing will make the slab stonger and less likely to break off. The areas that you will be driving over to enter and exit need a footing or it will break. Rebar through the footings will help. Saw expansion joints in the slab to control the cracking (ALL concrete cracks!).Compacted base will help prevent slab cracking too much also. If you use footings, place the base first, compact as close to the edge of the footing as possible and clean out the stone that falls in before placing rebar. Makes a great slab!

Just my :2cents:

 

[jkarst]

I've seen the Hansen Pole Building website. How much did that size run you?

 

[jimgerken]

Like Kneedeep said, be sure to thicken the edge where the stress of driving on and off is greatest. And get some rod near the bottom of this section. If the large equipment doors are all on one side, consider going all across that side (at least) with the thickened edge. I'd go all aound if it was me, if you add up what this costs it amounts to large return on investment. Also, I agree with the poster who suggested leaving the wall tin off till you have the floor poured. It really helps with access. Good luck.