Level Site or Poles First

[kmacht]

After getting the runaround from some contractors trying to get quotes for a pole barn I am back to considering doing it myself. I only have two real concerns. The first is setting the poles. I plan on using perma columns (basicly 5 foot pre-cast concrete columns). The area I want to put the barn slopes about 2' over 36' in length so it will need to be leveled. After scraping off all of the top soil am I better off filling and leveling the site first or drilling the holes and setting the perma columns first. Setting the columns first seems easier as it would be less drilling for the holes and I could use them to set the proper height for the finished floor in the barn. On the other hand I am concerned that the columns may move and shift as I backfill and compact the area. Thoughts? What have you done?

Keith

 

[ssdave]

Get all the backfilling done, and then put in the columns. The key in backfill/compaction is consistency. it's a lot easier to get consistent compaction if you don't have to work around something like pillars or posts.

 

[Chris4x4Gill2]

Do your site prep first. Mine started today actually for my pole build.

 

[jimkaniki]

Set the poles, then fill. That way you know that your poles are set in good soil, not fill. If the filling and grading is done with any level of care at all, there will be no danger of the perma columns shifting, so long as they are set in the proper depth of undisturbed soil. I built a 20' by 30' shed this way about 20 years ago. Worked great.

 

[06 DIESEL]

From a construction perspective, backfill then set the posts. As long as the guy doing the backfill is doing it properly odds are it will be better than the soil that is existing.

Not only that, when you have a large area to backfill with nothing in it you can use larger equipment that does a better job faster, when you have to get out a jumping jack to go around columns you do not get as good of a compaction because the guy running the jumping jack is getting beat up and will not spend the time to get the proper compaction unless you have a soils tech there that is taking tests.

If you want to test the backfill for yourself, before they start the next lift take a piece of 1/2" solid stock with a point on it, if you can push it in more than 1-2" you have an issue. Lifts should also be under 12" if using a large roller, 9" or less if using a small roller, 6" or less if using a jumping jack, and 4" or less if using a walk behind plate tamper.

 

[kmacht]

To help clarify, I will be the guy doing the fill and compacting. Plan is to rent a jumping jack or plate compactor and have one person constantly working it while another is dumping and spreading loads of fill with the tractor. Is there an advantage of getting the majority of the fill in first (say within 6" of final grade), setting the posts and then doing a final fill and compaction? Since the drop is only 2' and I have to go down 42" min for the columns due to frost, no matter which way I go the columns will sit on undisturbed soil.

Keith

 

[cj7jeep81]

To help clarify, I will be the guy doing the fill and compacting. Plan is to rent a jumping jack or plate compactor and have one person constantly working it while another is dumping and spreading loads of fill with the tractor. Is there an advantage of getting the majority of the fill in first (say within 6" of final grade), setting the posts and then doing a final fill and compaction? Since the drop is only 2' and I have to go down 42" min for the columns due to frost, no matter which way I go the columns will sit on undisturbed soil.

Keith

That's basically what I did with my site, although I didn't have as much drop. Just make sure you are compacting in lifts like others mentioned. If you put on 18" of fill, then try to compact it it won't get fully compacted. As you said, wont' affect the posts much since they are going down 42", but will cause you problems with your floor down the road (when it settles after you pour and its unsupported).

 

[73RR]

To help clarify, I will be the guy doing the fill and compacting. Plan is to rent a jumping jack or plate compactor and have one person constantly working it while another is dumping and spreading loads of fill with the tractor. Is there an advantage of getting the majority of the fill in first (say within 6" of final grade), setting the posts and then doing a final fill and compaction? Since the drop is only 2' and I have to go down 42" min for the columns due to frost, no matter which way I go the columns will sit on undisturbed soil.

Keith

Do yourself a favor and rent a vibratory double drum compactor.
For fill material, ask your rock pit guys for crusher reject. The stuff I get around here packs in so hard you cannot break it loose without a pick. Hopefully you have something similar since rock is kinda-sorta-similar in most locations. Place it in 6" lifts and keep it moist while rolling it. I had a project where I needed to fill one end over 3' and it worked perfect.

 

[Catadj78]

I built a 40x40 pole barn 2 yrs ago. Had an 18" slope over the 40' at the front and 2' at the rear. Shop was on a hill of somewhat.

Due to the layout of my yard and in relation to the house where the shop was going I chose to dig down to level rather than build up. Much more work this way however the end result was much better imo in my case.

I leveled down to hard clay with a tractor and then set the poles. Finished the building. Had to bring in more clay to get close to level and then sand to get the final couple of inches while the building was up. I rented a bobcat and a tamp to compact every couple of inches before bringing more in. End result was great. I could spin the bobcat around without digging into the clay it was so hard but. If I had it to do over I would get the entire site to within a couple of inches prior to putting the poles up. Concrete has been poured for about a year and not one crack (knock on wood).

 

[LXCam]

Fill and compaction first but if it were me I'd do exactly what cat did. I'd much rather deal with some small retaining walls or a little extra grading for water shed and build on top of natural then **** around with fill and compaction.

Good luck.

 

[06 DIESEL]

To help clarify, I will be the guy doing the fill and compacting. Plan is to rent a jumping jack or plate compactor and have one person constantly working it while another is dumping and spreading loads of fill with the tractor. Is there an advantage of getting the majority of the fill in first (say within 6" of final grade), setting the posts and then doing a final fill and compaction? Since the drop is only 2' and I have to go down 42" min for the columns due to frost, no matter which way I go the columns will sit on undisturbed soil.

Keith

You will be able to put the fill in faster that a plate compactor or jumping jack can properly compact it.

If you are doing the fill yourself ask for a walk behind smooth drum roller, you will be glad you did. Keep in mind once it is "smooth" it isn't compacted, you will need to run over it quite a few times in order to get compaction. The lighter the item compacting the more you will need to roll over the area with it.