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I’m looking to install a fence but a month ago I had some pipe work done in the yard and it left my backyard in shambles. The ground is still unstable and not compacted where the fence line is going to be.

I'm not going to spend a ton of money fixing that, so should I wait until next year when the ground is settled before installing the fence and posts or is it fine now?

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You just need to compact the soil properly around your posts or footings. It's don't on almost any construction site. The nuances of that depend on specific conditions, but here are some tips:

  • Use a pole, such as a piece of lumber, to pound the soil.
  • Rent a compactor. Several types are available. "Jumping Jack" units are far more effective than vibrating plates.
  • Use water. If you have good drainage, water can very quickly settle soil to a nearly undisturbed state. If you don't have good drainage, however, you'll have a mess for days.
  • Work in layers, or "lifts". Soil does a great job of bridging, so attempting to compact too deep a lift results in poor compaction below the surface.
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    You certainly don't want to use water AND a compactor. In my neck of the woods we have a lot of clay soils, terrible drainage. A contractor friend of mine had to remove several dump truck loads of wet soil and replace with crushed rock so the project could proceed. And even if you dig up clay and put it back, it doesn't compress worth a damn.
    – George Anderson
    Oct 11, 2022 at 15:25
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    Yeah, a little spritz can really help settle some soils, but not much at all and not clay.
    – isherwood
    Oct 12, 2022 at 2:11
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Patience will indeed pay off, unless you would rather pay money to be in a hurry.

If you can live without the fence until next year, waiting costs pretty much nothing while expending effort on compacting costs money, time, or both. Freeze/thaw cycles do a fine job without you lifting a finger. You might want to tidy the shambles a bit before the freezing starts, but waiting on the fence will save you money and effort.

It's not uncommon to see things that have supposedly been compacted settle further after a winter. If you do tidy up, leave a bit of a mound over any trenches.

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  • One season would get soil roughly 50% of the way back to where it started. I wouldn't consider it adequate for supporting a fence against the breeze.
    – isherwood
    Oct 12, 2022 at 2:12
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    Freeze/thaw cycles don't work in places where it never gets cold enough. Time will probably still help, but you can't rely on the same processes in Ecuador that you can in Canada. And we don't know where the asker lives.
    – Hearth
    Oct 12, 2022 at 4:34
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We can't really tell you if you should do it now or wait until next year, because we don't know how urgent it is that you get the fence installed.

However, if you want to do it now, where I am, rental of a small plate compactor (first pic) goes for under $100 per day, as does a vibratory rammer or "jumping jack" (second pic).

image of a hand operated plate compactorimage of hand operated vibratory rammer
Images courtesy of UnitedRentals.com. No endorsement intended or implied.

While it won't be perfect, running that back and forth along the area where the fence is to be installed will go a long way toward creating a solid foundation into which you could drill holes & place fence posts.

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    Plate compactors are relatively ineffective on deeper soils because of their large surface area and weak impact force. They'd need to be used in lifts of no more than few inches. They're mostly for flattening soil, not compacting it deeply.
    – isherwood
    Oct 11, 2022 at 14:14
  • Noted. Updated.
    – FreeMan
    Oct 11, 2022 at 14:20
  • Gotta agree with @isherwood . They best way would be to remove some of the soil over the pipes, compress it, add back a few more inches and compress again, do again until you get to grade. But not all soil is compressible, esp if it's wet. You may have to get some crushed rock to replace some of the soil and compact it, then top coat it with soil.
    – George Anderson
    Oct 11, 2022 at 15:14
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The best way would be to remove some of the soil over the pipes, compress it, add back a few more inches and compress again, do again until you get to grade. But not all soil is compressible, esp if it's wet. You may have to get some crushed rock to replace some of the soil and compact it, then top coat it with soil.

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