Most obstacles can be found before the first hole
Fence and gate jobs rarely go wrong because of the fence itself. They go wrong because something in the ground, on the slope or in the paperwork was not discovered until a crew or homeowner was committed. A walk along the planned line with a probe bar, a shovel and a copy of your plans will reveal most of the surprises. This article covers the common ones and sensible ways to plan for them.
Rock and hard ground
Digging post holes in rocky or compacted soil is slow, and it can damage tools and wear you out. Possibilities include:
- Test holes. Dig or probe a few spots along the line. If you hit stone at a shallow depth, you will know to plan differently.
- Move a post. Shifting a post a short distance sometimes avoids a boulder, as long as spacing and gate openings still work.
- Rent or hire equipment. Heavy augers, rock bits or breakers exist, though they carry their own safety demands. Some contractors have specialized rigs.
- Anchor into rock. In places with solid ledge, posts can sometimes be anchored into drilled holes using methods suited to the rock. This needs a qualified person, since depth and strength matter, and you should not assume it is equal to a normal footing.
- Consider a different design. In very rocky areas, a fence type that requires fewer or shallower posts may be more practical.
For gate posts, which carry the most load, avoid shortcuts. If a post cannot reach the depth needed, ask a qualified installer or your local building office what is acceptable.
Tree roots and trees
Roots make digging hard, and cutting large roots can harm or even kill a tree or make it unstable. Fences can also be pushed over by growing trunks later. Options include:
- hand-digging carefully to find roots before choosing post positions
- shifting a post to avoid a major root
- using a design that bends around the tree, as covered in fencing around trees
- leaving a gap between the tree and the fence line
- talking to an arborist before cutting any root of significant size
Also remember that trees on or near the boundary may be a matter between neighbors. Tree roots are a frequent source of such conflicts.
Slopes and uneven ground
Slopes are among the most frequent complications. A fence can follow the slope smoothly or step down in sections, and each approach affects the look, the gaps at the bottom and the cost. Gates on slopes need extra care: a gate that swings uphill may hit the ground, and a sliding gate needs a level track. Practical solutions include:
- stepping the fence in panels, so each panel is level while posts follow the ground
- racking panels, where the design allows, to follow the slope
- grading the area at the gate opening, or using a gate that swings the other way
- installing a gate with a higher clearance or a hinge system that allows it to rise as it opens
Details for specific situations appear under sloped ground fencing and the coverage of a sloping driveway gate. Whatever you pick, retaining walls or steep banks may add structural and permit requirements.
Buried utilities
This is the obstacle that matters most for safety. Gas, electric, water, sewer and communications lines may run through a yard, often where you least expect. Hitting one can cause injury, outages and large repair bills. Before digging:
- Contact your local utility locating service, where one exists, to have public lines marked. In many places this is free and required by law.
- Know that lines on your own side of the meter, such as irrigation, lighting or private electrical cables, are often not marked by the public service. Find out how to locate them.
- Respect the marks and dig by hand near them, following local guidance.
- Give the service the time it needs to respond; waiting periods vary.
See utility locating for more. Never assume a line is absent because you cannot see one.
Property line doubts
Not knowing exactly where the boundary is can stop a project. Old fences, hedges, driveway edges and neighbors’ recollections are unreliable. Begin with a deed, plat and survey, and consider a new survey if there is doubt. When the neighbor disagrees, early conversation and written agreements are better than building and arguing later. Ideas are discussed in neighbor fence disputes. The measuring side is explained in property line measuring.
Drainage and wet ground
Standing water, springs and low spots shorten the life of posts and bases, and can make footings unstable. Plan so water moves away from posts, avoid blocking natural drainage paths with solid panels, and use materials suited to wet ground. See fence drainage for details.
Easements, setbacks and approvals
Even if the ground is easy, you may not be allowed to build on part of the land. Easements, setbacks and HOA approval requirements can limit position and height. Learn about easements and permitted locations before you stake the line. If the plan has to change, it is far cheaper to change it on paper.
Old fences and debris
Removing an existing fence takes time, and old footings may be buried in concrete. Buried debris or old foundations can also appear. Allow for disposal, and expect the old posts to be harder to pull than they look. If you share the old fence with a neighbor, check who owns it before removing anything.
Build in a margin
Surprises will still happen. Leave room in the schedule and the budget for them, whether you do the job or hire it. Ask installers how they handle unexpected rock, roots or utilities, and whether the quote covers it. A plan that expects obstacles usually finishes sooner than one that does not.