Article summary
Weighing up DIY fencing against hiring a professional, with the costs and risks of each approach.
- Category:
- local
- Read time:
- 9 min
- Published:
- 2 June 2025
- Written by:
- My Homes Fencing Expert
Quick answer: DIY can genuinely work for a short, straight fence on easy ground if you're confident setting posts plumb and to the right depth. But Auckland's clay soil, sloping sections, boundary accuracy and the cost of hiring tools mean most homeowners come out ahead hiring a pro for anything longer than a few metres or on a shared boundary. In fencing, the most expensive fence is the one that has to be built twice.
Here's an honest look at what installing a fence actually involves, where DIY jobs tend to go wrong in Auckland, and when paying a professional saves money rather than costing it.
What a Fence Install Actually Involves
A fence is not palings and a hammer. The real sequence is: confirm the boundary, set out the fence line and post positions, dig the holes, set every post plumb and to depth in concrete, let it cure, fix the rails, then clad and hang the gates. The satisfying visible part is the last twenty percent of the work.
Almost everything that determines whether the fence lasts happens before a single paling goes up. Post depth, post spacing, timber grade and plumb are decided in the first two days and are effectively permanent once the concrete goes off.
That's the honest frame for the DIY question. You are not deciding whether you can nail boards to a rail — almost anyone can. You are deciding whether you can get thirty post holes right, in clay, on a line you have correctly established.
The Boundary: Get This Wrong and Nothing Else Matters
The single most expensive fencing mistake in Auckland is building on the wrong line. It is also the easiest one to make, because the things people use as boundaries — the old fence, a hedge, a driveway edge, a retaining wall — are all things that were themselves placed by someone making an assumption.
An old fence is evidence of where someone once thought the boundary was, and nothing more. Fences get rebuilt slightly off, hedges creep, and small errors compound over decades. Assuming the existing line is correct is the most common way a new fence ends up encroaching.
If there is any doubt, or any tension with a neighbour, the answer is a licensed cadastral surveyor. It costs money and it is trivially cheap compared with removing and rebuilding a fence, or the legal position you end up in if a neighbour discovers your new fence sits on their land. Where survey pegs still exist, find them before you dig.
Post Holes: Depth, Diameter and Auckland Clay
Depth is driven by the fence height and how solid it is. A common rule of thumb is roughly a third of the post's above-ground height in the ground, and a solid close-boarded fence — which acts as a sail — wants more rather than less. Gate posts want more again, because they carry a permanently offset load.
Diameter matters more than people expect. A hole barely wider than the post gives the concrete almost no bearing area against the surrounding soil, and a fence with adequate depth but skinny footings will still work loose. You want a genuine collar of concrete around the post, not a skin.
Auckland's clay is the local complication. It is hard, slow going when dry and greasy when wet, it drains poorly, and it moves with moisture. Hand-digging thirty holes in it is a genuinely brutal weekend, and a hired two-man auger will fight you the moment it finds buried rock, old concrete or a root. This is the specific point at which most DIY fence projects stop being fun.
Setting Posts: Plumb, Line and Concrete
Posts get set to two references at once — a string line for the face, so the fence runs true, and a level for plumb in both directions. Getting one right while losing the other is the classic amateur outcome, and it shows: a fence that is dead straight along the top but has posts leaning at slightly different angles reads as wrong even to people who cannot say why.
Concrete needs to be finished so it sheds water away from the post, crowned rather than dished, and it needs drainage metal under the post base so water is not held against the timber. Both take seconds and both are routinely skipped.
Then you wait. Concrete needs to cure before the posts take load, and rushing to hang rails and a heavy gate the same day is how a set of otherwise good posts end up out of position. Professional crews work around this by sequencing across the job; a homeowner with one free weekend usually cannot.
Where DIY Fences Actually Go Wrong
The rebuilds we get called to share a short list of causes. Posts set too shallow, so they heave and lean after the first wet winter. H3.2 timber used in the ground where H4 was needed, which rots at the soil line within a few years. Post spacing stretched to save a hole, leaving the rails to sag and the fence to flex in wind.
Then the ones that are not about strength at all: site-cut post ends buried without sealing, concrete dished so it holds water against the timber, and a fence built hard against a bank so the palings sit permanently in wet soil.
None of these are visible when the fence is finished. That is what makes them dangerous — a DIY fence almost always looks fine on the day it goes up. The problems surface in year three, by which time the fix means digging concrete out.
The Honest Cost Comparison
The materials are the part people price, and materials genuinely are cheaper if you buy them yourself. What gets left out of the comparison is everything else: auger or post-hole borer hire, a compactor if you need one, concrete, fixings, a stringline and levels if you do not own good ones, and the disposal cost of the old fence, which is heavier and more expensive to dump than anyone expects.
Then there is the timeline. A crew that fences for a living will do in two or three days what takes a competent homeowner four or five weekends, spread across whatever the weather allows. That is not a criticism, it is just the difference between doing something daily and doing it once.
The saving is real on a short, straight, flat run with easy access and no old fence to remove. It shrinks fast with length, slope, clay, tight access and demolition — and it goes negative the moment any part has to be redone. In fencing, the most expensive fence is the one built twice.
Shared Boundaries Change the Calculation
On a shared boundary, this stops being purely a construction decision. New Zealand's Fencing Act provides for adjoining owners to share the cost of an adequate boundary fence, with a formal notice process for proposing the work and a window for the neighbour to respond.
That has a practical consequence for DIY. If your neighbour is contributing to the cost, they have a legitimate interest in the standard of the work, and "I'll build it myself over a few weekends" is a harder conversation than a written quote from a contractor with a warranty. Many cost-sharing agreements fall over at exactly this point.
It also means the paperwork matters. Agreeing the line, the style, the height and the split in writing before anything is built prevents the disputes that otherwise end up at the Disputes Tribunal — and a contractor's quote is a natural document to agree around.
When Hiring a Pro Pays for Itself
Go DIY if the run is short and straight, the ground is easy, access is good, there is no old fence to remove, it is not a shared boundary, and you are genuinely comfortable setting posts plumb and to depth. That is a real set of conditions and plenty of jobs meet it.
Hire out anything involving slope, retaining, clay, tight access, driveway gates, pool compliance, or a neighbour contributing to the cost. Those are the jobs where the difference between a good install and an adequate one shows up as years of fence life.
My Homes Fencing Expert confirms boundaries and consent requirements before starting, uses the correct in-ground timber and footings, and removes and disposes of the old fence. Call 022 315 8987 or book a free, no-obligation written quote — even if you end up doing it yourself, it gives you a real number to compare against.
Frequently Asked Questions
On a short straight run with easy ground, good access and no old fence, yes. Once you add auger hire, concrete, fixings and old-fence disposal — which is heavier and dearer to dump than people expect — plus several weekends, the gap narrows fast, and it goes negative if anything needs redoing.
A common rule of thumb is roughly a third of the post's above-ground height, more for a solid close-boarded fence, and more again for gate posts. Hole diameter matters too — a hole barely wider than the post gives the concrete almost no bearing against the soil.
Not from the old fence — that's just evidence of where someone once thought the boundary was. Look for existing survey pegs, and where there's any doubt or any tension with a neighbour, engage a licensed cadastral surveyor. It's trivially cheap next to removing an encroaching fence.
Yes, and put it in writing. The Fencing Act provides for adjoining owners to share the cost of an adequate boundary fence through a formal notice process. Agreeing the line, style, height and cost split before anything is built is what prevents a Disputes Tribunal outcome.
Usually shallow post holes, holes too narrow to give the concrete bearing, or posts spaced too far apart. Auckland's clay compounds all three — it drains poorly and moves with moisture, so a marginal footing that would survive in free-draining soil works loose here.
No. Anything in ground contact needs H4 treatment; rails and palings above ground want H3.2. Using H3.2 in the ground is one of the most common DIY mistakes and it rots at the soil line within a few years — and always seal any post end you cut on site.
A professional crew typically does in two or three days what takes a competent homeowner four or five weekends, spread across whatever weather allows. Concrete also needs to cure before posts take load, which is easy to sequence around on a full-time job and hard on a one-weekend one.
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