Guide · Fencing
Fence replacement or repair
The posts nearly always hold the answer. Here is how to read them, what a complete replacement covers, and what to rethink while the line is open.
A quick diagnosis
Walk the full run and check the following:
- Push each post. Use firm pressure at shoulder height. Movement at the ground means a failed or shallow footing; movement only at the top means loose rails.
- Sight down the line. Stand at one end and look along the top rail. Waves and leans come from footings, while a straight run with weathered boards is a cladding issue.
- Probe the posts at grade. Rot begins where wood meets soil. A screwdriver that slides in easily marks a finished post, however sound it looks above.
- Check the gate. A sagging gate on a sound fence is a repair. A sagging gate beside two leaning posts signals a wider failure.
Repair makes sense when
- Posts stand plumb, are sound at grade, and sit in footings below frost depth.
- Damage is local: a stretch of boards, a single rail, or a gate.
- Height, style and position already suit you.
Replacement makes sense when
- Several posts move in the ground, or the top line has visibly wandered.
- Posts are rotting at grade, which only gets worse.
- Footings are shallow, often visible as seasonal shifting along the run.
- The fence is the wrong height or in the wrong place, so repair preserves a mistake.
- Repair costs are closing in on the cost of doing it right once.
What a full fence replacement includes
A one-word scope can hide a lot of omitted work. Confirm each of these items is covered:
- Removal and disposal of boards, rails and posts, taken off site.
- Old footings excavated, not cut off at grade. Leftover concrete sits where new posts belong and forces irregular bays.
- The line re-established and shown to you before digging. This is when a drifted boundary gets corrected, or the run is matched to a revised landscape plan.
- New footings below frost depth, crowned so rain runs off the concrete.
- Posts plumbed and braced while concrete cures, rather than forced straight later.
- Galvanized or stainless fixings. Electroplated screws corrode in treated lumber and leave streaks down the boards.
- Reinstatement of soil and turf disturbed along the line.
Worth changing while the line is open
With the old fence gone, changes that were costly become simple. Consider these:
Height and the by-law. An older fence may predate current rules and not comply, or you may be allowed more height than you have. Check with the municipality before ordering material.
The gate. Wider, better placed and built for its weight. A gate that admits machinery to the rear yard pays off whenever future ground work comes up, and adding it now costs little.
The line itself. Older fences wander off the boundary. Replacement is the time to correct that, with the neighbour informed.
Board style. Board-on-board or shadowbox looks finished on both faces, which settles the question of who sees the rails. The privacy fence guide compares the options.
Sequencing with ground work. If interlocking, a patio or a wall is planned, install the fence afterwards or leave access. A finished fence blocking the only route means excavating by wheelbarrow.
Specification
What a fence specification has to state
These lines decide whether two scopes describe the same fence.
Footing depth
The biggest factor in both cost and lifespan. Get the depth stated in writing.
Old footings removed
Breaking out old concrete is substantial labour. A scope that omits it describes different work.
Post size and spacing
Larger posts at tighter centres cost more and are what tall or solid runs require.
Lumber species and grade
Cedar versus treated softwood, and the grade within each, shifts the scope considerably.
Fixings
Galvanized or stainless versus electroplated: a minor line with a major effect on appearance over time.
Disposal
Whether old material and spoil leave the site or stay behind for you.
Questions
Replacement questions
Can the existing posts be reused?
Occasionally, after each one is checked. A post that stands plumb, is solid where it meets the soil and sits in an intact footing below frost depth can carry new rails and boards. On a fence old enough to need replacing, though, the posts are usually what failed. Hanging new lumber on them stakes the whole job on the weakest component.
How do I know if it is the posts or the boards?
Push the fence at a post: if the post shifts in the ground, the post is the problem. Then sight along the run from one end, since waves and leans point to footings rather than boards. Finally, probe each post where it enters the soil. If a screwdriver sinks in easily, rot has set in.
Do I have to replace the whole run at once?
No. If one section has failed and the rest is sound, replacing that section is reasonable. Expect a visible mismatch, as fresh lumber beside weathered boards takes years to blend and newer posts age differently. Once setup and access are counted, replacing a full side is often the better value.
What happens to the old fence?
It should be removed from site completely, including the concrete around each post. Old footings occupy exactly where new posts belong. Cutting posts off at grade and leaving the concrete is how a replacement ends up with uneven bays.