Under-fence gaps are almost always a symptom of panels being stepped down a gradient rather than the fence being built badly. The fixes range from a cheap board to rebuilding the run properly along the contour.
Diagnostic timeline
Work through these steps in order before booking a repair.
- 1
Measure the largest gap — anything a determined dog can get a head through, it can get through entirely.
- 2
Check whether the ground falls along the boundary or only in one section.
- 3
Look for digging marks along the base, which change the fix from carpentry to groundwork.
Likely causes
Stepped panels on sloping ground
Rigid rectangular panels can only step, leaving a triangular gap under each one.
Ground eroded or dug out
Rain run-off and dogs digging both open a channel along the base over time.
Missing or rotted gravel boards
The board that closed the gap has gone and never been replaced.
Fix options, full-width
Concrete gravel boards, stepped
Panels are otherwise soundCloses the gap permanently and lifts panel timber clear of the soil at the same time.
Raked closeboard
The gradient is continuousBuilt board-by-board to follow the contour, so there is no step and no gap — the proper answer on a slope.
Buried mesh return (L-footer)
Dogs or foxes are diggingGalvanised mesh fixed at the base and turned inward under the soil defeats digging without an ugly visible barrier.
Timber kickboard
Budget fix on a level runA treated board pinned along the base; simple, cheap, will need replacing in time.
Get this fixed properly
Free site visit across London and Hertfordshire, a written specification and a fixed price before anything starts.
Prevention
- Specify raked construction, not stepped panels, on gradients
- Keep a gravel board along the whole run, not just the visible sections
- Address digging behaviour at the same time as the fence, or it recurs
Frequently asked
What size gap is safe for a dog?
Depends entirely on the dog. For small breeds and puppies we close everything to ground level with mesh returns.
Will mesh be visible?
Barely — it sits at the base and disappears under grass within a few weeks.
Can you fix just the worst section?
Yes, and often that is all that's needed on a partially sloping garden.
Does raking cost more than stepping?
Modestly, because it's built on site rather than dropped in. It looks far better on a slope.