Yes, you can put deterrent spikes on your own garden wall in the UK — it is completely legal, provided the spikes are visible and you display a small warning sign if they face a public pavement or right of way. Spikes that deter rather than harm are widely used on boundary walls, coping stones and gate piers, and there is no law that prevents a homeowner from fitting them.
What does UK law actually say about wall spikes?
There is no legislation that bans deterrent spikes on private property in England, Wales or Scotland. The relevant guidance comes from the Occupiers' Liability Acts (1957 and 1984), which require you to take reasonable steps to warn people — including trespassers — of hazards on or adjacent to your property.
In practice this means two things:
- Fit a warning sign if the spiked surface is reachable from a public pavement, alley or shared path. A small plastic sign reading "Danger — spikes fitted" satisfies the requirement. You can buy these for under £5 from most hardware shops.
- Use deterrent spikes, not injurious ones. Spikes designed to deter (animals step on them and retreat) are treated very differently in law from anti-climb paint or deliberately harmful measures. Broken glass mortared into the top of a wall, for example, carries genuine legal risk. Purpose-made plastic deterrent spikes do not.
If your wall borders only your own garden with no public access, a warning sign is good practice but not a strict requirement.
Does it matter what material the wall is made from?
Yes — the wall surface determines how you fix the spikes, and getting this wrong is the most common reason spikes come loose.
Brick or stone coping stones are the easiest surface. You can screw directly into mortar joints using a masonry bit and rawlplugs, or use heavy-duty outdoor adhesive pads on smooth coping stone faces. Mortar joints are preferable because the drill goes in cleanly and doesn't risk cracking the brick face.
Concrete or reconstituted stone copings are dense but drill well with a hammer drill on a slow speed. Avoid percussion drilling on hollow concrete blocks — use a standard rotary bit at low speed instead.
uPVC or composite coping (common on newer builds) can't usually be drilled without risk of cracking or voiding a warranty. For these surfaces, waterproof adhesive pads are the right fix — press the strip firmly for 30 seconds and leave it undisturbed for 24 hours before it sees rain.
Render or painted brick needs care. Screwing through render risks cracking the surface and letting water in behind. Adhesive pads work here provided the render is sound, clean and dry.
Which animals are wall spikes actually effective against?
This depends heavily on the spike design, and it is worth understanding before you buy.
Standard flat, single-height spikes work reasonably well against birds landing on a flat surface. But cats, squirrels and foxes routinely walk straight across them — the spikes are uniform and low enough that a confident climber simply places its paws between them.
Irregular, multi-height spikes are a different matter. The varying spike heights mean there is no predictable gap to step into, which is genuinely effective at deterring climbing animals as well as landing birds. ThornGuard spikes use three spike heights — 12 mm, 22 mm and 36 mm — specifically because that staggered profile stops climbers, not just perching birds. A cat testing the top of a wall encounters a surface that offers no safe foothold and typically turns back.
For most garden walls the animals causing problems are one or more of:
- Cats using the wall as a highway into the garden to dig up borders or use beds as a toilet
- Squirrels running the wall top on the way to a fence or bird feeder
- Foxes using a lower garden wall (under 1 m) as a step up to the fence
- Pigeons and collared doves perching on coping stones and leaving mess below
If you are dealing with climbers as well as birds, a flat spike strip will disappoint you. Check the spike profile before buying.
How wide does a wall need to be for spikes to fit?
Most deterrent spike strips are designed for surfaces from about 50 mm wide upward. A standard UK brick wall coping is typically 100–150 mm wide, which suits most spike strips well.
If your coping is narrower — a single brick on edge, for instance, at around 65 mm — look for a strip that can be split lengthways. ThornGuard strips can be split along their length to roughly a third of their original width, which makes them practical for narrow copings, gate piers and post caps that a full-width strip would overhang awkwardly.
For very wide copings (200 mm+), you may need two strips side by side, or a strip that bends to cover a three-sided profile. ThornGuard strips fold four ways along their length, so a single strip can wrap the top face and both shoulders of a wide coping stone, closing off the surface completely rather than just protecting the centre.
Step-by-step: fitting spikes to a garden wall
- Measure the run. Note the total length and the width of the coping. Decide whether you need full-width strips, split strips, or a combination.
- Clean the surface. Brush off moss, lichen, dirt and any loose mortar. If you are using adhesive pads, wipe the surface with isopropyl alcohol and allow it to dry completely — adhesion to a dusty or damp surface will fail within weeks.
- Cut strips to length. Use a sharp pair of scissors or snips across the sections. ThornGuard strips have four sections per strip; cut between sections, not through a spike.
- Fix in place. For drilled fixing: mark pilot holes at 300–400 mm centres along the mortar joints, drill with a 5 mm masonry bit, insert rawlplugs and screw down. For adhesive: apply the pads to the underside of the strip, press firmly onto the cleaned surface and hold for 30 seconds per pad.
- Cable-tie to rails or posts where drilling isn't possible. Thread the tie through the preformed holes in the base strip and around the rail, tighten and trim the tail.
- Put up a warning sign if the wall borders a public route.
For a more detailed walkthrough of the fixing options, see our fitting guide.
Will spikes damage or devalue my wall?
Screwed spikes leave small rawlplug holes in mortar joints — nothing a squirt of exterior filler can't reverse if you ever remove them. Adhesive pads may leave a slight residue on very smooth stone, which usually cleans off with a solvent wipe.
Planning permission is not required for fitting deterrent strips to a garden wall. They are not considered a structural alteration. If you live in a listed building or a conservation area, it is worth checking with your local authority before drilling into historic stonework — though adhesive fixing sidesteps that concern entirely.
On appearance: modern plastic spike strips are low-profile and unobtrusive compared with the razor-strip products sometimes used on commercial premises. Most visitors will not notice them unless they are looking.
You can see the full product details, including pack sizes and dimensions, on the ThornGuard animal spikes page.
Common questions
Can I put spikes on a shared boundary wall?
If the wall sits on a boundary you share with a neighbour, you should check your deeds to confirm ownership before drilling. In most cases a boundary wall belongs to one party — the one shown by the 'T' mark on the title plan. If ownership is genuinely shared, fit spikes only on your side, or discuss it with your neighbour first.
Do spikes on a wall hurt cats?
Purpose-made deterrent spikes are designed to be uncomfortable to walk on, not to injure. A cat placing its paw on a spike strip encounters an unstable, prickly surface and steps back — it does not get impaled. The key is using a spike with the right height and profile for the animal: flat low spikes that a cat can walk across are worse than useless, because the cat learns the surface is safe. Multi-height irregular spikes are far more effective at deterring without causing harm.
Do I need planning permission to put spikes on my garden wall?
No. Fitting deterrent spikes to a residential garden wall does not require planning permission in England, Wales or Scotland. The only legal obligation is to display a visible warning sign if the spiked surface is adjacent to a public pavement or right of way, as required under the Occupiers' Liability Acts.
Originally published at ThornGuard
