Fencing for Boulder County Dogs

Boulder County keeps working dogs. Vizslas on trail runs at Mount Sanitas, Australian shepherds behind houses in Longmont, mountain mutts with a little of everything in Lafayette, and a steady population of Huskies and Malinois that treat a four foot fence as a suggestion. Coyotes are not an abstract rural concern here. They run Boulder open space corridors into residential neighborhoods east of Broadway and south of Baseline, and mountain lions still take small dogs out of yards in Pine Brook Hills and Sugarloaf a few times a year. A fence that contains a dog and discourages what comes looking for a dog is a specification question, not a product question.

Height, by breed and behavior

Manufacturer height charts do not account for an individual dog's athletic profile. What matters is how they use the fence, not what they weigh.

• Small breeds that do not jump (dachshund, bulldog, most terriers under twenty pounds): four feet is sufficient.
• Medium breeds with normal energy (labs, goldens, most retrievers): five feet is adequate if the dog is not actively a jumper.
• Athletic medium and large breeds (vizsla, shepherd, Malinois, boxer, most shepherd mixes): six feet, minimum.
• High drive working dogs and escape artists (husky, Australian cattle dog, border collie when bored, any Malinois): six feet plus a two foot 45 degree inward lean at the top, or a solid face that offers nothing to push off.

One useful rule: whatever height a dog can put two paws on while standing is the height at which that fence will become a problem. Measure the dog standing on its back legs against a wall. The fence top needs to be at least twelve inches above that.

Gap spacing for small dogs and puppies

For any household with a small breed or a puppy, picket gap spacing is a safety item, not just an aesthetic one. The industry standard four inch gap is wrong for anything under twenty five pounds. We spec three inches maximum on dog yards with small breeds, and some breeds require two and a half inches. A puppy that can get its head through a gap can get stuck in it, and head entrapment injuries are common enough that it should be designed out, not managed after.

On horizontal slat fencing, which is popular for modern Boulder houses, the gap becomes even more important because the dog has a continuous vertical opening to work through. For horizontal slats with dogs, we run two and a half inch gaps on the bottom four feet and widen to three and a half inches above.

Dig prevention

Dirt under a fence is an invitation, and some breeds cannot stop themselves. Three solutions, in order of permanence:

1. Extend the fence six inches below grade, with the bottom rail or cedar kickboard buried. Works for most dogs.
2. Pour a concrete grade beam between posts, shallow and continuous, so the bottom of the fence is locked to a hard surface. This is what we do for committed diggers and for coyote resistance at the same time.
3. Install a buried hardware cloth L footer, 18 inches wide, turned outward from the fence. A dog that digs at the fence line hits wire six inches down and learns to stop.

The concrete grade beam has another advantage on Boulder clay soils. It locks the base of the fence against seasonal ground movement, which keeps the bottom line straight across years. That is an aesthetic benefit as much as a functional one.

Climbing and escape

Climbing dogs work a fence from the inside. They find a foothold on a horizontal rail, push off, and hook a paw over the top. The specification answer is to deny footholds. On the dog facing side of the fence we keep the interior face smooth. Horizontal rails, which are standard on most cedar privacy fencing, run on the neighbor side. Pickets are attached from inside. From the dog's perspective, the fence is a vertical wall with nothing to grip.

For serious climbers, a 45 degree inward lean at the top adds a step the dog cannot negotiate. We fabricate these in cedar or in blackened steel depending on the aesthetic of the rest of the run. It reads as an architectural detail from outside and functions as a lid from inside.

Gate hardware, the failure point

Most dog escapes we see happen at gates, not over fence lines. The chain is as strong as the weakest link, and the weakest link on residential gates is usually a spring latch that does not consistently engage when the gate swings closed. We specify, across the board, for any yard with a dog:

• Self closing hinges with gravity assist, not spring loaded.
• A gravity drop latch, mounted high enough that the dog cannot nose it open.
• A secondary slide bolt or carabiner loop for redundancy.
• A latch release mounted on the outside only, or inside a key operated housing, so the dog cannot teach itself to trigger the release.

On double gates, the inactive leaf should drop bolt into a ground cup so the active leaf has a rigid jamb to latch against. Double gates with only a surface mounted bolt pop open under a forty pound dog hitting them at a run.

Coyotes and the foothills question

Coyote pressure varies across the county. It is real in South Boulder, east Boulder along Baseline and Arapahoe, Lafayette on the east side, and anywhere adjacent to an open space corridor or creek. Standard residential fencing under five feet does not stop a determined coyote. Coyotes jump a five foot fence without difficulty from a standing position and can dig under anything not keyed to grade.

For small dogs in coyote territory we build to a different spec: six foot fence, concrete grade beam at the base, coyote rollers along the top rail, and gates rated to the same height and depth. Coyote rollers are free spinning cylinders that defeat the paw hook move that lets a coyote clear the top. They are industrial, not architectural, but in backyards where coyote sightings are weekly, they are the right tool.

The material question for dog yards

Cedar, vinyl, and steel all work for dog containment when specified correctly. Cedar is warm, forgiving of incidental chewing on edges, and easy to repair one board at a time. Vinyl is maintenance free and easier to clean, but splits on impact in cold weather if struck hard. Steel and aluminum are secure and visually transparent, which some dogs find stressful because they can see every delivery driver and squirrel pass by, and some owners prefer because the yard reads as part of the landscape.

For most Boulder County households, the answer is a cedar perimeter at six feet with the interior face smooth, a concrete grade beam, and stainless gate hardware. Adjust from there based on breed, pressure from the outside, and the architecture of the house.

A final note on invisible fences

Electric perimeter systems are not fencing. They do not contain a motivated dog, they do not keep coyotes out, they do not stop a delivery driver from walking into a yard, and the behavioral research on their use is mixed at best. For some situations they are a useful supplement inside a physical fence. As the primary enclosure, we do not recommend them and we do not install them.

To walk a property and specify a fence around the dogs that actually live there, request a consultation. For the materials we work in, see cedar and blackened steel and aluminum.