Gaithersburg, MD Swimming Pools & Spas: Fencing Requirements (2026)

Montgomery County Code Chapter 51 (Section 51-15) establishes comprehensive mandatory pool barrier requirements that apply to all properties within Gaithersburg. The barrier requirements are modeled on the International Swimming Pool and Spa Code and are designed to prevent unsupervised access by young children, who are the most vulnerable population for drowning incidents. The 60-inch (5-foot) minimum barrier height was established for pools installed after January 1, 1990, and represents one of the taller barrier requirements in the region. The barrier must completely enclose the pool on all sides, with no gaps or openings that would allow a child to bypass the barrier. The fence design must not have features that could serve as hand-holds or footholds for climbing. This means horizontal rails, decorative elements, or chain-link mesh openings that could facilitate climbing are discouraged or prohibited depending on their specific configuration. The maximum opening size in the barrier is 4 inches, measured as the diameter of a sphere that could pass through any gap in the fence, gate, or wall. This standard is based on the physical dimensions of a young child's head and body. Gates are the most critical component of the barrier system because they represent the most common point of failure. All gates must be self-closing (equipped with a spring, pneumatic closer, or gravity hinge that returns the gate to the closed position after being released) and self-latching (equipped with a latch mechanism that engages automatically when the gate closes). The latch must be located on the pool side of the gate at a minimum height of 48 inches above the ground (54 inches is recommended for added security), placing it out of reach of most children under age 5. If the gate has an opening near the latch that could allow a child to reach through from the outside, the opening must not exceed 1/2 inch within 18 inches of the latch release. Pedestrian access gates must swing outward, away from the pool area, so that pushing on the gate from the pool side does not open it. Where the dwelling wall forms one side of the pool barrier, any door that opens directly from the house into the enclosed pool area creates a potential bypass of the barrier system. To address this, the door must be equipped with an audible alarm that activates when the door is opened, alerting occupants that someone may be accessing the pool. The alarm must produce a sound of at least 85 decibels measured at 10 feet. Alternatively, the pool may be equipped with an approved automatic safety cover that meets ASTM F1346 (Standard Performance Specification for Safety Covers and Labeling Requirements for All Covers for Swimming Pools, Spas, and Hot Tubs). An ASTM-compliant cover can support the weight of a small child without collapsing into the water. Above-ground pools present unique barrier considerations. If the pool wall itself is at least 48 inches high and constructed of non-climbable material (smooth-sided steel, resin, or fiberglass), the pool wall may serve as part of the required barrier. However, the access ladder, steps, or deck providing entry to the pool must be secured when the pool is not in use. Removable ladders must be physically removed and stored away from the pool. Permanent steps or decks must have a lockable gate meeting the self-closing, self-latching requirements. A deck surrounding an above-ground pool requires its own barrier along the deck edge. The fence/barrier permit is reviewed and inspected by the Gaithersburg Permitting and Inspections Division as part of the pool permit process. The barrier must be installed and pass inspection before the pool may be filled with water. Barrier modifications after initial approval require a new permit and inspection.