The gymnasium at Auckland Girls' Grammar School in Freemans Bay was refurbished in 2025, with design by DLM Architects and construction by RCC Construction.

The brief was a full refit of the wall and ceiling linings. Because this was a refurbishment, the new linings had to bring an existing space up to current fire compliance, stand up to years of hard court use, and still feel warm and light rather than institutional.

Why birch ply for a school gym?

Plymasters Euro Birch Multiply was specified for the walls and ceiling in 12mm sheets. Its B/BB grade face is near defect-free, which matters on large gym walls where any flaw in the timber would show.

The panel is made from many thin birch veneers glued in alternating directions. This cross-laminated construction gives high impact resistance and strong screw-holding, so the linings can handle stray balls and constant student use.

Meeting Group 1-S with an intumescent coating

Public school buildings carry strict fire safety obligations under the New Zealand Building Code, and the gym linings needed a Group 1-S surface rating.

Euro Birch Multiply is a decorative panel and is not fire-rated in its raw state. To meet the requirement, an intumescent coating was applied to the birch face. When exposed to heat, the coating swells and forms a protective barrier that slows flame spread across the surface. This achieved Group 1-S while keeping the birch on show.

Coating the birch, rather than switching to a separate fire-rated board, meant one panel could run across both the walls and the ceiling. That kept the detailing simple and the finish uniform. The same approach was used on the Francis Douglas Memorial College gym in New Plymouth.

A light, consistent finish

The birch was finished with a clear coat. Its pale face reflects light and lifts the sense of volume in a large hall that is used for everything from PE classes to assemblies.

"Plymasters provided a quality 12mm Birch Plywood product," says Steve Clapham, Director, DLM Architects. "Their premium B/BB grade plywood face is virtually free of face defects. This ensures complete visual consistency across large-scale gymnasium walls, while offering the strong screw-holding power and impact durability required for high-use school environments."