Bespoke Joinery for Gilfach Ddu, Llanberis

Derwen Joinery was appointed by T.G. Williams Builders Ltd to deliver a specialist joinery package at the historic Gilfach Ddu site in Llanberis, situated close to the iconic Llanberis Slate Museum. The scheme called for robust external door sets, carefully engineered louvred screens, and fire‑rated internal doors – each manufactured to respect the industrial heritage of the site while meeting modern performance standards.

Our team produced three bespoke external door sets crafted from high‑quality Douglas Fir, chosen for its strength, stability and suitability for the exposed weather conditions typical of Snowdonia. Each door was traditionally manufactured using mortice and tenon joinery, providing long‑term structural integrity and an appearance consistent with the building’s original character. The frames were finished with clean, square‑edged mouldings, while the door leaves were built as framed ledge and brace units with 20mm tongue‑and‑groove double boarding. Insulated panels were incorporated to enhance thermal performance without compromising the traditional aesthetic.