Restauration de la toiture de la Chapelle Royale // Restoration of the roof of the Royal Chapel
Roof Restoration Process
Dismantling and Initial Steps
- The original roof was dismantled, including indexing ornaments and angle rafters while removing damaged slate supports. Almost everything is being redone, including slate supports, slates, and 70 tonnes of lead.
New Installation Techniques
- Slates are now attached using small copper hooks instead of the previous method. The new installation involves boarding the roof and nailing slates with two copper screws for durability lasting 80-100 years.
Layout Precision
- The layout process begins by tracing out gauges starting with horizontal sections, followed by verticals and rafters to ensure all slates are level and margins aligned perfectly down the roof.
Structural Support Enhancements
- A new fir support structure has been created using 27mm fir boards. In the vaulted apse, three layers of 9mm poplar are laid diagonally to maintain the vaulted shape.
Material Quality Considerations
- Spanish slate is chosen for its durability; it does not contain pyrite which can cause issues like raised veins in the slate. Box gutters are being remade with 4mm lead while respecting expansion joints for proper functionality.
Lead Handling Techniques
- When working with heavy lead sheets (3m long weighing 120kg), they are heated slightly in cold conditions to aid shaping. Work progresses from bottom to top to ensure waterproofing throughout the roofing system.
Decorative Elements
- An angle rafter ornament made from lead will be part of a total of 200 decorative parts around the building's chapel, all set to be gilded with fine gold. The restoration project began in August 2019.