Phase II began with the process of determining what materials would be best for the restoration. As with all historical restoration projects we attempt to use the same or similar materials used in the original structure. However, we also need to take into consideration environmental/climate conditions, durability and public safety.
We began this process by first looking at the wood that would be used to reconstruct the frame of the greenhouse. Cypress was one consideration as it has been used for many years in the construction of greenhouses and conservatories. Cypress wood is readily available and highly resistant to moist environments due to its natural built in oils that act like preservatives.
However, a new timber product Accoya was favored and ultimately chosen for the project. Accoya has been widely used in Europe for many years, and is now becoming popular with designers, builders and architects in the United States. It is a sustainably-sourced wood that has under gone a non-toxic acetylation process. This process produces a material that is environmentally friendly, extremely strong and durable. Accoya is also the perfect medium for the paint coating, Technos, we planned on using for the surface. Once painted the historically correct color the greenhouse will be restored to its original state and ready to withstand another hundred plus years.
Once the material for the frame was selected the pain-staking process of dismantling the original greenhouse was begun, carefully removing and categorizing each piece. Like an architectural dig, each piece was carefully measured and drawn to scale so the CNC machine could then copy the designs and create exact duplicates.
When it came to the replacement glass for the greenhouse, public safety had to over-ride historical significance. The original roof frames were made to hold 2 layers of 1/8″ annealed laminated glass. Laminated glass works like that of a car windshield – if it breaks it won’t cause extensive harm. We felt very strongly that the glass, especially the roof glass, should all be tempered. Tempering the glass meant that the entire project would have to be modified to accept thicker, more durable glass. In the end, current safety standards won over historical.
As with the frame, all the metal gearing and structural components had to be cataloged, removed and sand blasted before powder coating and re-installation. Many of the components were missing and created quite a hunt for historic greenhouse parts in various ‘boneyards’ around the country. In order for the original metal gearing to work the greenhouse needed to be reconstructed exactly as the original structure was. Site measurements were taken once, twice and then again to make sure every part and partial would be an exact fit to the original.
The work begins. These large piles of rough looking wood are the Accoya. We carefully create the image of the wood items to be made, enter them into the computer and the CNC takes these rough piles of wood and turns them into the finished product.
Three coats of Technos, shop painted and we are ready to install.
Next: Constructing the greenhouses.