As craftsmen, we're always thinking about the materials we use and the implications of these choices. Today, we are turning our attention to the foundational element of the Chesterfield sofa: the frame.
When built correctly a Chesterfield frame will far outlast its leather or fabric covering, allowing its owner to reupholster it over the decades.
What materials are used to build a Chesterfield frame?
As artisans, three key considerations guide us when choosing wood for a frame. First and foremost, as we build furniture to last - we need strength and durability. We are also aware of our responsibility to the planet and know that the things we craft can only be as good as the environment they come from. This means we only consider suppliers who take a proactive approach to their environmental responsibilities.
When considering which wood to use for a frame, we have two main options, hardwoods and softwoods.
Softwoods grow quicker than hardwoods which makes them a cheaper option. In most cases, because of how quickly they grow, they lack the strength required to make a high-quality frame. Furthermore, the majority of softwoods are harvested from the Loess Plateau in China, where producers have little incentive to consider their environmental impact. In this region, exploitative harvesting practices have shrunk forest coverage from 53% to 8% - making them an irresponsible choice.
Hardwoods, on the other hand, take decades longer to grow. With tight growth rings, they are strong, dense and hardwearing. As hardwood buyers, we have the luxury of choosing from a variety of suppliers that are doing the work to minimise their environmental impact. Hardwoods are more expensive than softwoods, but their durability and strength make them the only choice for a Chesterfield frame.
What species of hardwood are best for a Chesterfield sofa frame?
Hardwoods such as mahogany, oak, beech and walnut are excellent choices. Whilst each type of wood has its unique characteristics - when made correctly a Chesterfield frame from any of these woods will last well over a century.
It's very rare as artisans to avoid something that looks beautiful, but as a Chesterfield's frame is completely hidden - investing in a walnut of mahogany frames makes little sense, as the true value of these woods is in their beauty.
At Portabello we use Norwegian birch to make our frames. This Scandinavian hardwood is strong, durable and sustainably sourced. Norway is NEPCon certified as low risk and is gaining more forest than it's losing. Although not as beautiful as mahogany or walnut, it's just as strong.
How is a Chesterfield sofa frame joined together?
Whilst material choices are an important consideration for durability, a sofa frame is only as strong as the techniques used to join it together.
We create stable joints by combining corner blocks and dowel joints. Dowel joints are created by drilling holes into the wood and connecting them with glue and a dowel pin. For further reinforcement, we use corner blocks. These are small blocks of wood which are attached to the inside of the frame at each corner, providing additional support and stability.
What is the process of building a frame?
Because all of our sofas are made to order, our joinery department cuts each frame by hand specifically for your order. On our 1694 Chesterfield, 104 pieces are sewn to size from solid birch beams.
After carefully sawing the wood, a joiner will begin the assembly process by drilling 320 holes to accommodate the dowel joints. We then use glue to fix the dowels in place and join the sofa frame together. After 24 hours when the glue has dried and cured, we reinforce the joints with screws. Coupled with Norwegian birch, this dowelled, glued and screwed construction creates a Chesterfield that can withstand up to 600kg.
How do we ensure the high-quality of our frames?
Using robust materials, and traditional construction techniques that have been tried and tested over generations delivers a quality frame that we have confidence in.
Every time we are lucky enough to reupholster a decades-old Chesterfield sofa, we reaffirm our confidence in our design choices. Peeling back leather to reveal a strong and durable frame that has endured for so many years demonstrates the value of our design choices.
Need more information?
If you have any questions about the materials we use or the techniques that bring them together, please get in touch. We're passionate about everything Chesterfield and would love to answer your questions.