Before we get talking about how a sofa frame is built, let’s talk about the materials being used to build that frame.
A slower growing, denser hardwood such as alder, poplar, maple, teak or walnut are considered more suitable for durable and long lasting furniture.
Softer woods such as pine or douglas fir are still good, but won’t hold up as well as a harder wood species will.
Some manufactures will use fiberboard or particle board in constructing their furniture to keep costs down. The issue with using a material such as this, is that there is basically zero structure or strength meaning it cannot support heavy loads.
The reason why it is so important to get the wood material right is because you want a wood that will hold the staples, nails, glues and joinery in place. The harder the wood, the better it will grab and hold onto whatever item is holding it together. A softer wood is more prone to movement, and overtime will wear down.