Wood Framed Sofa Types and Joints

Buying a new sofa can be difficult at times as it has so many varieties in it. Different materials are being used for upholstery, frame, and cushions, etc. However, the main things which are going to decide whether your sofa will last longer or not and how much weight it can take depend upon the type of wood-framed sofa, the material of the frame and what are the types of joints that are being used, the answer of these questions can easily tell you the life span of the frame.

There are two types of frames that are being used one is Kiln-dried hardwood and the second is engineered wood frame? So, with which one you should go kiln-dried hardwood or engineered wood frame?

Kiln-dried Hardwood

Kiln-dried hardwood is being used in top-quality sofas because of its higher quality, durability, and long-lasting life. The wood is dried in a kiln (oven), to remove moisture in it, usually, 90-95% moisture is removed. By using this method wood can be dried faster than using the air-drying technique. By removing moisture wood is prevented from warping, and bowing that’s why it durable and long-lasting. 2” thick pieces of hardwood are used to make frames, and usually, dowels and glue are used as a joint.

Kiln-dried hardwood frame is considered the best type of frame because of its durability and higher quality.

Engineered Wood Frame

Engineered wood is man-made wood and manufactured by binding or fixing the strands, particles, fibers, and composite boards together with adhesives. There are two types of engineered wood:

• Plywood
• Particleboard (also called fiberboard or composition board.)

Plywood

Plywood is manufactured from multiple thin layers of lumber which are glued together under high pressure. Due to this, plywood becomes strong and stable in the construction of frames. However, plywood has different grades and qualities so make sure to check that your plywood frame is structurally sound, and higher number of layers are glued together and good connection joints are used.

Particleboard

Particleboard is less-stronger than plywood and hardwood. It is made by gluing wood chips and fibers together. These are the cheapest frames that’s why have lower quality. If you are looking for a durable and long-lasting sofa never buy it if it has a particleboard frame.

While considering the above factors make sure to check the reputation of the manufacturer. Soft kiln-dried wood can be weaker than a high-quality plywood frame so make sure to check these factors also check the type of joint, if the joint is weaker there is no benefit of having a stronger frame material because ultimately it will get cracks.

Type of joints – Furniture Construction

Frames of furniture are joined together by different techniques so that it becomes durable, long-lasting, and can take a higher load without wobbling. Some solid types of joints are given over here:

Mortise & Tenon: 

Mortise and Tenon method is the strongest method to join the wood pieces by tenon, glue, and pins. This method is usually applied, when two pieces of wood are at a right angle (90 degrees) to each other. A hole is made in one piece of wood and the other is cut in such a way that it fits into that hole which is made earlier. Then pins are applied to lock the joint, this gives additional strength to the frame.

Double Dowel:

The double dowel is not as strong as mortise & tenon but still is a great choice and is commonly being used in sofa frames. In this technique, two dowels are used at each joint as the name suggests. Two holes are made in two pieces of wood and these dowels which are small, wooden cylinders are inserted into them to hold them together.

Dovetailed Cross Rails:

Cross rails are dovetailed to strengthen the frames from side to side. They are better than double dowel however if they are not properly made, they can lose the advantage over double dowel as they are a little difficult to make.

Half-Lap Joint:

A half-lap joint is made by joining two pieces of wood together, the half-width of these two pieces is removed so that they can overlap each other to make a joint. These can be quickly made and provide reasonable strength.

Spline Joint:

In the spline joint, a strip is inserted into grooves along the edges of two boards. A spline joint is usually used to strengthen a mitre or butt joint.

Butt Joint:

The butt joint is made by butting two pieces and then attaching them by using glue or screws. It is the simplest joint but also the weakest.

Stapled Joint: 

The stapled joint is made by stapling different pieces of the frame together to hold them. It is the cheapest joint type however has lesser durability and strength.

What Is The Best Wood and Joint for a Sofa?

Look for:

• Kiln-dried hardwood or High-quality plywood
• Mortise & Tenon Joint or Double Doweled joints
• Screws and glues can be used to provide additional strength

Avoid:

• Kiln-dried softwood, particleboard, and low-quality plywood
• Stapled, glued joints