Introduction

Butt joint is one of the weakest joint used in wood work construction unless reinforcement is used. It is the process of joining two pieces of materials. The joining occurs at the end of the work piece by placing them together without any shaping.
Butt joint is said to be the simplest joint to produce since it process involve cutting of wood to the appropriate length and butting them together. This joint relies on glue to hold them together.

Reinforced butt joint add to the durability of the joint to overcome their inherent weakness. Adding reinforcement in butt joints required additional steps which is mentioned below.

Reinforced butt joints

Biscuit reinforced butt joint

Biscuit reinforced butt joint is recently introduced in butt joint construction. It has an oval shaped piece which are specially dried and compressed wood it is installed in matching mortises in both pieces of the joint in a similar fashion to a floating tenon. They are particularly convenient for panel glue ups as they facilitate alignment of panel members. Biscuit joint are common in frame and carcase construction.

Fig 1: Biscuit reinforced butt joint

Knock-down fasteners

Knock-down fasteners are a hardware device made for the purpose of constructing butt joints that can be assembled and re-assembled repeatedly (hence knock-down ). This type of fastener is very popular in flat-pack furniture, which is typified by items such as book cases and wall units that come in a package of pre-cut and pre-drilled components ready to assemble by a novice. They are also very common in modern modular kitchens.

Fig 2: Knock down fasteners

Screwed butt joint

The screwed butt joint uses one or more screws inserted after the joint has been brought together. The screws are usually inserted into an edge on the long grain side of one member and extend through the joint into the end grain of the adjacent member. For this reason, long screws are required (usually 3 times the thickness of the member) to ensure good traction. These joints may also be glued although it is not necessary.
In solid timber work it is common to counterbore a hole in the frame or carcase member to conceal the head of the screw.

Fig 3: Screw butt joint

Dowel reinforced butt joint

This type of joint is common in carcase and frame construction. It is also called simply dowel joint which has been a very common method of reinforcing butt joints in furniture. it is mostly used in chairs, cabinets, tabletops and panels. Furthermore, dowel joint are used to assist with alignment during glue up. It technique consists of cutting of wood piece to size and series of holes are drill on it surface of each wood. The purpose of the holes is to aid the accuracy in each wood piece whereby short dowel are inserted with some glue. Dowel reinforced joint produces a joint which is much stronger than a butt joint without reinforcement.

Fig 4: Dowel reinforced butt joint

Nailed butt joint

This type of butt joint is commonly used in building construction. It is the process where by wood pieces are brought together and nails are driven in to hold them in one place. The nails are applied in such a way that they are not perpendicular nor parallel to each other so as to resist pulling apart of the joint. Nailed butt joint is uncommon in furniture making. It is use for framing in building construction, such as temporary box and cabinet.

Fig 5: Nailed butt joint