Wood joinery is an integral part of woodworking or carpentry that has been practiced for thousands of years. From the construction of furniture to building doors and windows to decorations, everything involves wood joinery. In some types of wood joinery, modern tools can potentially make life easier, but most require great precision demanding expert artistic skills.
Like other professions, woodworking has evolved with the introduction of different wood joinery types that have greatly empowered the profession. Wood joinery is basically about connecting two wooden pieces together to create a new, resultant structure. The wooden pieces may include different types of wood such as lumber and timber.
Two significant woodworking tools are important when we talk about wood joinery. These include a jig, that ensures precision in cuts made by cutting tools, and a fence, which is an edge that helps in bracing the sliced material.
Different types of wood joinery have varying degrees of strength. They also differ in the way they hold different wooden pieces together. Before you attempt to primary woodworking skills, make sure you have a sound understanding of all the different types of joints. After all, the quality and durability of the end products are highly dependent on how firmly the pieces are joined together. Let’s have a look at these types:
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Butt Joint is the most common type of joint and probably the first one that you come across while studying woodwork. They are often used to install trims and baseboards, or wall framing at construction sites. They are commonly seen on window and door trim where vertical pieces of trim are butted into the horizontal ones at the top of the window or door or into a horizontal window sill.
In a typical butt joint, two pieces of wood are cut at opposite ends and the square end of one piece is butted into the end or side of the other piece. But they aren’t fastened not at the point of abut, but using nails, metal clips or screws. If wish to ensure firm butt joints, don’t use a hand saw or a circular saw as they don’t help achieve accuracy of angles. Ideally, a chop saw should rather be used.
Miter joints are frequently used in picture frames and some styles of doorway casing. In the case of picture frames, they are used at all the corners, while for some doorway casing styles, they appear in the upper corners.
A miter joint is quite similar to a butt joint as it attaches two boards at their end or joins the end of one board to the side of another. However, the distinction lies in how those ends fit each other. As opposed to meeting at a 90-degree angle as in the case of a butt joint, the ends or end in a mitered joint meet at a 45-degree angle. This helps turn the corner accurately and molds an angled board into a straight board.
Moreover, in contrast to the butt joint, the miter joint helps connect the boards much easily as the nails or screws can be inserted straight into angled boards. Once the boards are joined, no end grains are visible on the mitered joint, making it appear artistic. The joint appears to be neater this way and allows for more possible ways in which the boards can be positioned or angled. Using a miter joint, for instance, a board angled for a roof pitch can be transformed into a vertical board at a side of the house.
However, as compared to butt joints, mitered joints are not that strong. Using a miter saw, that cuts precise angles, helps ensure tighter miter joints, leaving no gaps in between the boards. Also, the piece you’re cutting must be held firmly against the saw to avoid any movements during the cut.
Tongue and groove joints are generally used to position objects that are laid flat such as floor hardwoods or luxurious ceilings. Those who are aware of a laminate or a floating wood floor would probably have some idea about how the tongue and groove joint works. Typically, the tongue and groove joint is much stronger than mitered and butt joints.
This type of wood joint is different in that it attaches two boards together along their edges, not in their center or the ends. Each board has a groove cut along one edge and a deep, thin ridge on the edge at the opposite side. The edge of one board is then notched into a groove, whereas the edge of the attaching board is extended in the form of a thin tongue to that fixes the groove.
To ensure that the tongue is inserted into the groove at an angle, both the tongue and the groove are slightly twisted into a curve-like shape. Finally, once the boards are joined and laid down, they get locked and cannot be detached unless any one of them is held up at a specific angle.
You may opt to craft tongues and grooves along the edges of the board by yourself using a shaper and a saw in DIY hardwood flooring and beadboard. However, most of them already have tongues and grooves cut and all you need to do is fix them together at the time of installation.
Make sure to fit the tongue and groove boards tightly against each other. You can take the help of a rubber mallet as you attach them. In case of hardwood flooring, a hardwood flooring nailer is a perfect tool that joins the boards precisely together, while accurately inserting the nails.
Source: The RTA Store
Mortise and tenon joints are the earliest forms of joints found in ancient structures that date back to thousands of years. They have been in use since the early times of woodworking and are most widely used today. These joints are commonly used in furniture making such as in fixing chair and table legs and other furniture parts.
In a mortise and tenon joint, one end of a wooden piece is tapered and inserted into the carved space of another wooden piece. The carved space is called mortise and the piece that fits into space is called tenon.
Although modern tools have made the practice easier, the quality of the mortise and tenon joint still depends on the skill of the craftsman. For instance, excess wood can be cut away using a router, leaving a square or rectangular shaped space, and a drill press or a plunge router can be used to cut out the mortise. Yet, a skilled craftsman would make sure that the mortise socket is precisely cut into slightly a deeper space than the tenon length. This helps disperse the glue that’s used to attach the wooden pieces to each other.
Dowel joint is quite similar to a mortise and tenon joint in that it too creates joint by filling a socket. What’s distinguishes it from mortise and tenon joint though, is the addition of a dowel which is a totally distinct object that’s cylindrical in shape. Another differentiating aspect is the fact that sockets are drilled out at the opposite ends of both the wooden pieces. The dowel then hammers the tow pieces together. Additionally, a dowel can be used to strengthen all other types of joints.
Dowel joints are most commonly used in wood-crafted projects in which other joint types wouldn’t effectively work. They’re mostly preferred for items on which visible screws and nails don’t look pleasing, such as bookshelves, luxurious cabinets, custom stairways. When the dowels contrast with wood, they often present a rusty appearance, for instance, the use of walnut dowels in oak construction.
Traditionally, dowels were crafted by hand, but contemporary dowels are already molded into cylindrical shape, and sockets are carved using power drills. To achieve the perfect joint, apply glue and fasten the two pieces together let them dry overnight before drilling the socket. In this way, when you hammer the dowel, the wooden pieces won’t move, resulting in a compact joint in the end.
As the name suggests, lap joints are characterized by an overlap of two pieces of wooden. They’re considered ideal for structural framing of houses or to establish support to weaker wooden joints that may otherwise split apart. Lap joints are further categorized into two types, namely the full lap joint and the notched lap joint:
Full Lap Joint
Full lap joints are those in which a wooden piece overlaps another and attached together using a nail or a screw. They are most commonly used to support the structure of a house, but they are also used to strengthen other wooden pieces. For instance, vertical pickets in a gate can be joined together by lapping a diagonal piece of wood horizontally on top of them.
Notched Lap Joint
A notched lap joint is also involves overlapping of two wooden pieces but the pieces are notched before being attached together at the notched segments. The notched lap joint adds additional strength to the frame as they are double reinforced. However, to prevent any confusion about which side to cut (top or bottom) lay out the pieces and mark both surfaces that are to be cut at the same time.
Source: Bob Vila
The dovetail joint is the most ideal and demanded joint in the cabinet and furniture making. The joint is pretty strong and is highly dependent on the craftsmanship and some glue for a little more firmness. Metal clips, nails or screws are required for this joint.
To attach separate boards to each other, precisely deepened, right-angled notches are cut in the ends of both the boards such that they are tightly placed into each other like puzzle pieces. One or more notches are cut in one wooden piece and the corresponding ‘tails’ are cut in the other piece and both are joined together using glue.
Since the notches are firmly positioned, the chances of loosening are very low. Therefore, the finished product has the potential to carry heavy items. It is commonly used in creating the sides of drawers and wooden lids or boxes.
Dovetails today are usually cut using a router. So, make sure you have one, and if you wish to make a lot of dovetail joints, you better buy a dovetail jig for the router. Dovetail jigs give the flexibility your router needs to cut notches and tails that can precisely fix together.
Dado joint is one of the simplest forms of joints you’ll get to see in woodwork. It’s quite similar to the tongue and groove joint since it involves cutting of notch in a wooden piece where another piece can fit. However, the end of one piece slides into the center of another piece.
Helping to fix two pieces of plywood together, dado joint is often used to locate partitions inside cabinets and to put together the backs and sides of dressers and cabinets with the top. It is also used in bookcase units to support the shelves.
As opposed to dado joint, rabbet joint involves cutting a notch at the edge of the boards, rather than at the center. The boards are joined by cutting the thickness of one board to position another board.
Rabbet joint is used to fix backboards onto the backside of pieces. It is also commonly used to connect cabinets or creating boxes in which edges need to fit firmly.