Joining two pieces of wood can be quite difficult especially for those who know nothing about carpentry. Let us teach all about the butt joint and how to do it.
Woodworking is a noble profession that has been around for a very long time. To be more precise, Ancient Egyptian woodworkers used mortise and tenon joints around the pre-dynastic period — this is right around the time of the first Pharaoh (hey, even Jesus was a carpenter)! We looked into all the different types of Wood Joinery, but there ended up being so many different methods that have evolved over time, that it was worth taking the time to dive deeper into each one.
The butt joint is one of the most straightforward methods of wood joinery, but turns out there are 6 different ways to reinforce a butt joint! Today we’re going to discover the differences between the nailed butt joint, the dowel reinforced butt joint, the biscuit reinforced butt joint, the screwed butt joint, the butt joint with pocket hole screws, and finally, the knockdown fastener. (Hopefully, you enjoy reading the term butt joint over and over because we’re in it for the long haul.)
Table of Contents
- What is a Butt Joint?
- Reinforcing Butt Joints
What is a Butt Joint?
The butt joint is a wood joinery method where two pieces of wood are brought together end to end without any fancy maneuvering. It is the simplest of wood joints. In woodworking, pieces of wood are referred to as “members”, and cutting processes are referred to as “docking”.
The orientation of the two members are with one being attached along the grain, and the other against the grain at a right angle. Butt joint joinery is usually dedicated for carcase construction, and frame construction.
Carcase Construction: members are joined end to end and assembled using some form of tongue and groove joint.
Frame Construction: members are joined end to end and assembled using some form of mortise and tenon joint.
(Looking to start a woodworking project? If you need advice on which type of wood to use, we’ve got a guide here.)
Butt joining (lol) is also the weakest type of wood joint unless some sort of extra reinforcement is introduced. This can be done with glue in combination with any of the following reinforcement methods:
Reinforcing Butt Joints
The Knock Down Fastener
This is the type of joint you’ll find when you get an Ikea cabinet shipped to you. This kind of joint is designed for when the customer is designated to assemble it themselves, and it’s manufactured to be resilient against constant re-assembly.
This joint itself will consist of cam dowels and cam locks. This is basically one member that has 2 or more cylindrical holes on one end, and the other member has two perpendicularly facing dowels (cam dowels) of the corresponding size on the other members’ end (cam locks).
Usually, these assembly kits will come with specialized tools and an instruction manual for easy assembly, as it requires next to no skill to get the job done. The knockdown fastener joint is used in carcase joinery methods, simple furniture designs, and simple cabinet making.
The Dowel Reinforced Butt Joint
This joint is very similar to the knockdown fastener, but it isn’t designed to withstand constant assembly and re-assembly.
Members have a series of holes drilled into the surface of each joining end. Then on one of the members, each hole will be filled with a dowel that fits snuggly inside. It is crucial that the dowels and holes are perfectly aligned, otherwise, they will not be able to be joined. The hole will be filled with a very strong glue, the member’s end will be brought together so that the dowel is entirely within the hole, and the joint is clamped until the glue has dried entirely.
Even after the glue deteriorates the dowel itself will provide enough reinforcement to hold the joint together. They may become loose, but all it will do is flex the frame a little more. That being said, a dowel reinforced butt joint won’t commonly be used in high-quality furniture manufacturing.
(This type of joint reminds me of when I would be preparing the dinner table for thanksgiving, and we would fetch all of the extra slats to make the table long enough for all of our guests. The slats were inserted into the center of the table using dowel reinforced joints!)
The Biscuit Reinforced Butt Joint
Although very similar to the dowel reinforced butt joint, the biscuit joint is a fairly recent innovation. Instead of a cylindrically shaped dowel, this one is formulated out of dried and compressed beechwood in an oval shape (like a biscuit! So cute!).
The main difference between the two is that with the biscuit butt joint the mortise (biscuit) is designed to be slightly smaller than the hole it will be aligning with. When the member ends are brought together, the corresponding will still be filled with glue, and the joint will be clamped down until the glue is completely dry. The reason why this joint is slightly stronger is due to the fact that the biscuit absorbs moisture from the glue and expands, creating an extremely tight-fitting joint.
This makes for an easier initial alignment as well, since there is slightly more leeway when aligning them, as the measurements don’t have to be laser perfect due to a smaller dowel. This is a very popular joint in frame joinery, cabinet making, and panel assembly.
The Nailed Butt Joint
Another very simple manner of wood joinery, the butt joint is reinforced by hammering nails into the ends. This method is used when aesthetics isn’t a priority, and the joint won’t be visible.
The method of skew nailing is applied to provide extra support. If the nails were all applied parallel, there’s a greater chance of the members pulling apart.
The nailed butt joint is rarely used for furniture making as it is unsustainable and can’t withstand much pressure. This joint will be used for basic box and cabinet making, garden bed boxes, and woodwork toys.
The Screwed Butt Joint
(I’m sorry but that term is just too funny, I have to point it out.)
A step more resilient that the nailed butt joint, the screwed butt joint is technically the same method, but with screws that are more likely to hold in place.
Screws are inserted either parallel or skewed into one side of the member, but the screw must be long enough to reach the grain end of the other. This is where it’s important to measure the required hardware before purchasing.
To make the joint more attractive, a counterbore is incorporated where the screw hole is placed. A counterbore is when an extra little nook is carved into the surface of the member, as a place where the screw head will be just below the surface’s edge. Then a cap of either the same material or plastic can be inserted into the counterbore, disguising the screw placement.
The Butt Joint with Pocket Hole Screws
This is the type of joinery used where structural integrity is the main priority. The most well reinforced of all of the butt joints, the joint with pocket hole screws has a few steps to it. First, a screw hole is made where the member ends meet perpendicularly, and they are aligned at an angle.
Much shorter screws can be used with this type of joinery, as they will plunge deeply into the ends and meet in the middle. Since the screw holes are at an angle, the reinforcement is strong. The remaining room in the screw holes after the screws have been drilled in is then filled with glue and capped with their respective counterbores.
The butt joint with pocket hole screws are one of the most effective methods of wood joinery, allow for a cleaner finished look, and can be used in the manufacturing of higher quality furniture.
What are the types of wood joinery?
There are a great array of types of wood joinery, and even different kinds according to different cultures around the world! We’ve written a great overview of the following types: butt joint, miter joint, tongue and groove joint, mortise and tenon joint, dowel joint, lap joint, full lap joint, notched lap joint, dovetail joint, a dado joint, and rabbet joint.
What is the strongest wood joint?
If we’re looking strictly at types of butt joints, the butt joint with pocket hole screws is the option that will last the longest and withstand the most weight.
Where can I find wood joinery equipment?
Everything you need can be found at most hardware stores. Depending on if you have one in the area, Lowe’s is a great option for finding wood joinery equipment.