Carpenters and joiners who do woodworking on a daily basis will certainly know when to use a butt joint, and when to use a mitre joint. Someone who likes to indulge in a bit of DIY may not necessarily know that. I decided to write this article to see if I can help explain which each is, and more importantly when to use them.
Making a Mitre Joint
Below you will find a short 4 minute video that shows you what a mitre joint is, how to make it and when to use it. I will show another video below that which does exactly the same for a butt joint.
The mitre is typically cut at a 45 degree angle and then you use two halves to make a 90 degree angle. You can see that a mitre saw is the easiest way of doing that. This is used for framing mainly and also for doing skirting boards and coving or moulding. It just makes a very nice tidy looking wood joint.
It does depend on the type of work that you are doing. The angles of the mitre may change. However the principle is still the same. If for example you were making an hexagonal frame, then you would need to use a different angle to form the perfect shape.
The mitre joint is not that strong, but for items like picture frames that is not that important.
The Butt Joint
This one is the easiest wood joint to make. You are simply making a joint between two flat surfaces. This is used a lot when building framework or stud walls. It is mainly used for rough work or rustic work where to be honest getting the job done is more important than how it looks.
It is a pretty weak joint but it is often useful for doing those basic jobs.
As you can see these joints are typically glued together and then screwed together to make them stronger. You can also use nails and dowels if you prefer. That choice comes down to deciding if it will look alright when the job is finished.
Using Wood Glues to Strengthen Joints
Again you can see from the videos that professionals use strong and quick setting glues to help strengthen the joints. That is always a good thing to so. It also helps hold the joint in place until you can add another form of strength such as nails, screws, dowels or biscuits. In mitre joints splines are also a good method of making a joint stronger.
A simple way of making a strong joint is to use glue and screws that are driven through both pieces of wood. That is usually solid and stable enough for a joint. If you are making a joint that is going to be under a heavy weight or pressure, then neither a mitre or a butt is the ideal solution.
For something like that, a mortise and tenon joint would be a much better option. Also something like a biscuit joint would work better.