Defining the Mortise and Tenon, Old and New

The mortise and tenon joint is one of the oldest methods of joining two pieces of material together and certainly is still very much a mainstay in fine cabinetry work today. There are many references to mortise and tenon joinery throughout the ages. Historical monuments such as Stonehenge, the hulls of early boat and ship vessels, and even Egyptian sarcophagi were made with this frame construction. Whether stone, metal, or wood, the construction method is still very much the same.

The mortise is essentially a slot or a hole cut into or through one piece of material. The tenon is an extension milled onto another piece of material that will be fitted into the mortise. The outer dimension of the tenon matches in both shape and size to the inside dimension of the mortise. When the tenon is inserted into the mortise, the two pieces of material are joined.

In traditional woodworking, door and shutter frame mortises are milled into the vertical inside of each upright frame member. This upright frame member is called a stile. Mortises are placed where horizontal cross rails intersect. Cross rails, or simply rails, are the horizontal frame members. Rails are made over sized in length allowing for the ends to be milled down creating a tenon.

A well made deep fitted mortise and tenon is very strong since there is quite a bit of surface area contact between both pieces of wood. A snug fitting joint is the best as it will help to prevent the frame from racking. With the use of pegs, wedges or both wedges and pegs, as shown in the pictures of the shutters below, the parts are held tightly together creating a fastened joint.

These aged shutters are well over 100 years old. They are great examples to show mortise and tenon construction with the use of both peg and wedge fastening methods.

The shutter frames are fastened together with both pegs and wedges. The wedge is inserted in the opposite side of where the tenon was inserted. The peg is just below my thumb.

I pulled this wedge out for you to see. It is pretty amazing that someone a long time ago cut this and at least 11 more, all fitted perfectly by hand, for each pair of these exterior window shutters.

The mortise shown on these old shutters is called a through-mortise simply because it is open on both sides, milled all the way through the stile. This mortise and tenon was made to fit a wedge. The wedge pinches the tenon into the mortise slot and holds the joint together much like a wedge shape door stop holds a door open or shut.

Through mortises are seen on objects made in periods in time when milling machinery was not available or advanced enough in order to mill the material quickly and easily.

With the advent of machinery, through mortises for the most part were replaced with "pocket" mortises. Pocket mortises are just how the name sounds. The pocket mortise is open on one face only for the tenon to be received.

We have seen wedges used on many old shutters that we reproduced. However, since we use the pocket mortise and tenon method we only need to use pegs. Pocket mortises are very good for outside applications since end grain is not exposed. The reason that end grain should not be exposed is because just like a drinking straw will suck up water so does end grain. End grain is essentially very much like many tiny straws bundled together that supply the tree and it's canopy with water. When end grain is exposed and proper maintenance is not provided it will eventually lead to deterioration.

More then likely these old shutters would still be hanging if they had had just a little more maintenance with finishing as it appears that this paint is the original finish. For being as old as these shutters are they are still held together rather well because of the well made mortise and tenon construction.

Pegs are inserted into a hole that has been drilled through the face of the shutter through the mortise and tenon joint. The peg acts much like a cotter pin locking the two pieces together.

The mortise and tenon joint is a very old construction method and still one of the best woodworking types of joinery today. Our interior shutters, exterior shutters as well as all of our doors are assembled using this method of joinery.

When we assemble door and shutter frames a light application of glue is applied to the mortise and tenon joint areas. Then the parts of the frame are fitted together along with the components that will be inside of the frame such as operable or fixed louvers or even solid wood panels. The shutter or door is then clamped together to tighten and flush all of the joints. When the joints are flush and tight a hole is drilled through the mortise and tenon for the pegs. After the pegs are inserted the joint is now locked together and the clamps are released. At this point this joint can take extreme force and still not pull apart and it will undoubtedly last as long as the old shutters shown in this post, if not longer.

Did you know? Just because a wood product can mention made with “mortise and tenon construction” does not imply that it is good unless it is properly made. When mortise and tenon joints are too loose, improperly fitted, the joint will fail and the frame will rack.

Post written by Jewel Foulds, April 2008

Spring is no doubt one of my favorite things. Nature is fresh and full of color. I was lucky to capture this picture just recently. This spring time beauty known as 'Bleeding Heart' is an Old Fashioned favorite in many gardens.

Kestrel Shutters & Doors, Inc. www.DIYShutters.com

Celebrating our 19th Year in business on May 4, 2008

The choice between installing bifold doors and sliding closet doors depends on a few different factors. The use of the closet, the space around the closet, and, of course, your personal preference, are all considerations.

What is the difference between bifold doors and sliding closet doors? The first thing to do is to look at how these two types of doors function. Bifold doors, just as the name implies, are a pair doors that are hinged together and fold up together. This means that you can take all of the doors and fold them up to the sides so that they are out of the way and you have almost full access to your closet. With sliding closet doors the doors slide back and forth on multiple tracks and can be stacked up, one in front of the others. Since the doors never fold out of the way, fully exposing the entire area, there will always be some part of the closet blocked.

What is in your closet? Will the closet be for clothes, storage of seasonal items, or used as a pantry? If you will only need to get to one part of the closet at any time then a sliding or a bifold will work well for you. If you need full access to the closet, or you just want to be able to open the doors and see everything at once, then bifold doors are your best choice. Keep in mind that sliding doors can be removed if you should need full access once in a while.

What is around your closet? Is there limited space around your closet? Is there the concern that if you open up the doors they might hit furniture or artwork on your walls? Do you want a streamline fit, rather then doors folding out into the room? If this is the case then sliding closet doors are probably your best option.

Which do you prefer? Another point, just as important as those mentioned above is, simply put, which do you prefer? Even if one of the door installation types is not completely ideal for you, it may still be worth it if you really like the look enough. Regardless of which track hardware you choose, you can still pick whichever style of door you like the most. Every style of door that we offer can be mounted with hardware for either bifold doors or sliding doors .

In my last post, "Finding a Wood Shutter", I included this picture as shown. While it is a beautiful picture of Kestrel European Board and Batten Shutters with a breadboard top, I noted that there is something wrong with the hardware installation. It will be easier to see if you imagine the shutters closing over the window.

For starters some of the slidebolts were installed on the wrong sides. This is the hardware that is located in the middle of the shutters. When the shutters are closed, the bolt on one shutter slides into the catch on the ajoining shutter to securely lock the shutters closed. The slide bolts would need to be mounted to the outer side of the shutter, not to the inside next to the window as shown on the right in this picture.

The other error that we noticed in looking at this picture is that the shutter dogs, also known as tiebacks, were installed a bit unusual. Most shutter dogs are typically designed to be mounted below the bottom outer corner of the shutter in order to hold the shutter steadfast against the wall. Shutter dogs have a "weighted" or heavier bottom side to allow the piece to stay in an upright position to hold the shutter in positon. These shutter dogs were installed on the vertical sides instead. While the shutter dogs may not function properly if mounted this way, it can still be aestically pleasing. Keep in mind though, that we do have offset shutter dogs available which are designed and weighted for side mount installations.