What is an Astragal?

Mary McMahon
Mary McMahon

An astragal is a type of molding which can be used for everything from decorative purposes to creating a tight seal between two doors. Astragals are among the simplest of molding profiles, and they appear in many different types of design and aesthetic schools, sometimes in interesting variations. Companies which manufacture molding typically make astragals, and it is also possible to cut this molding by hand for specific projects.


Viewed in cross-section, an astragal consists of a half round of material, sometimes known as a bead, with a flat strip known as a fillet on either side. Astragals are sometimes called bead molding or half-round molding because of the distinctive bead in the molding, and the bead itself can be carved and decorated. Some notable examples of astragals can be seen in many works of classical architecture, and this molding is also used extensively in framing and ornamental molding for furniture.

On a pair of doors, an astragal is installed to promote the formation of a smooth seal. The astragal makes the door more weather tight, and also assists with fire and sound resistance. The molding is fitted to one of the doors so that it overlaps with the other when the doors are closed. Astragals may also be installed under doors to create a lip which will also help to buffer noise and create a good door seal.

This type of molding comes in a range of sizes and materials including many kinds of wood along with plaster and plastic. When used decoratively, an astragal can add texture and depth, and it may relieve an otherwise boring or bland visual experience. Astragals can also be used to create a smooth lip which will smooth out sharp edges, reducing the risk of injury from objects like cabinets and furniture. This convex molding typically comes in flat strips which are designed to be mounted flush with a surface.

Installing moldings is usually not very challenging. It is important to make sure that the molding is level when it is installed, and if it is necessary to connect two pieces of molding to cover a full length, the join should be made in an inconspicuous place. The surface below should also be prepared with sanding and filling as necessary to make sure that it is smooth and even so that the molding will sit properly. Taking the time to ensure that the molding will be flush will ensure that it will look attractive.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


@cardsfan27 - Oddly enough, my wife wanted to buy new cutlery last weekend and took me with her. I remember that one of the sections had astragal flatware. I didn't know what it meant at the time, but now that I think of it, they all had a round, raised section on them.

The thing that brought me here specifically was that I have been looking for different ways to make a wood astragal design for a project I am making. I am working on a couple of wooden patio chairs right now, and I really think an astragal bead on the edges would look good.

I have the router to do it, I am just curious if anyone has any suggestions about the bet bit to use.


I think an astragal really adds a nice, subtle touch to a lot of different designs. One place I can think where it is often used is on decorative columns. Usually around the top or bottom, there is a small raised section that I am pretty sure would be classified as an astragal. I am sure there are some other good examples where astragals are used, but I can't think of any more off the top of my head.


@matthewc23 - We actually used an astragal seal around the back entry doors of our house. We have two French doors back there, and wanted to try to keep as much street noise as we could out of the back, since that is where the dining room is.

Basically, the way it works is that the trim just goes along the edge of one of the doors, and once they are closed, it overlaps with the edge of the other door and closes the crack between them. I don't really know how well it works, since I have never heard the sound that comes through the doors without the trim.

I don't know whether you could really use that method unless you did have two doors coming together. I guess you could do it with a single door, but I don't know how much of an effect it would have.


I never knew what the technical name for it was, but I really like the astragal look on cabinets. I guess I hadn't really though about it, but I guess it is kind of common around doors, too.

I think it is always nice when something like molding or trim can also serve a purpose, like soundproofing in the case of using astragal moulding.

Has anyone here ever used astragal trim around a door? I am curious how effective it is about keeping out noise, and exactly how it works. I'm not sure I completely understand the say it fits together.

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