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.