A crown post is a term in traditional timber framing for a post in roof framing which stands on a tie beam or collar beam and supports a collar plate. [1] Historically, crown posts were called king posts, but this usage is confusing and obsolete. A crown post is designed to be in a compression and transfers weight to the tie beam, where a king post is designed to be in tension and supports the tie beam. In the U.K a crown strut is similar to a crown post but does not carry a plate.
The use of crown post roofs became prominent in medieval England, particularly during the late medieval period. These roofs were commonly found in high-status buildings such as manor houses and large farm structures, where they provided both structural support and aesthetic appeal. One of the most famous examples is the crown post roof at Old Soar Manor, which showcases the typical design used in the 13th century. [1]
Crown posts were part of a broader European timber-framing tradition that saw variations across regions. In France, for example, the crown post system was studied in detail by the 19th-century architect Eugène Viollet-le-Duc in his Dictionnaire raisonné de l’architecture française. Viollet-le-Duc's work provides an essential historical and technical account of how these roofs were constructed during the 11th to 16th centuries. [2] In Germany, similar systems were employed, though local variations in roof framing techniques led to different structural forms, such as the use of queen posts or hammerbeam roofs. [3]
The design of crown post roofs was essential in distributing the weight of the roof evenly across the structure. The post itself is always in compression, transferring the load directly to the tie beam, thus providing additional stability and allowing for wider spans than would be possible with simpler designs. [4]
Today, crown post roofs are recognised as an important architectural feature of the medieval period, with many surviving examples protected under heritage conservation laws in the U.K. and elsewhere. Restoration efforts often focus on preserving the original timber framing while ensuring structural safety using modern techniques. [5]
Eugène Emmanuel Viollet-le-Duc was a French architect and author, famous for his restoration of the most prominent medieval landmarks in France. His major restoration projects included Notre-Dame de Paris, the Basilica of Saint Denis, Mont Saint-Michel, Sainte-Chapelle, the medieval walls of the city of Carcassonne, and Roquetaillade castle in the Bordeaux region.
Post and lintel is a building system where strong horizontal elements are held up by strong vertical elements with large spaces between them. This is usually used to hold up a roof, creating a largely open space beneath, for whatever use the building is designed. The horizontal elements are called by a variety of names including lintel, header, architrave or beam, and the supporting vertical elements may be called posts, columns, or pillars. The use of wider elements at the top of the post, called capitals, to help spread the load, is common to many architectural traditions.
Notre-Dame de Paris, often referred to simply as Notre-Dame, is a medieval Catholic cathedral on the Île de la Cité, in the 4th arrondissement of Paris, France. The cathedral, dedicated in honour of the Virgin Mary, is considered one of the finest examples of French Gothic architecture. Several attributes set it apart from the earlier Romanesque style, particularly its pioneering use of the rib vault and flying buttress, its enormous and colourful rose windows, and the naturalism and abundance of its sculptural decoration. Notre-Dame also stands out for its three pipe organs and its immense church bells.
The Château de Chambord in Chambord, Centre-Val de Loire, France, is one of the most recognisable châteaux in the world because of its very distinctive French Renaissance architecture, which blends traditional French medieval forms with classical Renaissance structures. The building was constructed by the king of France, Francis I.
A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are typically made of stonework or brickwork, or else of timber structures with metal cladding, ceramic tiling, roof shingles, or slates on the exterior.
A truss is an assembly of members such as beams, connected by nodes, that creates a rigid structure.
A merlon is the solid upright section of a battlement in medieval architecture or fortifications. Merlons are sometimes pierced by narrow, vertical embrasures or slits designed for observation and fire. The space between two merlons is called a crenel, and a succession of merlons and crenels is a crenellation. Crenels designed in later eras for use by cannons were also called embrasures.
Timber framing and "post-and-beam" construction are traditional methods of building with heavy timbers, creating structures using squared-off and carefully fitted and joined timbers with joints secured by large wooden pegs. If the structural frame of load-bearing timber is left exposed on the exterior of the building it may be referred to as half-timbered, and in many cases the infill between timbers will be used for decorative effect. The country most known for this kind of architecture is Germany, where timber-framed houses are spread all over the country.
A hammerbeam roof is a decorative, open timber roof truss typical of English Gothic architecture and has been called "the most spectacular endeavour of the English Medieval carpenter". They are traditionally timber framed, using short beams projecting from the wall on which the rafters land, essentially a tie beam which has the middle cut out. These short beams are called hammer-beams and give this truss its name. A hammerbeam roof can have a single, double or false hammerbeam truss.
A cruck or crook frame is a curved timber, one of a pair, which support the roof of a building, historically used in England and Wales. This type of timber framing consists of long, generally naturally curved, timber members that lean inwards and form the ridge of the roof. These posts are then generally secured by a horizontal beam which then forms an "A" shape. Several of these "crooks" are constructed on the ground and then lifted into position. They are then joined together by either solid walls or cross beams which aid in preventing 'racking'.
A tie, strap, tie rod, eyebar, guy-wire, suspension cables, or wire ropes, are examples of linear structural components designed to resist tension. It is the opposite of a strut or column, which is designed to resist compression. Ties may be made of any tension resisting material.
A purlin is a longitudinal, horizontal, structural member in a roof. In traditional timber framing there are three basic types of purlin: purlin plate, principal purlin, and common purlin.
A king post is a central vertical post used in architectural or bridge designs, working in tension to support a beam below from a truss apex above.
A collar beam or collar is a horizontal member between two rafters and is very common in domestic roof construction. Often a collar is structural but they may be used simply to frame a ceiling. A collar beam is often called a collar tie but this is rarely correct. A tie in building construction is an element in tension rather than compression and most collar beams are designed to work in compression to keep the rafters from sagging. A collar near the bottom of the rafters may replace a tie beam and be designed to keep the rafters from spreading, thus are in tension: these are correctly called a collar tie.
A timber roof truss is a structural framework of timbers designed to bridge the space above a room and to provide support for a roof. Trusses usually occur at regular intervals, linked by longitudinal timbers such as purlins. The space between each truss is known as a bay.
A post is a main vertical or leaning support in a structure similar to a column or pillar, the term post generally refers to a timber but may be metal or stone. A stud in wooden or metal building construction is similar but lighter duty than a post and a strut may be similar to a stud or act as a brace. In the U.K. a strut may be very similar to a post but not carry a beam. In wood construction posts normally land on a sill, but in rare types of buildings the post may continue through to the foundation called an interrupted sill or into the ground called earthfast, post in ground, or posthole construction. A post is also a fundamental element in a fence. The terms "jack" and "cripple" are used with shortened studs and rafters but not posts, except in the specialized vocabulary of shoring.
The Altarpiece of Alella is an altarpiece by the Catalan architect Antoni Gaudí that is part of the project of the chapel of the Holy Sacrament commissioned in 1883 by the Rector Jaume Puig i Claret for the parish church of Sant Feliu in Alella. It became known by a drawing preserved in the parochial archive found in 1959, delineated with India ink in two colours and showing Gaudí's signature, published for the first time in the same year. A reproduction was included the book Gaudí by George R. Collins the following year which was transcendent for the worldwide diffusion of the work of the architect of Reus as it was the first monograph dedicated to him in English language.
The Louvre Castle, also referred to as the Medieval Louvre, was a castle begun by Philip II of France on the right bank of the Seine, to reinforce the city wall he had built around Paris. Over time, it was expanded but was generally demolished above ground in stages between 1528 and 1660 to make way for expanding the Louvre Palace, while some parts of the castle's foundations were incorporated in construction of the later palace.
The Spire of Notre-Dame de Paris is located above the cross-section of the cathedral's transept. Notre-Dame de Paris has had three timber spires made of oak, known as flèches. The first was built between 1220 and 1230. It eventually became so damaged that it was removed in the late 18th century. The second was put into place by the French architect Eugène Viollet-le-Duc in 1859, and destroyed in a major fire on 15 April 2019. Work to construct a third one started in 2022, and was completed when the new copper rooster wind vane was placed on top of the new spire on 16 December 2023, and the third spire was unveiled on 13 February 2024.
A pointed arch, ogival arch, or Gothic arch is an arch with a pointed crown meet at an angle at the top of the arch. Also known as a two-centred arch, its form is derived from the intersection of two circles. This architectural element was particularly important in Gothic architecture. The earliest use of a pointed arch dates back to bronze-age Nippur. As a structural feature, it was first used in eastern Christian architecture, Byzantine architecture and Sasanian architecture, but in the 12th century it came into use in France and England as an important structural element, in combination with other elements, such as the rib vault and later the flying buttress. These allowed the construction of cathedrals, palaces and other buildings with dramatically greater height and larger windows which filled them with light.