Series of intriguing circle designs found on the underside of a beam
A series of intriguing circle designs found on the underside of a beam in a 17th century house in Oxfordshire © Ron Hammond
A series of intriguing circle designs found on the underside of a beam in a 17th century house in Oxfordshire © Ron Hammond

The Difference Between Apotropaic Marks and Carpenters’ Marks

Carpenters’ marks, expressed in Roman numerals, can be seen in many timber framed buildings. Several of the responses we had from the public were in fact carpenters’ marks, rather than apotropaic marks.

Carpenters’ marks were created with a race knife and used as tags to distinguish various elements of a timber frame and how the entire ensemble should be pieced together. These marks are formed using a straight line often gouged with the u-shaped, or scooped, end of the race knife.

Roman numerals were commonly used to mark up the timber elements of a timber framed building. At their simplest these look fairly familiar, though four is usually represented by IIII, rather than IV. The convention for representing four as IV and nine as IX only emerged as the 16th century progressed and took a considerable time to be universally adopted.

Marian symbols

When we get to the various combinations of letters which seem to be used on timbers then we are into another minefield. A very common type of marking found in older buildings are generally known as Marian symbols, for their supposed association with the Virgin Mary. Often the letters AM, thought to be for Ave Maria, simply M for Mary or VV for Virgin of Virgins are found scribed onto the fabric of early houses and churches. The VV and M markings are particularly common, and could easily be mistaken for an upright or upside down W. These are however difficult to interpret and there is some academic dispute as to their meaning.

The interesting work of Tara Hamling has demonstrated that contrary to what is often thought, it was still acceptable to have images of saints and of Jesus, provided that they were not used as idols to be worshipped. So, an image of Christ as an independent picture which looked like an icon was considered unacceptable, whilst in a secular context on a wall as a part of the general decoration it was allowable.

The changes in attitude to images were complex and changed throughout the 16th century as the theological views on these matters fluctuated. So, in that context the use of the letters AM and similar initials remain somewhat mysterious.

Burn marks

Another intriguing marking, which was not sent in to us in any great numbers but which we know are very common, are the tadpole shaped charring marks to be found on timbers in many early houses and widely described as taper burn marks. These have traditionally been interpreted as the result of tapers attached to the beams to provide light which have burnt down to the point where they have charred the timber.

Practical research has demonstrated that is very unlikely, particularly as these marks have been found in a variety of places throughout buildings, including roof timbers and even hidden beneath floors. This evidence suggests the marks have been made deliberately and may well have been made whilst the building was under construction. The interpretation is to see them as a ritual protection against lightening and fire.


These intriguing marks are very ancient, being recorded as far back as 3000BC. Although in more recent centuries it has become a symbol of evil, during the medieval period it was used to avert it and is thought to have been intended to act as a way to trap evil spirits into the endless line.

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