The roof truss - the structure that carries the roof covering, tiles, shingles, sheeting and protects the building from the elements - is one of the most important elements in the structure of an architectural work and, at the same time, the least recognisable and often underestimated.

Few people know that the trusses were first prepared on a specially leveled, earthen platform, usually located next to the construction site. Appropriately cut pieces, joined with specially cut joints, were provided with a special system of differentiated marking, incised with an axe, hatchet or chisel. The whole thing was then dismantled, the individual elements were hoisted onto the church walls and reassembled there according to the incised markings. The master carpenter was highly paid, working under a written contract in the nature of a work contract. For erecting the trusses on top of the building, he and his journeymen received a special allowance for working in dangerous conditions.

Maciej Warchoł's book is an exceptional item in the publication series of the Polonica Institute "Studies and Materials". It presents the heritage of technical thought - knowledge of constructions with centuries of tradition. It is enough to look at the inventory drawings and photographs made by the Author to realise how clear and light the 16th century structure over the presbytery is, and how complicated, in terms of shape and size, the construction of the 18th century tower helmet is. The colourful drawings with chronological stratification show the professionalism of the Author. Survey work not only requires the right knowledge and skill to make such measurements. This skill must be accompanied by the courage to move around narrow elements in the knowledge that below there are several or several metres of open space without protection. Published in two languages, the book contains a valuable, unique Polish-Ukrainian and Ukrainian-Polish dictionary of carpentry terminology.

The presented book is important for yet another reason. The great Polish cathedrals, but also other mighty and centuries-old churches, were severely affected by the cataclysm of the Second World War. The cathedrals in Gniezno, Poznan, Wroclaw and Warsaw were burnt down as a result of the deliberate action of either the German army (in Warsaw) or the Red Army (in Gniezno and Wroclaw). The trusses of these cathedrals have not been studied or documented, and will not be able to provide comparative material for other studies.

The Lviv Cathedral is the first large church of the ancient and modern Republic to have a full, scientific documentation of all its carpentry roof structures. Moreover, the research that this book presents is a certain secret knowledge that is available to a rather narrow circle of researchers and an equally small audience. We are keen for this secret knowledge to cease to be so hermetic that it should reach conservationists, other researchers - not only in Poland but also in Ukraine - and sensitise them to an important component of an architectural work whose historical and monumental value cannot be overestimated, let alone its utilitarian value.

Author: Maciej Warchoł

Language editing: Iurii Tkachuk, Grażyna Waluga

Translation: Iurii Tkachuk, Grażyna Waluga

Year of publication: 2021

Number of pages: 220

Cover: Soft

Format: A4

ISBN: 978-83-66172-45-6