Metoda badawcza w rozpoznawaniu przyczyn i stopnia zniszczenia konstrukcji dachowej w zabytkowym neogotyckim XIX-wiecznym kościele św. Marcina w Krzeszowicach autorstwa Karola Fryderyka Schinkla

2011

Nr 1(28)

Historical outline

was built with the use of stones and bricks as a single-nave

church on the layout of a Latin cross closed with a polygo-

nal chancel. The front facade, pedestals, the rose window

above the entrance, cornices, window frames, traceries

and some details of interior decoration were built of stone

(sandstone) and they demonstrate excellent workmanship.

The external walls were built of bricks with charac-

teristic buttresses and two towers with octangular spires

and a decorative viewing terrace between them. The nave

is covered with a pointed ribbed groin vaulting with lu-

nettes. The church has pointed windows with neo-Gothic

traceries and one of its characteristic features is a stone

attic with an ogival motif on arcade cornice.

Above the nave there is a gable roof with a gradient of

18° and a polygonal (pentagonal) one above the chancel.

When looked at from the man’s eyes’ level the roof is not

visible as it is concealed by the attic. The roof framing is

made from different species of conifers (spruce, pine and

larch) with the original strutting beam structure with full

roof boarding for copper sheets [1, 2].

Małgorzata Mełges*, Hubert Mełges**

Research method in recognizing the causes

and level of destruction of the roof construction

in the neo-Gothic 19

century St. Martin’s Church in Krzeszowice

The St. Martin’s neo-Gothic parish church in Krzes-

zowice (Little Poland Province) has been preserved in an

unchanged condition until today. The church was built

thanks to the artistic patronage of Count Potocki – the

owner of Krzeszowice holdings who decided to build the

church and very carefully selected the best design concep-

tion. The ﬁrst drafts of the design of the church were made

by two excellent Parisian architects Percier and Fonteine.

The ﬁnal design, however, which was the basis for build-

ing the church was made by a famous architect from Berlin

Karl Schinkel. In 1832, the design was approved and the

construction of the church without its interiors was com-

pleted in 1844. It was another architect from Berlin and his

student Wilhelm Hofbauer who was the direct builder and

executed Schinkel’s vision. The works, including the fur-

nishing of the interiors, were completed in 1872. Over the

period of about 140 years the church has been used with-

out any problems despite the fact that since its erection the

number of people living in Krzeszowice has grown a few

times. The church is on the permanent conservation list. It

Current condition of the church

The general condition of the church building, with the

exception of the roof framing, is good (assuming the nec-

essary maintenance works are conducted). The result of

different destructive exposure to which the roof framing

has been subjected over about 150 years is a serious tech-

nical and biological decapitalization. In order to deter-

mine the condition and degree as well as the reasons of its

destruction a number of special tests have been conducted

and a number of expert opinions have been made.

Cracow University of Technology, Faculty of Architecture, Institute

of Construction Design.

Cracow University of Technology, Faculty of Architecture, Institute

of Urban Planning.

266 Małgorzata Mełges, Hubert Mełges

Program of tests

The basic criterion of evaluation was the necessity to

make a survey of the roof framing indicating its decapital-

ized fragments. The survey was the basis of further works

such as statistical and strength analysis aimed at determin-

ing the safety of construction elements of the roof fram-

ing with conclusions and recommendations regarding the

necessity to save the building from unpredictable conse-

quences of such loads as e.g. of snow, ice, wind, etc. In or-

der to get the full picture of the damage of the roof framing

it was necessary to conduct phytopathological, entomologi-

cal and mycological tests [3].

After conducting expert evaluations and thorough analy-

sis it was possible to determine the scope of threats and their

origin. This was the basis of conclusions as to the method

and effectiveness of corrective actions regarding the histori-

cal roof framing. All tests and expert evaluations evidently

indicated a very serious technical destruction and extensive

damage of the biological loadbearing structure of the roof

framing. The wood samples which were taken for analysis

(phytopathological, entomological and mycological tests)

demonstrated a huge degradation caused by the destructive

activity of insects – mainly old-house borer, deathwatch and

wood-rotting fungus (Poria vaporaria). The condition of

damaged construction elements, sheathing and rooﬁng in-

dicates that the loss of structural strength of those elements

exceeds 60% and they should be either repaired or replaced.

Otherwise and in the case of additional unpredictable expo-

sure to the elements the roof might collapse.

Selected examples of survey measurements

One of the characteristic features of historical sacred

buildings is their individualism. This is the surveying

method which was applied in the case of the St. Martin’s

church in Krzeszowice.

Firstly, new surveying methods should be mentioned.

They apply CAD, photogrammetry and laser scanning in

measuring historical and contemporary architecture, tech-

nical infrastructure and industrial installations. Engineer-

ing geodesy and photogrammetry have been employed for

years in performing comprehensive architectural surveys.

The measurements were taken with the use of a reﬂector-

less tacheometer (close range surface measurements of e.g.

walls), e.g. semi-metric camera to make ortophotoplans.

At present as a result of the digital technology develop-

ment new measuring devices have been developed such as

lasers and laser scanners, in particular with the use of 3D

measurement technique (vector ﬁle with refraction line-

sand a grid of points). These tools take measurements of

hundreds of thousands of points, recording the geometry

of large objects. Despite their great capabilities the new

measuring devices do not perfectly render the reality of

objects (e.g. the ‘edge sliding effect’ which ultimately gen-

erates a corrupt measurement). It is true that the use of new

photogrammetric technology in taking measurements in

connection with a laser scanner, visualizations and anima-

tions inﬂuence the duration and effectiveness of the meas-

urement work. When deciding to use the new generation

equipment, one should analyze the object and a possibility

to get with that equipment to the place of measurements.

Nowadays, the application of the above-mentioned meas-

uring methods is required. There are, however, situations,

especially in historical objects when making manual draw-

ings and measurements is more useful (especially in the

case of inaccessible and concealed places).

The method of performing the architectural survey of the roof framing

of the church in Krzeszowice

The nave and the pentagonal chancel are covered

with a pointed ribbed groin vaulting above which there

is a strutting roof framing system with a very unusual

construction. The shape of the vaulting and the location

of roof trusses in relation to it created a limited acces-

sibility of the place needed to take measurements with

the use of new generation equipment. Some places

needed for the inspection of the construction system as

well as to make drawings and measurements were practi-

cally inaccessible or at best one needed to crawl to get

there.

The unusual character of woodwork solutions as well

as geometry required a precise manual measurement.

In order to make a drawing of the roof framing of the

church the following were performed ﬁrst: a detailed sur-

vey of the church ﬂoor plan at ground level, cross and

longitudinal sections with views of the church interior,

plan of the vault above which there is a roof framing,

cross sections of the roof framing with views of special

main trusses and plan of the ﬁfth elevation that is of the

roof with gradient of planes and water drainage system.

The other type of performing a survey was photographic

documentation which resulted in the development of so

called research cards. The objective of this type of survey

was to precisely establish the location and type of con-

struction, details and degree of technical decapitalization.

A specially developed method of assigning numbers to

construction elements (trusses and woodwork connec-

tions) corresponding to their speciﬁc location in the plan

and cross sections was applied in each research card. This

Research method in recognizing the causes and level of destruction of the roof construction in the neo-Gothic... 267

Fig. 1. Cross section of the nave of the church

with the view of one of the main trusses

Fig. 2. Initial plans

of the particular fragments

of the church in order to check

the accuracy of measurements

with the use of laser equipment

268 Małgorzata Mełges, Hubert Mełges

Fig. 3. Research Card

Fig. 4. Markings of various types

of main trusses and places

of destruction

Research method in recognizing the causes and level of destruction of the roof construction in the neo-Gothic... 269

method signiﬁcantly facilitated the detection of damaged

places and their scope. Because of very special and unu-

sual joints and woodwork connections, all details required

a careful analysis, inspection and measurement from all

sides with the use of traditional manual technique. What

proved especially helpful in recognizing the complicat-

ed woodwork details was the free-hand sketches drawn

in perspective which helped to precisely reconstruct the

original roof framing. The complicated system of the

main trusses, which were applied in different variations,

required a precise determination of different gradients of

the roof planes above the nave and the chancel as well

as side chapels. The precisely performed survey was the

basis of the design of the whole roof framing replacement.

The bigger interior spaces which were not concealed were

measure with laser equipment; these measurements were

in special cases veriﬁed by manual measurements with

the use of measure tapes. The whole architectural survey

documentation was ultimately made with the use of com-

puter graphic in the following scales 1:50, 1:10 and 1:2.

Color icons of pictures which presented appropriate plac-

es and their degree of destruction were placed on the basic

plans of the location of speciﬁc construction elements of

the roof framing.

Fig. 5. Fragment of roof truss projection with the accepted system of markings in relation to research cards

Conclusions

In conservation works in historical buildings, the basis

for the beginning of any work is the necessary detection

of different details in the scope of damage, repair or re-

placement of necessary elements, etc. The complete and

precisely performed survey is the basis of precise analysis

of different kinds of damage. An architectural survey is

primarily used as a basis for plotting the scale of dam-

age and different types of deformations on it. A good

graphic survey with a photographic survey and other

necessary tests should constitute a concise and compre-

hensive document which is the basis for the determi-

nation of the extent and percentage of damage as well

as for the selection of repair method and estimation of

costs.

References

[1] Baraniewski W., Projekty Karla Friedriecha Shinkla dla Krzeszowic,

Kwartalnik Architektury i Urbanistyki XXVII, 1982.

[2] Baraniewski W., Zespół rezydencjonalny w Krzeszowicach w XIX w.,

[in:] Dzieła czy kicze, Warszawa 1981.

[3] Mierzwa W., Rzonca A., Skanowanie powierzchni, jako nowa

metoda rejestracji i interpretacji szczegółów architektonicznych,

Archiwum Fotogrametrii, Kartograﬁi i Teledetekcji, Vol. 13, Wrocław

2003.

270 Małgorzata Mełges, Hubert Mełges

Metoda badawcza w rozpoznawaniu przyczyn i stopnia zniszczenia konstrukcji dachowej

w zabytkowym neogotyckim XIX-wiecznym kościele św. Marcina w Krzeszowicach

autorstwa Karola Fryderyka Schinkla

W artykule przedstawiono zagadnienie wskazujące, że zabytkowe

budowle sakralne, których stan techniczny i estetyczny uległ dekapita-

lizacji, wymagają opracowania indywidualnego programu badawczego,

szczególnie w takich branżach, jak: architektoniczna, konstrukcyjna,

konserwatorska oraz charakterystycznych specjalistycznych ekspertyz.

Specyﬁką zabytkowych obiektów sakralnych jest ich indywidualizm

wynikający z: okresu powstania (styl), miejsca usytuowania, konstrukcji,

budulca, kubatury i kontekstu klimatycznego. W pracach badawczych

należy przyjąć sprawdzone metody tradycyjne, nowoczesne oraz indy-

widualne metody dostosowane do indywidualnych charakterystycznych

cech budowli. Wyniki opracowania rozpoznawczego są istotną bazą do

przyjęcia prawidłowej logistyki przebiegu wymaganych prac budowla-

nych i konserwatorskich. Należy nadmienić, że obiekty, które zgłaszane

są o doﬁnansowanie z puli Ministerstwa Kultury i Dziedzictwa Narodo-

wego powinny być wnikliwie rozpoznane, w celu dokładnego określenia

kosztów inwestycji. Podjęte działania rozpoznawcze prezentowane są tu

na przykładzie neogotyckiego kościoła św. Marcina w Krzeszowicach

i dotyczą remontu kapitalnego wież i więźby dachowej

Key words: roof framing, decapitalization, reconstruction Słowa kluczowe: więźba dachowa, dekapitalizacja, odtworzenie

Metoda badawcza w rozpoznawaniu przyczyn i stopnia zniszczenia konstrukcji dachowej w zabytkowym neogotyckim XIX-wiecznym kościele św. Marcina w Krzeszowicach autorstwa Karola Fryderyka Schinkla

Małgorzata Mełges, Hubert Mełges

Streszczenie