Introduction comparative study of masonry. The case study

Introduction

 

1.1  Case
study

This report is a
comparative study of masonry. The case study that I chose to further study on
is the Beverley Minster, a substantial and assertive Gothic church located in
the East Riding of Yorkshire. Architecture played a very important role for the
church in Medieval England. The more splendid the architecture, the more the
church believed it was praising God.

 

fig.1 Beverley
Minster West front

 

Beverley Minster

1.2

The church is composed of three parts,
choir and transepts (c. 1225-1260), nave (c.1308-c. 1370), and west façade
(c.1380-1420). It contains components of three gothic styles – early English,
decorated and perpendicular all combined into a harmonious conclusion.  A magnificent example is the continuous
vaulting from end to end.

fig.2 Beverley Minster

fig.3 Beverley Minster

1.3

On the approach to Beverley, the slender
twin west towers of the Minster stand high above the flat surrounding
countryside. Special points of interest on the exterior are the west front and
the Highgate door, both considered to be exceptional examples of the
Perpendicular style. These formed the inspiration for the present west towers
of Westminster Abbey, designed by Nicholas Hawksmoor.

1.4

The layout of the Minster conforms to that
of most medieval cathedrals and large churches. Starting at the west end and
proceeding east there is the nave, transept, choir, sanctuary and retro quire.

Two features of the Minster are unusual: there is a second transept near the
east end and the main transept has aisles on both the east and west sides.

 

Fig. 4 ground plan of Beverley minster

1.5

The Minster was built in the period
1190-1420. The east end up and including the main transept is largely Early
English, typified by pointed arches, lancet windows, stiff-leaf decoration,
dog-tooth moulding and Purbeck ‘marble’.

Construction

2.1

The stone used throughout is
limestone, mostly from Tadcaster near York. It is light in colour, giving the Minster
a bright, luminous aspect not often found in medieval buildings. Especially at
the east end, there is a considerable use of black Purbeck ‘marble’ (actually
not marble but a hard limestone from Dorset) in shafts and columns.

2.2

The limestone blocks were extracted at Tadcaster
and transported 41 miles on a cart to Beverley. The quarries at Tadcaster were
also used to provide the blocks for York Minster nearby.  As with all constructions, the quality of the
workmanship, and particularly the mortar affects the durability and life of the
building. Though there are several other factors to be considered as to why
construct Beverley Minster with limestone block.

 

2.3

 

The roof
structure on the Minster is highly complex and has changed several times over the
years. Attached at Appendix A is a drawing of a typical roof joint used at the
time of construction.

 

fig.5 roof
workshop of Beverley minster featuring the large

treadmill.

 

Masonry

 

Advantages of
Limestone Block Masonry Construction

 

fig.6 limestone
wall

 

3.1

 

Through the ages but
particularly medieval times, religious buildings of such magnitude were often
built with masonry such as limestone block. The desire to use this particular
limestone was undoubtedly economic and the ready availability of raw materials.

There are two main types of sedimentary stone used in masonry work, limestones
and sandstones. Limestone is still quarried in nearby Lincolnshire to repair
buildings such as the Houses of Parliament.

 

3.2

 

Limestone is the choice of the stonemason to utilize
their carvery skills. Whilst durable and used for sustainability, Church
designs often changed when under construction. Limestone offered the stone
mason opportunity to carve new designs through the process.

 

3.3

 

Limestone construction provided solidity and a
substantial degree of permanence. Whilst the East Riding of Yorkshire does not
have a history of seismic events, the huge foundations will have been laid on
the Holderness Clay alluvial deposits. Sustained durability given a probably
restricted budget would be prerequisite.

 

3.4

 

Building with Limestone block offers a substantial
protection against fire. It is none combustible and a solid construction. The
mass of the building also offers substantial protection from storm damage.

 

3.5

 

The design process for
religious constructions undoubtedly would have a requirement for acoustic
effectiveness and the use of masonry blocks would have re-emphasized religious
control over the population by the use of imposing material. The use of the
blocks enabled the build of such a huge construction, clearly offering a huge
degree of structural strength but maintaining an aesthetically appealing
concept.

 

3.6

 

Whilst there is a debate on
quarrying and the impact it has on the environment in today’s society, the
Limestone was an effective economically readily available material and quite
clearly made good business sense to utilize these assets in the locality.

 

Disadvantages of Limestone
Block Masonry Construction

 

4.1

 

Extreme weather can cause
degradation of masonry. Particularly the expansion and contraction of the
freeze-thaw cycle which shatters the surface. Beverley Minster has been damaged
on numerous occasions by storms over the centuries. Though main structures
remained intact. The colour of the limestone will be affected over time by
weathering and pollution. Though sandblasting and careful cleaning is available
to resolve this issue.

 

4.2

 

Masonry construction does
not lend itself well to mechanization and requires skilled labour. Time served
skilled stone masons are still the obvious choice for maintenance and repair.

 

4.3

 

Sedimentary rock by its
very complex structure (compression of shale like substances) is not
particularly cohesive and does not react well to oscillation and movement.

Immense foundations would have been excavated and completed to support the
structure.

 

4.4

 

Limestone would have been
expensive both for quarry, transport and designed as opposed to other potential
building construction materials for such a project. Limestone is a porous rock
over time and will absorb moisture. Though modern technology is available to
coat and weatherproof.

 

 

Timber

 

      Advantages of using a
timber construction

 

5.1

 

Timber is a natural,
ecological and sustainable product if reasonably sourced. A material used
through the ages for a range of buildings. It does of cause compliment masonry
structures in terms of certain wall structures, roof systems, and joints.

People have been building with timber for thousands of years. Timber is
continually being grown in our forests and plantations.

 

5.2

 

Using Timber has lots of
advantages. It is none toxic, safe to handle and weathers naturally. Life
cycles of buildings are taken into account when using timber and cost
accordingly.

 

5.3

 

Timber production uses very
little energy in converting the wood in trees to the timber used in a building.

This means that the embodied energy in timber is very low, the lowest of almost
all common building materials.

 

5.4

 

Timber has stored carbon
from the atmosphere and will not be released unless used.

 

5.5

 

Timber is a very good
insulator. It reduces the amount of energy used to heat and operate a building.

Timber is a natural insulator and can reduce energy needs especially when it is
used in windows, doors, and floors. It is easy to work with using the fairly
simple equipment.

 

5.6

 

Locally available or can be
transported easily. Clearly wood is versatile and can be milled to desirable
working lengths and size.

 

5.7

 

Project times will be less as Timber is quicker to work with and reduces
labor costs.

 

Disadvantages of using timber construction

 

6.1

 

The exercise of building in
timber requires more precision and planning than a masonry property. Timber
also needs a procurement process which takes time.

 

6.2

 

External timber is notorious for rotting and prone to decay if not
maintained.

 

6.3

 

Timber is highly combustible and history shows that fire is a real
concern for all Timber constructions.

 

6.4

 

Timber will rot and decay
when exposed to excessive moisture and will follow its natural urge to degrade
if not protected.

 

Concrete

 

Advantages of using
concrete construction

 

7.1

 

Concrete is versatile and
modern. It can be molded and formed into just about anything. It is durable and
also a very effective thermal mass.as it absorbs and retains heat well, keeping
concrete buildings cool in the summer and warm in the winter.

 

7.2

 

Concrete is economical, has
a long life and relatively low maintenance requirements. It is not likely to
rot, corrode or decay. Concrete does not combust which makes it fire-safe and
able to withstand high temperatures. It is also weather

resistant and is a barrier
to insects and rodents. It is also resistant to wind, water rodents, and
insects.

 

Disadvantages of using concrete construction

 

8.1

Concrete has a relatively
low tensile strength, ductility, and strength to weight ratio. It has low
thermal conductivity.

 

8.2

 

Concrete is susceptible to
cracking and may contain soluble salts. This may cause efflorescence and affect
the general appearance.

 

Steel

 

Advantages of steel
construction

 

9.1

 

Structural steel components
are lighter and stronger than weight-bearing wood or concrete products. A
typical weight-bearing steel fabrication is 30% to 50% lighter than a wooden equivalent.

This makes steel frame construction far stronger and more durable than
traditional wood framed alternatives.

 

9.2

 

Steel
studs are available in a variety of sizes and can be fabricated order. This
means they can be customized to bear specific loads in buildings of all
different types and sizes.

 

9.3

 

Steel frame construction
reduces the fire risk to a building and retarding the spread of a fire should
one occur. Special flame retardant coatings act to increase this property of
structural steel. However, it will burn after reached a certain level of heat.

 

9.4

 

Structural steel components
are immune to the degrading effects of burrowing insects and mammals, which can
cause a problem for wooden framework unless adequately treated.

 

9.5

 

Steel
can be reused and recycled repeatedly without ever losing its qualities as a
building material. This unique characteristic gives all steel a high economic
value at all stages of its life cycle which, unlike some other construction
materials, ensures that it is routinely recovered and reused.

 

Disadvantages of steel
construction

 

10.1

 

 

Steel
is not known for its warmth, due to its high efficiency in conducting heat. The
insulation value of walls can be reduced by as much as half when heat is
transferred away through steel studs, which is not great for energy retention.

 

10.2

 

One of the benefits of
using wooden structural components is the ability to adjust them on site. A
component can be cut down to size, nails hammered in to strengthen the join and
so on. This obviously can’t happen with steel.

 

10.3

 

Steel
frame constructions rarely work on their own. They usually require drywall,
sheathing, insulation and supplementary wooden components to bring a building
together. Maintenance cost of a steel structure is very high due to the action
of rust in steel and expensive paints are required to renew time to time.

 

11. Conclusion

 

11.1

 

The overall purpose to build
Beverly Minster was to achieve an imposing religious building that was to serve
God and ensure the people were aware of the power of the church.

 

11.2

 

To build an immense Church the size
of Beverley Minster given the available resources at the times of construction
could only be Limestone block offering longevity, durability and value for
money. The stonemason could readily carve and design each block on site.

11.3

 

After researching the potential
alternatives, steel and concrete were not readily available at the time of
construction and even today, would not achieve the distinct imposing effect and
colorization of blocked limestone. 
Timber construction inside the roof compliments the Limestone block,
however, Timber could play no part in the structure of the walls.

 

11.4

 

A timber frame of that size
would not be able to fix the foundations and offer support and permanence. Fire
risk and storm damage are also clear risk factors for such a construction and
emphasize the requirements for such a build bearing in mind the objectives for
durability and cost, the only build consideration could be Limestone block.