At the prehistoric age, human beings-built huts in order to defend themselves from environmental factors and other living creatures. They were the first architectural samples. In order to build these huts simple materials, which can be gathered easily from the environment, were used. Afterwards different construction techniques developed and the building materials also improved and evolved. At the beginning, construction and strength of the building were of prime importance and space phenomenon did not developed. After the improvement of new building techniques, interior space gained importance. In order to create an esthetic and durable interior space, some factors had to be taken into consideration. These are environmental effects (heat, water, moisture, noise, light, etc.), mechanical effects and esthetic requirements. The layer which was created to provide these features is called “finishing layer”. Finishing layer has to be esthetic, durable and strong. Also in recent years, ecology of the building and finishing materials has gained importance in order to protect the user health and ecological balance of the world.
2. Interior Finishing Materials
Finishing can be defined as the final layer which protect and fix the surface of the building elements. This layer
plays an important role in visual and psychological definition of interior space. At the period of traditional
building techniques; buildings were usually produced by traditional materials such as stone, wood and adobe.
They were used uncoated or sometimes plastered. After the transition to modern building techniques; the building
section got thinner and new layers had to be added in order to provide comfort requirements. Consequently
finishing layers were needed. The main purpose of finishing layer is to fix the surface. Also it is essential to coat
wall, floor and ceiling in order to create a suitable appearance and to protect the construction from effects of
water, heat, moisture, abrasion.
2.1. Wall finishing
The prior function of wall is to separate spaces from each other vertically, but depending on the structural
system of the building it may also carry loads. Wall has to protect the space against the effects of water, moisture,
heat, noise, light, fire, etc.
Wall section can be analyzed in three layers;
Some walls can be formed by one layer while some of them are formed by three layers. For instance, exposed
concrete is formed by one layer, but brick walls are formed by three layers (Toydemir, Gürdal, Tanaçan, 2000).
Figure 1: Type of wall section
Core is the structural part of the wall and its primary function is load-bearing. At solid masonry buildings,
wall core has to carry all the loads which effect building. At skeleton systems; wall has to carry its own load and
transfer it to the system. Other functions such as; heat, water, moisture, noise, light and fire resistance is shared
by all layers. If a function stands out in design process, an appropriate detail solution has to be created (Toydemir
et al, 2000).
Functions of the coatings can change depending on its position on the wall.
Exterior coating takes a role in forming the architectural character of the building. Also, it has to be resistant to
atmospheric, mechanic and chemical effects and easy to clean.
Interior coating can also be named as interior finishing. It doesn’t have direct contact with water and also doesn’t
come across with great temperature changes; therefore, it doesn’t have heat and water problems. Although the
core solves the problems about noise, finishing has to be porous enough to emit the noise and provide the
acoustic balance. Interior finishing has to be nonflammable, vapor permeable and non-toxic. In addition,
interior finishing has to be compatible with the function of the space by appearance, color and texture
(Toydemir et al, 2000).
Different building materials can be used as interior finishing. Plaster, paint, wood, gypsum panel, sandwich panel,
ceramic, natural stone, artificial stone, glass and metal can be used as wall finishing materials
2.2. Floor finishing
Floor is the horizontal structural element of the building. The prior function of floor is load-bearing. It
increases the strength by connecting the walls in solid masonry systems. At skeleton systems it has to carry its
own load and transfer it to the system. It also has to be resistant to some effects such as; heat, water, moisture and
noise, according to its location in building. Floor’s section can be analyzed in four layers;
structural system and
The most important layer is structural system and the others support it.
Floor and ceiling coatings are finishing layers and have to create a visually and functionally favorable impact
(Toydemir et al, 2000)
Figure 2: Floor Section
Floor coating is the upper layer of the floor. It has to protect the layers below and has to be appropriate with
the function of the space. Therefore, while choosing floor coating; primarily the function of the space and user
requirements has to be determined and the selection has to be made by taking these factors into consideration.
Screed (cement, magnesia, gypsum based), terrazzo, natural and artificial stone, ceramic, glass, cork, wood,
polymers and metal can be used for floor coating.
2.3. Ceiling finishing
Ceiling is the lower part of the floor. If it does not have any equipment, such as HVAC or installation, it is
usually straight and can be solved easily. But if the ceiling has an acoustic, HVAC, lighting or sprinkler system
equipment on it, a suspended ceiling has to be created in order to hide the system (Toydemir et al, 2000).
Suspended ceilings are usually composed by a hanging system and a finishing material. Hanging system is
installed primarily and then the finishing material is installed to the system Hanging system is usually composed
from metal. Finishing material can be gypsum, metal, wood, ceramic, glass, etc.
3. Criterion Required for Interior Finishing Materials
Quality interior design reflects “understated excellence” and assures that facilities are attractive, environmentally
safe, operationally efficient and maintainable. Interior designers must strive for sound, economical, functional,
and aesthetic design achievements. Well-designed facilities satisfy users’ needs, install pride in ownership, and
promote productivity in the workplace.
Functional interior designs ensure that each aspect of an interior environment performs efficiently for its users. A
good working relationship between users and designers will help accomplish this goal. Each facility type presents
unique functional requirements that will ultimately affect the selection of finish materials and furnishings. It is
important that designers investigate all aspects of spatial requirements via the users.
3.2. Cost Effectiveness
All interior selections must reflect the “best buy” for the project in terms of aesthetic value, maintenance
characteristics, and life-cycle costs. Inexpensive, short-term solutions do not necessarily produce cost savings.
3.3. Life Cycle Cost and Appeal
When making selections, designers must consider product performance and longevity of appeal, as well as initial
costs. As the appeal of finish materials degrade, users want to replace them; therefore, products which keep their
appearance and shape longer are better choices even when initial costs are higher.
Durable designs and finishes pass the “test of time.” Designers must be concerned with material durability and
wearability while considering budget restrictions. Selections of quality materials and products must also be
appropriate to the function and level of use of each facility.
The use of easily maintained finishes is critical. While certain finishes may provide excellent durability, designers
must give serious consideration to maintaining the appeal of materials. It is critical that designers be familiar with
finishes that wear well and require low maintenance.
Each installation has its own compatibility plans that reflect regional, environmental, and architectural
considerations. Designers should be familiar with installation plans to achieve unified scales, traditions, and
excellence in facilities.
Flexible designs are essential to meet dynamic requirements. While the primary function of each facility must be
first priority, designers must keep in mind which functions evolve, and which facilities may require future
modifications. Rapid technological advancements often demand upgraded equipment, power and communication
4. Interior Finishing Materials and Installation Techniques
Interior finishing materials visually identify and reflect the character of the space. In this part of the study, the
types, general properties, application techniques of interior finishing materials are discussed.
4.1. Cement-based material
Cement is the most common binding material nowadays. According to various sources; natural cement was
produced BC 7000 and artificial cement was produced BC 5600. But the cement used today is based on 1824
Cement-based finishing materials are composed of mortar by mixing cement, aggregates, and water. They can
be continuous or in tiles. Terrazzo is cement-based continuous material; while cement, terrazzo and concrete tiles
are products in tiles (Toydemir et al, 2000).
Terrazzo floor is formed from a mixture of small stone pieces and cement mortar created from marble flour and
color pigments. When the mixture is ready it is installed to a well leveled screed powder. Installation has to be
done quickly in two layers. The upper layer’s abrasion resistance is higher than the other. Crack detailing is
necessary to prevent the transmission of fractures in the concrete. After it sets the surface of terrazzo is (Toydemir
et al, 2000).
Cement tile, is a layered tile produced from cement, sand and oxide paint. The upper layer is paint. Desired
colors and patterns can be created with the oxide paint. The second layer below paint has a high cement factor;
the last layer is produced from a regular cement mortar.
Cement tile is installed on a well leveled clean surface with adhesive mortar. While positioning the tiles a thin
gap is left for the joint. After the installation, joints are filled with grouting. The terrazzo tiles are formed by white
and colored stones/glass, cement, paint, marble powder and water. It has an abrasion layer of approximately 1 cm
and below that it has a regular mortar layer. It is installed just like cement tile and should be periodically polished
(Toydemir et al, 2000).
Concrete tile is formed by cement, polymeric resin, fine aggregate and water. It is installed with cement adhesive
4.2. Earth-based materials
Earth-based materials are used in the building because they can easily be found since the prehistoric times.
Ceramics which are baked at high degrees are used as the earth-based finishing materials at the building. The
most significant property of the baked earth-based materials is their high heat insulating ability. In addition,
they are light and resistant to chemicals and high temperature. The biggest disadvantage of the material is their
fragility. Ceramics are divided into three groups according to their porosity;
The approximate cooking degree is 900°C for porous ceramics, 1150°C for semi-porous ceramics and 1400°C
for non-porous ceramics. Compression strength of porous ceramic is low when compared to non-porous
ceramic. Therefore, its heat insulation ability is higher. Nonetheless, the compression strength of non-porous
ceramics is quite high. While non-porous ceramics cannot be used for floor coating, porous kinds can be used
both on walls and floorings (Toydemir et al, 2000).
Ceramic is usually glazed to decrease its water absorption and to create a smooth surface. Glaze is composed
by the transition of metal-oxides on the surface of the ceramic. The abrasion resistance of glaze is low and also
its slippery surface reduces the walking safety. Therefore, glazed ceramics should not be used at floors with high
traffic (Riggs, 2003).
Another earth-based material used for interior floor coating is terracotta tile. It is produced by baking a clayrich ceramic dough above 1000°C degrees. Due to its high baking degree it has a low porosity and
impermeability. To increase the adhesion surface, grooves are opened under tiles. They are installed with cementbased adhesive mortar. Joints are left between the tiles and after they are dried grouting is applied (Toydemir et
Glass is used since prehistoric times and it is defined as a kind of ceramic. It had been used for producing
ornaments in prehistoric times. Later it has started to be used as structural purposes. Glass was first used in the
windows to make the connection between interior and exterior spaces. Later, with the emerging technologies,
it has started to be used in large sizes and for different features in different parts of the structures (Binggeli, 2008).
Glass is formed by melting the ingredients together at high temperatures, shaping and annealing of the
material. Usually floating method is used for shaping the structural glass. Glass is used in interior spaces as glass
brick walls, floor tiles and mosaics. Also, glass foam can be used on walls for acoustic purposes.
Glass foam is obtained by treatment of glass components with carbon dioxide. Glass foam is nonflammable, light,
thermally resistant and dimensionally stable. It is used on interior surfaces for acoustic purposes. It is used in
sound studios, shooting ranges and movie theaters.
Metals are resistant and shiny materials obtained from the mines. Metal has a high heat and electric conductivity
due to its regular atomic structure. This also leads to a high compression and tension strength value. The most
important problem about metal is corrosion reasoned from water vapor and oxygen. This can be solved by periodic
painting or using alloys. Alloys are obtained by melting and mixing two or more metals in order to increase the
strength and resistance of metal.
Metal is preferred due to its structural strength and esthetic appearance in interior spaces. It is used as wall
and floor coating material in panel or tile form. Metals can also be used at the ceilings as suspended ceiling
material (Toydemir et al, 2000).
Metal wall cladding panels are usually produced from aluminum in different dimensions. They are installed on
metal profiles. Ceramic-like metal tile and mosaics are produced from stainless steel, copper, aluminum, and zinc.
They are installed like ceramics (Toydemir et al, 2000)
Metal floor coating materials have a high temperature, friction, abrasion and impact resistance. This type of floor
coatings are often used in steel constructions.
Metal can also be used on the ceiling as a suspended ceiling material. It is used at both hanging system and
finishing material. Metal profiles, screws, straps and strips are used for the hanging system. Different sized and
formed metal panels are used as finishing materials.
4.5. Polymers (Plastics)
Plastic is produced by processing carbon (C) with hydrogen (H), oxygen (O), nitrogen (N) and other organic or
inorganic elements. Plastic is not found in nature, but obtained by the treatment of natural elements.
Plastics were firstly produced and used in the late 19th century. The high resistance against environmental
factors, low cost and the unlimited production forms has increased its usage area and production amounts.
Polymers are divided into two groups according to their thermal behavior;
Thermosets doesn’t soften and melt when they are heated, after a certain temperature they begin to break down.
They can only be formed during polymerization. Thermoplastics are solid at room temperature. They soften and
melt when they are heated without breaking down (Binggeli, 2008).
Plastics are used as panels, sandwich panels, ceilings, polymer and epoxy floors in interior space. Polymer
panels can be produced in desired width and color from PVC, acrylic and polycarbonate. They are installed to a
construction system. Sandwich panel is a structure made of three layers. It has a low density core inserted between
two relatively thin layers. It has a high mechanical performance. The sandwich panels are often used in
prefabricated buildings. Sandwich panels are applied in a similar manner with the other interior coating panels
(Toydemir et al, 2000)
4.6. Natural stone
Natural stones are obtained by cutting the solid layer under the soil. It has been used as a structural and coating
material in building for centuries. It is preferred because it is resistant to environmental factors, has a high
abrasion resistance, impact strength and has a low absorption rate. Natural stones are used as wall and floor
coating material in interior space. Two different methods are used in wall installation. At the first method the
material is directly installed to the wall with cement mortar, the second is applied to a metal supporting system.
In interior coatings direct installation is preferred. Porous stone types such as travertine and sandstone has to be
used in order to increase adherence. Precautions should be taken to prevent the stones from falling before the
mortar has hardened (Toydemir et al., 2000; Riggs, 2003).
Natural stones used as floor coating has 2-5 cm thickness. 2 cm tiles can be used in normal floors, 3 cm tiles can
be used in borders and 4 cm tiles can be used in stair coating. Stone selection should be done according to the
circulation of the space. Hard stones such as granite, andesite, basalt, diabase and porphyry should be preferred
in spaces which has high human traffic.
On the other hand in spaces where there is low human traffic, softer stones can be preferred such as marble and
limestone. Installation is made with cement-based mortar. After the coating is dried, grouting is applied to joints
and then polished
Textile is used as carpets and upholstery fabric for furniture and curtains. For this purpose wool, cotton,
linen, leather are used; polymers such as nylon and perlon can also be used.
Carpet is used for floor coating in the residential and working spaces. The carpets are divided in two different
In recent years polymer-based non-woven carpets are preferred for their high sound absorption values and
economic reasons. They are produced in rolls or tiles and applied to the floor with glue.
Woven carpets are made of various threads and they are thicker. This type is applied in the same way with the
non-woven carpets. Dirt can easily penetrate into the material because of its thickness. For this reason woven
carpets are not recommended at places where hygiene is important (Toydemir et al, 2000).
4.8. Wood and wood composites
From the prehistoric times wood is preferred due to its strong, lightweight, easily processed structure. It is
mentioned at various sources that wood has been used for different purposes in ancient Egyptian, Greek, Roman
and Chinese civilizations. It had been used as construction, coating and furniture material in forestry regions; and
in less frequent regions it has been used as door, wall panel and furniture (Riggs, 2003, Williams, 2012)
Wood is one of the most common coating materials in interior space. It can be used in different dimensions
of panels on the wall. Solid wood panels are often produced in 8-12 cm dimensions. They are used in small
dimensions because of the movement of wood. However, it is possible to manufacture large sized composite
wood panels. They can be produced from fiberboard and particleboard Wood floorings are divided into two
groups; tongue-grooved wood floors and parquet floors
Tongue-grooved wood floors are applied by nailing the pieces on furring strips. Parquets are divided into several
groups such as solid wood, and laminate wood parquet.
5. Principle and elements of functional and aesthetical interior design
Professional interior designers will usually follow a set of informal “rules”, based on specific interior design
principles and elements. These interior design elements include space, line, forms, light, color, texture and pattern;
and keeping them balanced is the key to creating an aesthetically pleasing interior.
In addition to enhancing the appearance of a room, getting these elements to work together in harmony will also
bring an increased functionality. To start, an interior designer will assess the room according to these interior
design elements, and then use them to disguise or enhance the various features and flaws of the space. As a
minimum, the following seven elements should always be considered in the creation of any interior.
The foundation of an interior, space is a fundamental concept to understand, ensuring you’re best equipped to
take advantage of what is available to you. The available ‘space’ usually can’t be easily changed (though
sometimes a designer may have the luxury of doing so), so you need to work with what you have within the
physical boundaries of the room.
In interior design we have the luxury of working within three-dimensional space (length, width and height). This
three-dimensional space can be filled or left empty, depending upon what you need to achieve from a functionality
and design perspective.
Horizontal, vertical and dynamic lines help to shape a room and guide the eye. Creating lines using the room’s
furnishings and structural design can form harmony, unity and contrast.
Horizontal lines, give a sense of stability, formality and efficiency. Interior designers highlight horizontal lines to
make a room appear wider and longer, and to draw the eye to a focal point. But be careful, overemphasis of
horizontal lines has the ability to make the space seem boring and uninspired.
Vertical lines, created by features such as windows and doorways, evoke feelings of freedom and strength. On a
functional level, accentuating vertical lines often gives the illusion of a room being taller. Often suited to use in
dining rooms, entries and offices, vertical lines must be incorporated wisely so as not to leave inhabitants feeling
Dynamic lines refer to diagonal, zigzag or curved lines. Such lines can be found in stairs, for example, and
provide energy and movement. Stimulating to the eye, dynamic lines capture our attention longer. However, too
many dynamic lines in one room can be distracting, and overpower horizontal or vertical lines.
Ideally, interior designers will strike a balance with the incorporation of different lines. This is typically done by
selecting one dominant feature line, in accordance with the client’s brief and the desired feeling they wish to
convey in the space.
Form is the shape of the room. In other words, it relates to the physical form of anything that is three dimensional.
Forms can usually be described as either geometric or natural. Geometric refers to hard lines and square edges,
often looking man-made, while natural relates to more organic forms that seem to be created by nature.
Another thing to take into consideration with form is the proportions and scale of the room compare to the objects
being placed within it. Adding forms of similar shapes can create harmony and balance, while adding too many
differing shapes can have a confusing result. A space is typically more pleasing if the dominant form is repeated
in minor objects throughout the room.
Colour is a science all on its own, and is another extremely important element that interior designers. It has the
ability to create mood, define unity and alter the perception of how large or small a space is.
Colour can evoke memories and stir emotions, stimulating a physical and psychological response in our bodies.
For example, greens and blues entice calmness and are suited to bedrooms, whereas red entices appetite and
therefore often features in kitchens.
When considering the colour of a room, first think about what the room will be used for and the activities that
will occur in that space. Secondly, consider how both natural and artificial lighting will affect your selected colour
across the day and night, given that light can alter our colour perception. Finally, consider the size of the
space. Interior designers will often incorporate lighter or brighter colours in smaller spaces to give the illusion of
more space. Darker colours can give a powerful dimension to a larger space.
Color preference is very personal and individual interpretation of color varies widely. However, the true properties
of color are constant. The designer must have knowledge of these properties and their relationship to the
functional, spatial and lighting aspect throughout the space. The designer and the user must separate personal test
from professional design. The following general guidance direct attention to spatial area of consideration when
selecting color schemes.
Provide timeless color coordination that will be attract to the majority of people
Use natural colors of permanent background finishes (e.g. architectural material -ceramic tile stone panel fabrics)
to support variety of color scheme
Vary the intensity of color and create pattern to provide visual relief from the monotony of natural order
Use accent color for finishes that are subjected to periodic change (carpet, wall coverings) and to create interest
of focal point
Use pattern and texture to enhance visual interest
Use color to enhance spatial quality of an area
Use warm color to make a room seem smaller more human in scale warm color appear to advance toward the
Use cool colors to make a room seem larger and more spacious. Cool colors appears to recede from the viewer
Change the perception of a room’s size without construction by varying the placement of horizontal color breaks
When the ceiling is low avoid drawing attention to the ceiling line where it meets the wall
Use fewer color breaks to make a room seem larger
Paint door and frame to match the wall in small room
Avoid accent walls keep wainscot and wall color similar
Make wall a similar color to floor covering
Use pattern and texture to stimulate interest and tie color scheme together
Select solid and small pattern that coordinate with larger pattern
Vary the size of texture to add visual appeal in one color scheme especially when the introduction of new color
is not desirable texture affect the way an object reflect light ;smooth shiny surface reflect light more than rough
Glossy surface are perceived as cold while softer matte finishes are distinguished as warm
Texture has the ability to add interest and detail, making it visually pleasing to the eye.
Texture comes in two forms – visual texture and actual texture. Visual texture refers to texture that is perceived
by the eye. In other words, this is the impression of texture one gets by only viewing an object. This effect is
usually found in the form of pattern. Actual or tactile textures can be seen or felt and has 3D characteristics. For
example, a fluffy, colourful cushion can be appreciated not only with the eye but also with touch
Generally, if there is a sense of something missing in a room, a good interior designer will be able to distinguish
that it will be due to lack of texture. Texture plays a part in every object selected for a room, and therefore is best
managed with careful consideration from the ground up. The placement of each object in comparison to the
texture of the object beside it will also add emphasis and contrast to the finished design.
A pattern is created by the use a repetitive design and can be found in wallpaper, soft furnishings, rugs and fabrics.
Patterns come in various types, such as stripes, geometric, pictorial, organic, motif and animal prints.
When implementing pattern, it’s best to firstly consider the size and style of a room. Introducing pattern in a small
room should be done sparingly, to avoid overwhelming the space. However, as discussed in the element of line,
patterns that create vertical or horizontal lines can be used to give a heightened sense of space. Complex patterns
made up of contrasting colors and lines can liven up a room, however they are best used in the form of a feature
wall. Large scale patterns can flourish in a large space and become a distinct focal point to the room.
In regards to style, it’s vital to know what category the pattern falls into to ensure that the essence of the room is
maintained. For example, for traditionally styled rooms, incorporate organic, floral prints. For a contemporary
touch, geometric and abstract prints should be experimented with.