ABSTRACT
Thermal properties refer to characteristics of a material defining
the substance and related to temperature dependent. The most important
thing in building design is the protection of people who live and work
within the environment. The research work identified some common roofing
materials used for building design in Nigeria..The samples
include aluminium (coated), Zinc and stone coated. The investigation was
done using Ohm‟s law and Frankz Weidman principle. The thermal
properties investigated were thermal conductivity, thermal absorptivity,
thermal diffusivity, thermal resistivity and specific heat capacity.
with the view of establishing their suitability as roofing materials in
building design in Nigeria based on climate and weather condition of
particular location. the results show that zinc has the highest thermal
conductivity, thermal absorptivity, and specific heat capacity and also
the lowest thermal diffusivity and thermal resistivity while stone
coated material has the least thermal conductivity, absorptivity, and
specific heat capacity and also the highest rate of thermal diffusivity,
and thermal resistivity Aluminum coated is within the range of both
sample, with thermal conductivity, thermal absorptivity, thermal
diffusivity, thermal resistivity and specific heat capacity. Thus stone
coated material may berecommended for roofing of building where the
temperature is high and zinc may be recommended for roofing of buildings
where temperature is low. For normal temperature range, Aluminium
material may be recommended.
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Provision of housing among other social amenities occupies a
strategic position in most development plans for developing Nations such
as Nigeria (Chukwucha, and Owate, 2002). One of the fundamental
requirements of buildings is the protection of the people who live and
work within them from hash weather. Thus, objective of environmental
building design is the creation of a comfortable yet efficient internal
environment (Camilleri, 2000).
The design of the building envelope is crucial towards attaining an
optimal configuration, which responds effectively to environmental
changes in order to reduce their impact. The understanding of energy
related characteristics and the evaluation of the relevant properties of
the building envelope is an integral part of every environmental
assessment. Solar energy affects significantly, the interior environment
and the energy requirements of buildings. (Lattimer & Ouelletes
2006).
However, one way to reduce the heat flux is the use of radiant
barriers which reduce the heat flux through radiation. Most building
materials particularly, roofing materials are good conductor of heat.
Materials like metal and tile are commonly used in the form of sheet
metal for roofing in building construction.
The knowledge of thermal properties of different roofing material
is very important in the choice of the type of material to be used in
the construction of a self- cooling or passively cooled building design.
(Etuk, et al., 2008 & Michael, et al., 2008)
However, roofing systems used in the formal and residential sector
are predominantly timber or metal truss systems with tile or profiled
steel roofing, generally these roofing systems will be complimented with
a plasterboard ceiling, regulations which require that these roof
assemblies are insulated.
Therefore, thermal insulation is applied above the ceiling to
achieve the thermal resistance requirements. The requisite thermal
resistance can be achieved by adding additional layers of fibrous loft
insulation or with reflective foil layers to create air-spaces or by
making use of thermally insulating board products.(Safintra roofing and
steel South Africa, 2016).
In the recent observation, it has shown that roofing materials used
in building design doesn‟t take sufficient account of climate and
environmental factors in the design, most especially with the regards to
the choice of roofing materials to be used. These situations would
increase the energy consumption for heating and cooling in buildings and
affects comfort, health and efficiency. Therefore, it is important to
carry out adequate research on thermal properties of these roofing
materials.
1.2 Aim and Objectives
The aim of this research is to measure and compare the thermal properties of some common roofing
materials in building design in Nigeria.