Thermal insulation is the reduction of heat transfer between objects in thermal contact . Technically, thermal insulation is applied so as to reduce heat transfer between the two environments at different temperatures. In properly insulated buildings, it is possible to extend the life of the structure and to provide great gain in heating and cooling expenses .
Largely, fossil fuels are used in order to heat the buildings. Gases arisen from burning fossil fuels as product of combustion cause air pollution and global warming.
Establishing the comfort conditions in accordance with proper thermal insulation methods will result in reduction in energy consumption which will lead to the contribution of preventing global warming and air pollution. Thermal insulation applied in buildings in accordance with the laws and regulations offers many direct and indirect advantages to people and countries. The most important direct advantage is its financial contribution to energy saving.
There are several ways to reduce energy consumption and heat loss. These include ; improving the insulation of the property (reduction of conduction losses), Reducing air leakage and Reducing energy consumption by using efficient heating methods.
For floors, it is important to ensure sufficient insulation between the ground and the floor surface. In new buildings, sufficient insulation is installed during the construction and in older buildings, insulation layers can be laid on existing floor surfaces.
For roofs, the easiest way to prevent heat loss is through insulation of the ceiling in the loft cavity. It is important to put adequate insulation in the loft or ceiling and to ensure that no gaps are left, especially around hatches, electrical and pipework.
To reduce heat loss through windows, the installation of double / triple glazing can significantly reduce any losses. The use of caulking materials around window and door frames can also reduce heat loss.
External walls can basically be insulated in three ways: with external, cavity wall, or interior insulation.
External insulation is the most common and the most effective option. In this case, insulation is applied to the outside of the external wall.External thermal insulation composite systems (ETICS) consist of an insulation layer anchored to the base and a rendering with fabric lining and a finishing coat. In addition to reducing the heating energy requirement, external insulation also solves hygrothermal problems. Because of the higher temperatures on the interior surfaces, condensation and mould formation are avoided.
If the existing external wall is double, cavity wall insulation can be fitted in the space
between the two walls.
Interior insulation is an option primarily used for listed buildings, the façade of which must not be changed. In this case, insulation is applied to the inside of the external wall, i.e. indoors.
Compared to external insulation, interior insulation is trickier as regards the physics of buildings, and less of an insulation effect can be achieved. If materials not open to diffusion are used, an airtight vapour barrier has to be installed on the inside in order to avoid flaws and damages from moisture.
Thermal bridges are areas of the building envelope with more transmission heat loss than elsewhere and with lower temperatures on the inside than in the rest of the structure. If, when the temperature outdoors is low, the inside surface temperature sinks below approx. 13 °C, water vapour will condense in these areas. As a consequence of moisture accumulating, mould can develop in these areas. At the planning stage in a high-efficiency renovation project it makes sense, in connection with calculating the heat energy requirement, to identify all thermal bridges individually,with their lengths and coefficients of thermal conductivity, and while doing so to work out local improvements.
If the building envelope is not airtight, if it has localized leaks, then warm/humid air moves from the interior through the elements of the building envelope. As this air cools down on its way out, moisture can condense in the elements in question and mould can then develop. In addition, such localized leaks cause ventilation heat loss, which in turn impairs the insulation effect of the building envelope.
The heat transferring surface of the building must therefore be implemented with permanent airtight seal.
Airtight and draught-proof implementation has the following advantages:
structural damage is avoided, the thermal insulation takes full effect, airborne sound insulation is effective, ventilation systems are effective, air quality is improved.
Soundproofing relates to the overall ability of a building element or building structure to reduce the sound transmission through it. This type of insulating activity is usually employed when there is a need to keep sound from filtering in or out of the space. Sound insulation techniques are often used in the areas where harmful effects of noise must be avoided (houses, school, hospital, dormitory, hotel, workplaces, etc.), the noise spread to the environment must be prevented (generators, hydrophores, central heating systems , etc ), or in businesses where loud noise is deliberate and intentional (cinemas, theater halls, concert halls and conference rooms, recording studios etc.). Sound or noise is an energy type diffused through vibrations in gases, solid matters and fluid atmospheres. Two types of sound insulation might be referred to – airborne sound insulation and impact sound insulation.
Air-originated sound transmission: Sound waves move inside air and induce construction elements to vibrate. These vibrations travel through the structure or building and are radiated out the other side albeit at a reduced volume.Airborne noise is transmitted through the air and atmosphere like music and speech such as; people talking, TV noise, dogs barking etc.
Impact noise occurs when an object collides with another object. The impact causes both sides of the building element to vibrate, generating sound waves. Examples include dropping objects, jumping, doors banging, walking and furniture moving etc.
Different methods are used to eliminate airborne and impact sound transmission.
When a sound wave strikes one of the surfaces of a room, some of the sound energy is reflected back into the room and some penetrates the surface. Parts of the sound wave energy are absorbed by conversion to heat energy in the material, while the rest is transmitted through. The level of energy converted to heat energy depends on the sound absorbing properties of the material.
Reducing sound transmission requires more mass or a separation of elements. Mass can be increased by using a thicker version of the same material or by using a denser material.A range of factors need to be considered when selecting, installing or detailing noise control in wall, floor and ceiling assemblies. All elements selected should contribute to sound insulation.
Water and Damp Insulation
Waterproofing is the process of making a building structure impervious to water to elongate the building`s life span ensuring the durability and stability of its components . Waterproofing is done to the exterior , interior, roof and foundation of the building. It is one of the most critical part of building construction as water leaks alter with the resistancy of the buildings.There are many causes and locations of leakages in a building. Broken pipes, hoses, improper construction, improper waterproofing, structural cracks and several such issues are major causes of leakages. Leakages can cause dampness and this in turn encourages the growth of molds, microbes, and many other organisms which could be harmful to human health. Asthma, allergies and other respiratory disorders can be experienced as a result of poor quality of the environment.
Apart from health issues leakages can cause flaking and blistering of paints, cracking of structures, etc. which can seriously harm the health of the building and its inhabitants.
As for the financial aspect , the problem will lead to major costly repairs and depreciation of the property value.
Additionally, leakages can cause corrosion of the structure of the building. Typically, the metal components outside buildings are more subjected to atmospheric conditions and corrosion. But corrosion doesn’t stop there. It has infamously corrosive effects on all the metal elements, including those used inside buildings, in the foundation and structural walls.On the other hand, implementing some simple yet effective preventative maintenance activities, such as inspecting and re-coating metals with corrosive resistant coatings on a regular basis, can prevent corrosion damage before it happens. Not only do these coatings help avoid corrosion; they also reduce the extent of damage when it does occur.
It is necessary to have a leak-proof and damp-proof building to avoid losses and harms.
This involves such measures as using water-resistant construction and finishing materials like concrete, closed cell insulation, bricks, wall and floor tiles, aluminium and steel window- and doorframes, glass, etc.
The emerge of heat during fire may cause buildings to be partly or wholly damaged and ruined. Temperature inside the building on fire reaches extremely high levels in a short time and thus, affects the durability of the parts carrying the structure. In case of fire inside a room, temperature rises to the ceiling from the ground (through rise of hot air). After a while, temperature rises to the level of 1000°C on the ceiling. Since durability of ferroconcrete materials decrease at the ratio of 1/3 over 500°C, ceiling has the risk of being collapsed. The structure may collapse and become useless due to the effect of heat which will cause loss of life or property since partial collapse/ demolition will prevent access to the building. Load bearer parts of the building to maintain their functions has a vital importance.
To prevent load bearer structure to be affected from the heat arisen from the fire, all cladding and backlayment components should have low heat conductivity and either be fireproof or be coated with fireproof materials. By insulating against fire; the increase of temperature is slowed down and provides time to the people inside the building to get out and firefighters to take the fire under control. Buildings and structures are divided into highly resistant areas of manageable risk compartments to restrict damaging effects of fire to create safe escape areas. Fire and smoke are prevented from reaching these compartments through the insulation of the walls, ceilings and floors. Doors and windows in these sections should be equipped with certain fire resistance properties. Roofs and facades must be insulated against fire to keep the buildings intact and load bearer structures to remain fire free during the fire till the fire is extinguished. Boiler rooms etc. should be insulated to prevent smoke and flame spread, ventilation channels should be insulated to prevent spread through air ducts and also areas of conduits must be insulated against fire to limit the spread .
Fire insulation begins at the stage of design. Firstly, precautions related to fire safety are determined according to the characteristics and quantities of combustible matters inside the building. Number of people inside the building is determined and risk assessment is conducted depending on intended purpose of the structure. Based on such risk assessment, fire reaction (EI/E) of the walls, ceiling and floors of the structure is determined. Systems consist of mgo boards , glass wool (white), rock wool etc which are fire-proof (Class A) and have high resistance to heat transmission are used to build fire insulated walls, ceilings, floors, ventilation channels. Special fire rated mastics are used in joints, cracks, holes, around pipes/conduits/cable trays on walls, floors and ceilings and precautions are taken in order to prevent spread of flame and smoke. Fire escape routes must be constructed with fire rated materials and fire rated doors. Doors and gates along escape routes must be appropriately marked.
Passive fire protection is built into the structure of a building to restrict the growth and spread of fire allowing occupants to escape and offering protection for firefighters and furthermore protecting the building structure thereby ensuring it’s sustainability