§ Thermal insulation may be defined as a parries to the natural flow of heat from an area of high temperature to an area of low temperature.
§ In buildings this flow is generally from the interior to the Exterior.
§ The flow of heat through the solid walls of the buildings is mainly by conduction,
§ The amount of heat transmit depending on:-
i. The temperature difference between the two surfaces,
ii. The thickness of the immediate medium,
iii. The area of the exposed materials,
iv. The time of heat flow and
v. The rate of heat transfer of the conductions of the intervening materials.
Factors influencing the flow of heat from the exterior into the interior of the building:-
i. Thermal conductivity of the external walls of the building e.g. Walls, roof and floors
ii Deference of temperature between both the faces of the walls
iii. The area of the external walls of the building.
iv. The total area covered by doors and windows.
v. The rate of air movement through the, enclosed spaces within the building or walls.
Types of insulting materials
There are various types of insulating materials which are describes a s follows :-
Block Insulation
It is made up of cork boards, cellular glass blocks, rubber blocks, mineral wood blocks or wood fibers bound together with cement.
Blanket Insulation
These are made up of flexible fibers materials and are available in rolls and Its thickness varies from 10 to 80 mm.
Batts Insulation
These are soft materials similar of blanket insulations, but are smaller in size and greater in thickness.
Loose fills
The materials like glass wool, wood fibre, slag wool etc are loosely pored into the studding space and other similar spaces.
Economics of thermal Insulation
§ By providing the thermal insulation in the building , considerable expenditure in heating, cooling or air condition is saved.
§ Moreover the temperature inside the building is maintained more uniformly
Note; before fixing a particular type of insulation materials, the economic feasibility should be also considered.
The following factors need careful consideration while considering the economic feasibility of thermal insulting materials:-
i. The cost of insulating material
ii. The cost of placing and fixing the insulation
iii. The education in the cost of heating and cooling
iv. The rescuing expenditure to maintain the standard of insulation.
A CAUSTICS AND SOUND INSULATION
The term “ a caustics” may be defined as the science of sound, and it describes the origin, propagation and sensation of sound
What is sound?
Anything that can be heard is a sound, whether it is made by conversation machinery or walking on a hard surface.
Sound can differ in two important ways,
§ By loudness
§ By pitch.
A sound is produced when the medium enclosing the body is compressed suddenly. A sound travels in the form of wave through certain medium.
when a sound is produced within the building three reactions can occur
i. The pressure or sound waves can come into the contact with the walls floor and ceiling and be reflected back into the building.
ii. Some of the sound can be absorbed by these surfaces and / or the finishes.
iii. The sound waves upon reading the walls, floor and ceiling can set these members vibrating in unison and thus transmit the sound to adjacent rooms .
What is Noise?
A noise can be defined as any undesired sound and may have any one of the following four effects on man:-
i. Annoyance
ii. Disturbance of sleep
iii. Interfere with the ability to hold normal conversation
iv. Damage of hearing.
The approach to solve noise or sound problems can be:
i. Reduce the noise emitted at the source by such dances as mufflers and mounting on resilient pads.
ii. Provide a reasonable degree of sound insulation reduce the amount. of sound transmitted
iii. Isolate the source and the receiver
iv. Provide required standard of walls or floor structures and finish which can reduce sound transmission.
External noise
The main barrier to external noise is provided by the shell or envelopes of the building, the three main factors being:-
i. The mass of the enclosing structure
ii. The continuity of the structure
iii. Isolation by double leaf construction or cavity wall construction when using light weight materials.
Terminologies
Thermal conductivity
Is the measure of materials, ability to transmit hear and Expressed as the head flow in watts per m2
Thermal resistively
this is the ability of a materials, regardless of size or thickness, to resist the passage of heart and is the reciprocal of the thermal conductivity.
Thermal resistance
This is the product of thermal resistant and thickness in metres.
SOUND INSULUTION IN FLOORS
The following floors structures and finisher can be used to reduce the transmission of sound. Refer sketches, Construction technology hand book; author Childley
Concrete floors
Floating timber rafter
Timber floating floors
FIRE PROTECTION:
Fire protection is the protection of the occupants, occupants and structure of a building from the risks associated with fire.
It is practically impossible to eliminate completely the chances of fire in a building as it is a fact that no building materials is fully fire proof.
Characteristics of five- resisting materials
i. The material should be composed of such elements which do not disintegrate under the effect of greeter heat
ii. The materials should have low co- efficient of thermal expansions, so that the excessive expansion of a particular member which may lead structural instability is prevented.
iii. The materials should not contract rapidly when it is cooled with water at high temperature.
iv. The materials should be compact which cannot easily catch fire.
Fire resisting propertied of common building materials
§ Stone
The stone is a bad conductor of heat.
The stone disintegrates into small pieces when is healed and suddenly cooled.
§ Bricks
is a bad conductor of hint and it is rest heat up to 120c0
If the quality of the montar and workmanship are good, the bricks masonry
Resist afire & a greater extend.
§ Timber.
Timber is a bad conductor of heat .
Timber ignites and get rapidly destroyed in case of fire.
§ Steel
Steel is a good conductor of heat and therefore it is quickly heated in case of fire.
§ Concrete
Concrete is a bad conductor.
It can be used as an effective fire resisting materials.
General guide lines for fire proof of the buildings.
Alarm system
This is installed to give an alarm and call for assistance in case of fire. this system may be automatic or normal.
Protection of openings
The openings of the buildings should be well protected.
In case of fire, the inhabitants of the building can come out from these protected openings
Common wall
When a fire- resisting building is located at the site of another building
The common wall should be of a minimum thickness of two bricks.
The common wall should be raise above roof level by at least one meter.
Stairs
Emergency stairs of a ladder should be provided in the fire resisting building. The ladder should made with fire resisting materials with a fire- proof door.
Floors
the floor in such building should be of R.C.C of at least 150mm thickness
the floor should be prowled with out ward slope to drain the water when – fire fighters are working.
Fire extinguishing arrangements
This arrangement depends upon the importance of the building. The commonly used equipment for fire extinguishing equipment:-
i. Manual fire- extinguishing equipment
ii. Internal hydrants
iii. Automatic sprinkler installations
Topic No 4
FLOOR FINISHES
Floor finishes for domestic buildings include a wide range of alternative
The factors that may influence the choice of floor finish depends on the use of the floor space and limits on cost.
The following should be considered for choice of floor finish.
Resistance to Wear
The type of wear that is normal in a specific part of a building so that it lasts many years without replacement.
Resistance to grease and oil
the floor should not be manage by grease and oil spills and they should be wiped up from the surface.
Easy of clearing
surfaces that allow dirt to easily penetrate are harder to keep clean. The choice of floor should be easily to be cleaned.
Tendency of reducing noise
hard surfaces do not loser sound so they are nosier than soft surfaces.
Economic factor
The costs vary enormously for the huge range of finishes e.g. cement screed is more cheaper compared to carpet, wood block or floor files.
Controlling of warmth or coolness
Hard, smooth surfaces are cool to walk on because they conduct heat away.
But soft textured finishes like carpet give a room a warmer feel, which may be suitable for cooler dilates
Resistance to water spills.
The flooring in bathroom sand kitchens need to withstand water spills from washing or plumbing leaks.
Architectural beauty
The floor finish should provide good appearance eg. Floor tiles process good appearance compare to normal cement screed.
TYPES OF FLOOR FINISHES / FLOOR COVERINGS
Concrete floor covering
§ Concrete floor covering is provided over the sub- flooring of about 150mm thick
§ Normally depending on the requirements of thickness of floor finish, on top of concrete bed, the cement screed is provided acting as flooring finish.
Bricks
§ Are used as covering for comparatively cheap flooring for ordinary sheds, stores, temporary barracks
§ Good example of brocks which are used as flooring finish is engineering bricks.
§ Good example of bricks which are used as flooring finish is engineering bricks.
§ Mixing ratio for mortar depends on the durability required.
Terrazzo
§ The finished surface consists of about 10mm thick top layer of terrazzo mixture
Procedure for construction of terrazzo
§ Prepare a marble chips consists of 3 to 6mm size
§ Mix with a white or colored cement in the proportion of 1: 2 or 1:3
§ Provide patients by using dividing strips of ( metal 20 gauge) or glass or others materials.
§ Then laid terrazzo in layers over the prepared surface.
Mosaic
§ The sub base is similar to terrazzo
§ A thick bedding 6 cm of lime mortal is placed over the sub – base.
§ After mortar has hardened a 3mm thick layer of cement materials costing of slaked lime, powdered marble and pozzolana in the ration of 2:1:1 is load
§ After 4 hours tales of Mable slabs are kind in the specified Patten
§ The top surface is left for 24 hours and them given a polishing of pumice stone.
Tiles
§ Tiles are placed on lime concrete or lean cement concrete base.
§ A thin layer of 1:2 cement mortar is placed over the sub- base and tiles of required shape ,size and thickness placed over the sub – base
Wooden blocks
§ The flooring is normally constructed in one of the following ways Wood block covering
§ The sub-bade consists of lime concrete of (1:6:12 or 1:8:16)
§ 2 cm thick sand cushioning is provide
§ Then a blocks of wood of sizes varying from 20 to 30 in length, 8 to 10cm in width are kind and properly joined together.
Tiles
§ A thin layer of 1:2 cement mortar is placed over the sub- bade and tiles of required shape, size and thickness placed over the sub-base; there are different types of tiles one of them is
Vinyl asbestos tiles
§ These tiles are prepared in varying size from 225 to 300mm squire and thickness of 1,2,3 mm etc.
§ They are available in variety of colours
§ The composition of the tiles is asbestos fibers bonded with the 30% polyvinyl chloride (PVC)
§ Before applying to wooden, timber or concrete surfaces they are warmed and foxed to the surface with the help of bituminous adhesives.
§ The finished surface resists mild alkali and acid attacks and is not easily spoilt by grease.
Wooden blocks
§ The flooring is normally constructed in one of the following ways.
§ The sub- base consist of lime cemerete of (1:6:12 or 1:8;16)
§ 2cm thick sand cushioning is provided
§ Then a blocks of wood of sizes varying from 20 to 30 in length 8, to 10 cm in width are aid and properly joined together.
Glass
§ Structural glass is available in different patents and sizo of slay carried by closely spaced frames
§ This type of flooring is comparatively delicate and can take only light loads.
§ It is used in situations when light is required through the glass flooring to the floor below.
Vinyl asbestos tiles
§ These tiles are prepared in varying size from 225 to 300mm squire and thickness of 1,2,3 mm etc.
§ They are available in variety of colours
§ The composition of the tiles is asbestos fibers bonded with the 30% plying chloride (PNC)
§ -Before applying to wooden, timber or concrete surfaces they are warmed and foxed to the surface with the help of bituminous adhesives.
§ The finished surface resists mild alkali and acid attacks and is not easily spoilt by grease.
Carpet
§ These varies in term of colour materials used and Quality. And styles in term of decoration.
§ It cannot use for areas such as toilets or wet areas.
CLASSIFICATION OF FLOOR FINISH MATERIALS
INSITU FINISH MATERIALS
i. Cement screed and
ii. Terrazzo
NON – INSIT FINISH MATERIALS
i. Mosaic materials
ii. Dividing strips eg. Metal, wood
iii. Vinyl asbestos tiles eg.PVC tiles
iv. Blocks
v. Wooden blocks
vi. Capart
vii. Skirting and dividing strip
GENERAL PROCEDURES FOR PREPARATION OF SURFACE
§ Hacking the existing surface
§ Prepare the materials required
§ Clean the surface before applying the required types of finishes
TOOLS USED DURING APPLYING FINISHING WORKS
§ A bucket
§ A mixing board and shovel
§ Wood float and steel float
§ Screed board
§ Builders level
§ Grating machines e.g for terrazzo
GENERAL PROCEDURE FOR PREPARATION OF BASE
i. Hacking the existing structure eg. Hacking concrete.
ii. Clean the surface or apply special treatment of base required e.g. grouting applying bonding agent
iii. Prepare the materials required for carrying out type of finishes eg. Preparation of mortar, chipping etc.
iv. Prepare tools required eg. Buckets mixing board and shovel, wood floor or steal float, builders level, screen board etc.
NATURE OF THE BASE
§ concrete base
§ Brick work or Block work base
§ metal lathing
§ screened base
§ Timber base
SKIRTING
§ Also is the part of floor finish
§ It is the component which separate the ends of floor finish and plaster.
§ Normally is applied internally
§ It can be cement sand screed, timber, terrazzo, PVC tiles etc. and standard size 75- 100mm width and depth of 15- 20mm
§ Architectural beauty required the skirting to relate with the type of floor finishing applied.
DIVIDING STRIPS
§ These are used to provide patterns on the given surface.
§ It can be metal, wood or special rubber material
§ It is mostly used during applying terrazzo finish.
FLOORS STRUCTURES/ UPPER FLOORS
The function of any floor is to provide a level surface which is capable of supporting all the live and dead loads imposed.
In large- scale and multistorey buildings the floors are normally main structural elements closely related to the general structure of the buildings and as such they must be considered at the design stage.
CHOICE OF FLOOR
The main factors influencing the choice of floor type are:
i. Nature of the building;
The following is more suitable
§ A precast concrete floor
§ steel deck floor laid could be suitable
§ Insitu reinforced concrete frame
ii. Loading
§ Flat slab construction is economical for heavy uniformly distributed loading.
iii. Span
§ With increase in the span and ( in the load) these will normally be an increase in the thickness and weight of a solid floor slab.
iv. Degree of fire resistance required.
§ This is frequently a determining factor in the choice of floor.
v. Provision of services
§ The large number of services and extensive equipment required in many building determine the types of floor to use.
vi. Degree of sound insulation required.
§ Weight of structure is important in connection with insulation against air borne sound. The greater the weight the greater the insulation provided.
vii. Cost, speed of erection, adaptability.
§ Consideration of cost must enter in to the choice the floor type.
TYPES OF FLOORS
i) Reinforced concrete floors
These fall into the broad categories insitu cast and precast in each of which there list a wide variety of types.
Insitu cast floors
Because of being wet during construction required temporary support until the concrete is strong enough to bear its loads.
Types of floors under insitu cast floors.
§ Solid concrete floor slabs.
This type is commonly used when the slab is to act as a membrane supporting on columns without beams.
§ Flat slab floor.
This is the other form of insitu concrete floor without projecting beams.
The system is design for heavy evenly distributed superimposed loads and is economical for loading of 4.5 KN/M2
Suitable where there is no large openings or little solid partitions
§ Insitu hollow block floor.
This type of floor is lighter than the simple solid slab floor.
On this type the blocks are laid and to end in parallel rows about 75 to 100mm apart, according to the width required.
Reinforcement is laid in these spaces and concrete poured between and over t he blocks.
ii) Precast floors
The use of precast floors reduces or eliminates the use of shuttering.
In this type units are made in various width and depth vary according to span and load required in connection with the arrangement of beams and columns.
iii) Steel deck floors
The deck units are relatively light in weight , can be quickly hoisted in bundles and fixed in position.
iv) Open grating floors
This type of flooring is made up in steel , aluminum delay or glass reinforced plastic in panels of varying width and length required.
v) Spring floors.
Gymnasium and dance floors should be resilient.
This resilience is imparted by the use of a sub – floor of timber bearers With or without springs or rockers.
vi) Cavity floors or Raised floors
These are structural sub- floors raised above the normal floor slab to form cavity to accommodate example Cables etc.
Normally used in the areas such as laboratories and computer rooms etc
Cavity floors fallow into two types:-
§ Battened floors
These provide a shallow cavity for cable server usually us than 100mm in depth and may be formed by timber battens at 300mm centre supporting chipboard flooring in which there are removable strips over panels at intervals.
§ Pedestal floors
These provide a deep cavity over 1000mm so that a normal cable and environmental services can be accommodated. The flooring panels are supported on metal props or pedestals which are adjustable in height to permit leveling of the floor.
vi) Timber floors.
Also this is another type of floor which is normally used where the span and loading required is not heavy.
It is design in connection with supporting beams or projecting beams in order to reduce the dead and live loads.
PROVSION FOR SERVICES IN FLOORS
Services can be accommodated above the structural slab, within its natural thickness, below the slab or below its supporting beams.
Services which can be provided;
i. Electrical conduct
ii. Pipes for water, heartily, gas or drainage services may be laid either on top of the slab fixed to or suspended from or the soffit.
When laid on top of the slab the thickness of the finishing screed may be considerable especially if some pipe cross each other
