Walls Flashcards
Functions of walls
- Strength and stability
- Transfer of loads
- Fire safety
- Security
- Durability
- Heat insulation, sound insulation
- Aesthetics
What is an R – value?
R value is an indication of the insulation’s resistance to heat flow./ the thermal resistance
R – value equation?
R Value = Temperature difference /
Heat transfer per unit area
Thermal transmittance / u-value?
1) measures the amount
of energy(heat) lost through a square metre of that
material for every degree difference in temperature
between the inside and the outside.
2) u = 1/R
what is STC and NRC
1)ability of a material to block sound - stc
2) absorption of sound - nrc
characteristics of Sound
Absorbing Materials
- They are, usually, soft, light, fluffy, or porous, which enables them to
better absorb an echo. - They should contribute to the aesthetics of the room.
- It must improve the quality of a sound within the room.
- Must be cost effective.
Types of Walls
- Thatched Walls
- Rammed earth walls
- Soil cement walls
- Cement sand walls
- Brick walls with burnt bricks
Thatched Walls - Adv & Disadv
Advantages
Cost effective
Doesn’t absorb a lot of water
natural insulator
Lighter
Disadvantages
* mice are attracted
* Harder to insure
* Fire risk
* Walls have low strength
Rammed earth walls? adv and disadv
-wall made from pressed earth
Advantages
Temperature and noice control
* Strength and durability
* Low maintenance
* Fire proofing
Disadvantages :
* Very labor-intensive to build
* Relatively expensive
* Not a good insulator
Rules for bonding in brickwork
-Use bricks with uniform size
-The amount of lap should be minimum one-fourth of brick
-Avoid using brick bats
Types of bonding
- Stretcher bond
- English bond
- Header bond
- Single Flemish bond
- Double Flemish bond
Dampness?
presence of unwanted moisture in the structure of a building
Effect of Dampness
- Plasters become soft and deformed
- Warping and decaying of timber
- Corrosion of metals
- Electrical installations can be damaged
- Floor covering materials are deteriorate overtime
- Unhealthy for humans
How to Prevent Dampness
- By providing DPC ( Damp proof course )
- By surface treatment
- By integral water proofing method
- By special devices i.e. by providing chajjas & by providing
cavity walls
Reactive soils?
soil that expands dramatically when moist
and contract when dry
