ENV 500Housing & Residential environment

Lesson 5

Design and Constructional Requirement•Foundations•Walls•Floors•Roof•Materials toxicity

House Components

•Method of construction, type of design, and choice of materials depends on:1. Building requirement2. Supplies of building materials3. Manufacturing plant4. Availability of trained building

construction workers5. Climate conditions6. Site conditions7. Finance8. Consumer interest

1. Facilitation of household tasks• Meet general and individual physical and

mental health requirements as well as comfort and aesthetic considerations

• E.g space – sufficient for people and storage space.

• Easily clean floor and wall – reduce time for clean

• Usage of household appliances – vacuum cleaner, washing machines – reduce mental stress and fatigue.

Easy maintenance and repair building materials•Healthy house design for floor, walls,

ceilings, work surface and appliances should be:▫Constructed smooth▫Impervious material for easy cleaning▫Easily assessable parts for cleaning

purpose▫Anti dust-trap▫Suitable hygienic facilities for personal

belonging

•Building structure should be:▫Strong▫In good repair▫Not likely to collapse▫Loose roof, slates should be properly

secured▫Structural timbers rotted and damage

should be replace with new impregnated timbers

▫Replace ceiling that bulged

Foundations

•Design must be taken into account the possible ground movementi. topsoil – loose soil, soft and not suitable

for foundationii. Fine-grained soil – e.g clay, may hold

pressure and better result for foundation.

•Foundation should be laid at suitable depth to prevent shrinking and expending effect of clay soil.▫May laid 1m to 4m in depth from surface.

•Rock produce better effect as this element does not compact under the weight of the building.

•Tipped soil,ex-refuse and ex-waste site is NOT suitable for housing due to possibility of contamination and exposure.

•Building foundation should able to transmit the building load uniform to the ground – avoid damage service to pipes and drain

•Type of foundation:i. Raft foundationii. Strip foundationiii. Pad foundationiv. Pile foundation

Raft Foundation

• are used to spread the load from a structure over a large area, normally the entire area of the structure

• used when column loads or other structural loads are close together and individual pad foundations would interact

Strip Foundation• used to support a line of

loads• either due to a load-

bearing wall, or if a line of columns need supporting where column positions are so close that individual pad foundations would be inappropriate.

Pad Foundation• used to support an

individual point load such as that due to a structural column

• may be circular, square or rectangular

• consist of a block or slab of uniform thickness, but they may be stepped or hunched if they are required to spread the load from a heavy column

• usually shallow

Pile Foundation

• Structures place on top of the piles.Piles + Pile Cap = Pile foundationFunction : Distributes load to the individual piles.Pile Cap will connect the pile together and distributes the superstructure loads to the layer beneath.

• The main components of the foundation are the pile cap and the piles

• The main types of materials used for piles are Wood, steel and concrete

WALLS

• Protecting building and forming compartment and rooms internally.

• Internally walls should easily cleaned and durable for indoor activity

Good walls should be able to:-▫Provide stability▫Strength▫Durability▫Fire resistance▫Exclude rain/humidity▫Thermal insulation▫Sound barrier/resistance

Common materials for walls

Clay bricks• Provide stability, durable

and good resistance to fire• Good thermal and sound

insulation• Cheap

Clay blocks• Lightweight• Made from clays• Do not suffer moisture

movement• Good fire resistance• Mainly used for internal

non bearing loaddue to poor thermal insulation properties

Concrete Blocks• Used for both load bearing

and non and bearing walls• Good insulation properties• Cheap• suffer to moist movement-

cracking prone on plaster layer

Concrete walls• Extremely strong• Good fire protection and

weathering• Drab/dull appearance• Normally used for high

storey units.

Asbestos• Extremely durable and

good thermal insulation/fire resistance

• Brittle and lack of structural strength

• Commonly associated with health problem

Corrugated Iron• Not normally suitable for

walls due to poor thermal insulation

• Rusting and corrosion problem

Timber• Support sufficient

strength for small building and houses

• Good thermal insulation• Need protection form

insert attack, decay and weathering effect

Floor

Functional requirement for floor:i. Stabilityii. Strengthiii. Moisture resistanceiv. Durabilityv. Fire resistancevi. Thermal propertiesvii. Sound resistanceviii.Sound adsorption

Floor stability

• Adequate vertical support• Adequate stiffness against

deflection when under load.

Floor Strength

• Capable of adequately support people, furniture, and household equipment.

• Able to support dead load of floor structure.

Floor durability

• Solid base or solidly supported suspended floor should last for a life of the property.

Moisture Penetration

• Damp floor, cold and uncomfortable foot.

• Aggravate respiratory illness of occupant

• May caused wood/timber rot.

Fire Resistance

•Requirement depend on the height of the building.

•Normally concrete flooring is used for higher level.

Sound Transmission & Sound Adsorption

•Concrete are better than timber material•Impact sound can be deadened by

carpeting and other flooring materials •floor finish need to be smooth,

impervious, easy to kept clean and non-slip.

Roof

•Functional requirement of roof are:i. Stabilityii. Strengthiii. Exclusion of rain and windiv. Durabilityv. Fire resistancevi. Thermal properties

•Should be able to support dead load of roof structure, covering, pressure, and wind (snow if occurs).

•Flat roof stability depends on support from walls and beams

•Pitched roof depends on the depth of triangular framing at mid-span.

•Strength for both depends on the materials selection, method and construction.

Flat roof Pitch roof

Common type of roof materials:

i.Bitumen ii.Fiber based materialsiii.Asphaltiv.Sheet metal (copper, Zinc, lead,

aluminum)v.Claysvi.Stone slate

Roof should be able to:i. Durable to protect water from decaying

structureii. Resistance to damage by fireiii. Insulation against transfer of heativ. Exclude animals intruders

3. Choice of building materials, furnishing, and consumer goods.▫ numbers of toxic chemicals used in

building materials and furniture.▫Contribute to certain health problem e.g

indoor air pollution, ingestion (lead), polymers.

Asbestos & Lead,

•Read notes•Please find relevant info on usage of

asbestos inside house•Health effect