Logbook Week 7: Knowledge Map:

E-Learning Content: Prevention of moisture and heat: Prevention of Moisture: For water to penetrate into a building, three conditions must occur: • Opening • Water present in the building • Force to move through building Therefore in order to remove water from the building, it is sufficient to remove one condition of them, but removing more conditions is more secure in waterproofing. Three ways to prevent moisture in the building: • Removing opening

1. Sealant (silicone) 2. Gasket (made from artificial

rubbers) • Keep away water in the opening

1. Using sloping roof with great

pitch. 2. Using tile roofs where tiles are

overlapped with each other.

• Forces to be considered as: 1. Gravity 2. Surface tension 3. Momentum 4. Air pressure differential The following sketch shows how tiles work under raining conditions. Rainwater would flow along the surface of tiles, the rate of water flow is proportional to the pitch of the roofs.

Maintenance of Heat: Heat: ü Heat is conducted through the

building. ü In the building envelop, building

elements are subjected to radiate heat.

ü Thermal mass is to regulate heat through building envelope.

Different ways to maintain appropriate room temperature: • Thermal insulation • Thermal breaks

• Double glazing • Reflective surface • Shading system Large area of exposed thermal mass absorb and store heat over a period of time, the materials include the following: ü Masonry ü Concrete ü Water bodies Control air leakage: • Opening • Air present in the building • Force to move the air into the

building Rubbers: Rubbers can be seen as both natural materials from rubber tree and artificial materials, two types of rubbers are used in the current industry; they are called natural rubbers and synthetic rubbers.

Properties of rubber: • Hardness (hard rubber resist

abrasion, while soft rubber provide better seals.)

• Fragility (Low; it will not shatter and break.)

• Ductility (High when heated and varies under cold state.)

• Flexibility (High flexibility) • Porosity (can be considered as a

waterproof materials) • Density (approx. 1,5 times dense

than water.) • Conductivity (poor conductors of

heat and electricity.) • Durability (very durable.) • Reusability (High) • Sustainability (embodied energy

varies greatly between natural rubber (very low) and synthetic rubbers (medium); it is renewable if they are correctly managed.

• Cost (generally cost effective)

Natural rubbers are used for: • Seals • Gaskets • Flooring • Insulation • Housing and piping

Synthetic rubbers are used for: • EPOM (gaskets and control joints) • Neoprene (control joints) • Silicone (be used to seal)

Damage: The damage of rubber is mostly weather related damage, so avoid to be directly exposed under strong sunlight. Plastics: Sourcing of plastics: The plastics are made from element such as carbon, silicon, hydrogen, nitrogen, oxygen and chloride combined by chemical reaction into

monomers. After that, the monomers combine with each other to form polymers. Types and uses: 1. Thermoplastics

• Polyethylene • Polymethyl methacrylate • Polyvinyl chloride (PVC) • Polycarbonate

2. Thermosetting plastics---can only

be shaped once • Melamide---finishing surfaces • Polystyrene---used in

insulation panels

3. Elastomers (synthetic rubbers)

• EPDM • Neoprene • Silicone

Properties: • Hardness (Medium-low, depending

on types of plastics) • Fragility (low-medium, generally

not shatter or break; high temperature can degrade some plastics quite quickly)

• Ductility (high when heated; varied under cold state)

• Flexibility (high flexibility and plasticity)

• Porosity (many places are waterproof)

• Density (low, 0.65 times than water)

• Conductivity (poor conductors of heat and electricity)

• Durability (can very durable) • Reusability (high for

thermoplastics, but very limited for thermosetting plastics)

• Sustainability (embodied energy varies greatly between recycled and not recycled)

• Cost (generally cost effective) Considerations: Weather related damage when exposed to weather especially sunlight and it need to be checked and maintained. Protection: Avoid or minimize sun exposure when possible. Some plastics have very high

expansion/contraction coefficients. Paint: Component: Binder---the film-forming component of the paint Diluent---dissolves the paint and adjusts its viscosity Pigment---gives the paint its color and opacity

Types & uses: Oil based: • Used prior to plastic paints (water

based)

• Very good high gloss finishes can be achieved

• Not water soluble (brushes to be cleaned with turpentine)

Water based: • Most common today • Durable and flexible • Tools and brushes can be cleaned

with water. Properties: • Color consistency (the color of the

paint should resist fading) • Durability (paints need to resist

chipping, cracking and peeling) • Gloss • Flexibility (water based paint is

more flexible than oil based paint.)

Glossary: a) Downpipe:

A pipe to carry rainwater from a roof to a drain or to ground level

b) Flashing: Flashing refers to thin pieces of imperious material installed to prevent the passage of water into a structure from a joint or as part of a weather resistant barrier system.

c) Insulation: It is a material to resist heat or moisture coming inside the building

d) Sealant Sealant is a viscous material that does not allow water or moisture to penetrate the substrate by means of capillary action

e) Parapet: Parapet is a barrier which is an extension of the wall at the edge of a roof, terrace, balcony, walkway or other structure.

f) Gutter: It refers to a narrow trough or duct which collets rainwater from the roof of a building and diverts it away from the structure.

g) Vapor barrier: It is any material used for damp proofing, typically a plastic or foil sheet that resists diffusion of moisture though wall, ceiling or other members.

Referencing list: 1) Concrete Deck or Open Roof，

viewed by 29.4.2014  http://www.monier.in/technical-guidance/preliminary-questions/concrete-deck-or-open-roofs.html

2) Bridgestone Commits to Natural Rubber Development, 25.2.2011, viewed by 29.4.2014  http://www.jaxquickfit.com.au/blog/2011/02/bridgestone-commits-to-natural-rubber-development/

3) India’s Synthetic Rubber, viewed by 29.4.2014  http://automotivehorizon.sulekha.com/india-s-synthetic-rubber-consumption-up-18-44-percent_newsitem_2376

4) THERMOPLASTIC TUBING EXTRUSION SERVICES, viewed by 29.4.2014  http://www.akronpolymer.com/thermoplastic-tubing-extrusion-services.html

5) What is thermoplastics, wiseGEEK, viewed by 29.4.2014  http://www.wisegeek.com/what-is-thermoplastic.htm

6) Organic Pigment Suppliers- Color Dispersions, viewed by 29.4.2014  http://www.aarbor.com