WOOD SPECIAL TYPES AND ALTERNATIVES

WOOD

A natural organic material that has been used for many centuries for the construction of buildings, bridges and a variety of other structures. Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants.

WOOD

WOOD ADVANTAGES OF WOOD

DISADVANTAGES overpeck park bridge,NJ

CLASSIFICATION OF WOOD

PROPERTIES OF SOFTWOOD:

Contract with heat & moisture

Have lower density than hardwoods (good for acoustic & thermal insulation

Good for interior finishes & for furniture

Solid but soft

Flexible & strong

Not water resistant

Cost : low

PROPERTIES OF HARDWOOD:

Contract with heat & moisture

Stronger, denser, & homogenous than hardwoods (good for framing system)

Good for interior finishes & for furniture

Resist fire better than softwood

Nearly impervious to water (some varieties)

Cost : high

COMPARATIVE ANALYSIS

WOOD STRUCTURE

Bark

Bast

Sapwood

Heartwood

Pith

WOOD & TIMBER

WOOD is the hard, fibrous material that makes up the tree under the bark TIMBER is a wood which retains its natural physical structure and chemical composition and is suitable for various construction works

STORAGE Timber stored in water after felling reduces the

risks of molds & insect damage

SPLITTING/SAWING

Should take place while the

trees is still very damp

DRYING 70-90% of the original moisture must be

removed from the timber before this could be

used for construction..a reason why routine drying is important

CHARACTERISTIC OF GOOD TIMBER

METHODS OF PRESERVATION

External application of preservative coating

Internal timber is subjected to pressure & injected with chemical such as zinc

chloride solution/salt

Structural

Members &

Framing

APPLICATION IN CONSTRUCTION Wood has been an important construction material since humans began building shelters, houses and boats. Wood to be used for construction work is commonly known as timber (lumber in North America). In buildings made of other materials, wood will still be found as a supporting material, especially in roof construction, in interior doors and their frames, and as exterior cladding.

New domestic housing in many parts of the world today is commonly made from timber-framed construction. Engineered wood products are becoming a bigger part of the construction industry. They may be used in both residential and commercial buildings as structural and aesthetic materials.

Flooring

APPLICATION IN CONSTRUCTION

Outdoor Deck

Ceiling Panel & Joists

Exposed Structural

Member

FLOORING Wood is a common choice as a flooring material due to : -its environmental profile, durability, and restorability.

Railing & Balustrade

Paneling Furniture Cabinets

Doors Windows

Wood products are used in a variety of applications, from home construction to commercial buildings to industrial products. The products can be used for joists and beams that replace steel in many building projects.

Very large self-supporting wooden roof. Hanover, Germany.

75 Unit Apartment building, made largely of wood, in Mission, British Columbia.

HARDWOOD Hardwoods come from deciduous or broad-leafed trees. They are generally

slow growing which tends to make them harder and more expensive. Hardwoods have a more complex structure than softwoods. The dominant feature separating "hardwoods" from softwoods is the presence of pores.

Characteristics features :-

Hardwoods usually have broad leaves. It can distinguished by the structure of the wood grain. They grow slower than softwoods so they are more expensive. Hardwoods include Ash, Rosewood, Oak, Teak and Mahogany.

Applications of hardwood

Flooring Seating Building material(auditorium)

Teak

Mahogany

Rosewood

Oak

1.Mahogany

It is the most versatile and durable of all the hardwoods. It is a dark, red brown coloured tropical wood which is resistant to insects and rot, has an

attractive grain and polishes to a beautiful high sheen.

This wood has an interlocking grain which makes it resistant to water damage and seepage.

It has a fine to medium texture, with grain that varies from straight to wavy or curly. Architectural application

Non-Architectural application

Advantages

Its easy to work because of its grains which is neither to hard nor to soft. Its a versatile material that can be used anywhere and with everything.

Disadvantages

Its very expensive. Last long only if proper care is taken. It have to be kept away from the sun and rain as heat and water can

damage the wood and the finish.

It tends to darken with age.

2. Teak

It is one of the hardest, strongest and most durable of all natural woods. Teak is a close grained hardwood. This makes it possible to cut joints very accurately

and makes it suitable for carving as the close grain means it can be carved to include

great detail.

It is resistant to rotting and to the effects of hot sun, rain, frost or snow, making it most suitable for outside.

High in natural oil and rubber content.

Architectural application

Wooden house Ceiling Exterior flooring

Advantages

It have very long life up to 100 years. It can withstand very harsh climatic conditions. It is low maintenance.

Disadvantages

Its oil makes it difficult to work with glue or other sticking material. It is easy to cut but because of its brittle nature it damages the tools

easily.

Bamboo

It is one of the fastest growing plant on the earth. The strongest part of a bamboo stalk is its node where branching occur. Dry bamboo is stronger than wet bamboo. It has high tensile strength. It can be used a complete building material.

Architectural application

Non Architectural application

Advantages

It is lightweight. It is cost effective. It has high flexibility. It is earthquake resistance. It has high strength.

Disadvantages

For construction can be used upto 3 stories.

SOFTWOOD

Softwood is lighter and more flexible than the hardwood but is more or less similar to it in strength.

SOFTWOOD

o It is derived from evergreen trees and can be used for the construction of wooden floors, walls, desks, furniture, door and wooden panels.

o However, softwood might not be an ideal choice for walls and ceilings in urban houses.

o Softwood is mainly used in the making of doors, door panels, window frames and furniture. Some types of softwood can also be used as a flooring material.

o Softwood properties:

Softwoods come from coniferous trees. Softwoods are special because they dont lose their needles. Softwoods have needles instead of leaves. Softwoods grow faster than hardwoods so are cheaper. Often used as building material. Trees grow tall and straight which makes it easier for the manufacturer to cut long straight planks of wood.

TYPES OF SOFTWOOD

1. CEDAR 2. HEMLOCK 3. PINE 4. FIR

Cedar

Cedar has the quality of density and lightweight to make it an excellent choice in construction. Cedar is resistant to decay and the aromatic oil wards off insects and makes this an excellent choice for closets and other wall coverings.

Uses of cedar

In addition to the use of cedars for beauty and scent in landscapes, this site gives a number of other uses for which cedar is an ideal choice.

o People buy cedar trees for landscaping or as ornamental trees. o Most important fact about Cedar wood is that it is resistant to decay so this is used for closets and

wall covering. o Ceilings, beams, windows, doors, and posts can also be made from Cedar wood. It is a proven ideal

building construction material. o Cedar wood is also used for making outdoor and indoor furniture and fixtures as they are durable,

light weight and very easy to work on.

If you have the place and is looking for excellent business opportunity try to plant some Cedar Trees and then when they are grown put the Cedar Trees for sale. It is in huge demand and is a good investment as well.

Hemlock

The Eastern hemlock is not a top choice in the use of construction as the wood is full of knots. A popular ornamental tree in landscaping, the wood from the hemlock is used as pulpwood or in the construction of railroad ties.

Hemlock is used for the making of doors and planks. It is not very resistant to rot hence; it is not used in the making of wooden floors.

The softwood that toughens up with age

Although it might not be as strong as concrete or brick but it is strong and durable enough to be used as a building material.

Uses in woodworking

o The construction industry now frames, sheathes, and floors with hemlock. Mills turn the wood into windows, frame-and-panel doors, moldings, and paneling.

o Due to its strength and wear-resistance, hemlock also becomes reliable ladders and stair components.

Cost and availability

Vast logging operations on the Pacific Northwest coast keep hemlock widely available in the West and Midwest. On the East Coast, even availability of local hemlock is spotty.

Pine

White pine wood is a popular choice for many construction projects from crafts to home construction. Pine wood is inexpensive, readily available, ranges from clear to knotty, and is a favorite choice for cabinetry, woodworking projects of all types and furniture.

Eastern white pine

Uses:

o Eastern white is used extensively in all areas of woodworking, cabinets, scroll saw & craft work, folk art and even wood turning for table legs.

o We make it into lumber, flooring and wall paneling.

Weight: approximately 26 lbs./cu.ft.

Machining:

It is extremely easy to cut with both hand and machine tools. Sanding is easy, but you must work your way down the grit ladder. It cuts easily with a scroll saw, but remember that it is not very strong, so don't leave little strips going across the grain or they'll break.

Fir

1. Coastal Douglas-fir 2. Interior Douglas-fir

Common Uses

Douglas-fir is primarily used for building and construction purposes due to its strength advantages and availability of large dimensions from old-growth trees. It is one of the finest timbers for heavy structural purposes, including laminated arches and roof trusses. Structurally, it is used in the form of lumber, timbers, pilings and plywood.

The wood is also used to produce a wide variety of products including general millwork, flooring, furniture, cabinets, veneer, vats, ship and boat construction, transmission poles, and marine pilings.

Fir, especial Douglas fir accounts for one fourth of all lumber produced and used in North America. Douglas fir is used in lumber, plywood, house logs and posts, as well as firewood and fencing. Douglas fir trees are also a popular choice for Christmas trees.

Fire resistance door

ALTERNATIVES

Hemp is a fast-growing and sustainable crop that generates more construction-grade fiber per acre than most trees and other crops. It can be used in place of lumber and a wide range of other materials. For example, Washington State University researchers found hemp-based medium density fibreboard to be twice as strong as wood

Hempcrete is a mixture of hemp hurds (shives) and lime used as a material for construction and insulation. Hempcrete is easier to work with than traditional lime mixes and acts as an insulator and moisture regulator. It lacks the brittleness of concrete and consequently does not need expansion joints.

When hemp hurds are mixed with a combination of lime products, they can produce a light weight

insulating plaster, which can be cast around a timber frame or sprayed against a wooden or even stone

form. Interior walls can be left exposed or finished with a natural paint. partly because of its high

insulation properties but also because it works in old stone buildings

Shuttering under construction for hempcrete wall

Joining two shuttering boards together for the next lift

Mixing hempcrete in a drum mixer .

Tipping hempcrete into the shuttering.

Using a nail float to soften a hempcrete corner.

A hempcrete wall with shuttering partially removed

Plastering effect on hempcrete wall

Hemp and lime for mixing

It is rich in silicon oxide particle has a very favourable behaviour when it comes to masonry.

It has great absorption capacity brings important technical advantages. The formwork technique allows a great amount of architectural creativity as

well as the flexibility required for the creation of curves.

It is non flammable in nature Good thermal insulation properties offering some thermal mass Lightweight material with simple construction details and processes Light weight reduces load on foundations, so less need for materials with

high embodied energy (eg concrete)

High level of understanding of specific product required by designers and contractors

Onsite construction more suited to warmer months (drying times reduced), although in winters it requires special care.

Requires time and shelter during drying on site before finishes can be applied.

Use limited to above damp-proof course or equivalent level

ADVANTAGES

LIMITATIONS

Wood plastic composite (WPC)

Wood plastic composite is a hybrid material composed of natural wood and plastic fiber. Saw

dust from fiber fillers like pulp, peanut hulls, and bamboo are mixed with new or

waste plastic powder, from materials such as polyethylene, polyvinyl chloride, polypropylene,

and acrylonitrile butadiene styrene.

Combination of Wood-Plastic

Thermoplastic- HDPE, LDPE, PP, PVC

Wood- Pine, Oak, Maple

Lubricants- Pigments, Coupling agents, other additives

FIXING

By screwing two sections. By interlocking

Tongue and grove joint

1) Dimensional stability, longevity, natural feel 2) Stable over a wide temperature range, whether resistant 3) High impact resistant 4) Environmental-friendly, recycle 5) Board range of finishes and appearance 6) Contains no toxic chemicals or preservatives 7) Resistance to rot and crack 8) Moisture resistant, low flame spread

ADVANTAGES

1) Installation Requires skilled labours. 2) Only sections are available each and every section to be joined manually. 3) Costly as compared to wood products.

DISADVANTAGES

These are hollow-core blocks are made from mineralized wood shavings and portland cement, stacked into walls and then finished with reinforcing steel and concrete. The

company says the material is noncombustible, sound absorptive, and dimensionally

stableand is made of 78% recycled content. It's also 100% recyclable.

DURISOL

Durisol Wall Forms are lightweight and straightforward to use. construction is fast and efficient. This results in lower labour costs and shorter

construction time. The Durisol material can be easily cut, nailed and screwed with simple carpenter

tools. This provides the builder with the flexibility to cut and fit shapes to suit site-specific situations.

Wood bucks and bracing can be directly attached to the Durisol Wall Forms using nails and screws.

CONSTRUCTION ADVANTAGES

PERFORMANCE ADVANTAGES

INSULATION SOUND PROTECTION THERMAL MASS EFFECT FIRE RESISTANCE MOISTURE PROTECTION

THE OTHER ALTERNATIVE TO WOODS ARE BAMBOO SOY CORK CARDBOARDS NUTSHELLS STRAW etc

REFERENCES WEBSITES

http://www.networx.com http://www.hemp.org/ http://balconyfloor.com/ http://www.coldhamandhartman.com/