Pros and Cons of Different Wood Shuttering Materials including Timber and PlywoodArticles > Pros and Cons of Different Wood Shuttering Materials including Timber and Plywood
Shuttering, which is also known as scaffolding, is a basic but complex process of forming construction mold by the shuttering/scaffolding material i.e. timber, plywood, steel, aluminum, plastic, magnesium and fabrics. All of these shuttering materials have their own advantages, but the wood is most frequently used shuttering material and the cost of wood/timber will be dependant on its quality. Moreover wooden formwork is, aesthetically pleasing architectural method. Painting the timber and using an oil or epoxy treatment can increase the life of the timber formwork, allowing you to use it many times.
Wood is available in two forms, one is timber and the other is plywood. Both of the types of wood have some advantages and disadvantages. First we will discuss the advantages and disadvantages of timber:
Advantages of Timber:
- It can be cut timely as per required size.
- It can be handled easily because of its light weight.
- It prevents the concrete structure to be damaged because of its thermal resistance.
- A damaged part of timber can be easily replaced.
- Dismantling of timber “form work” is quite easy.
Disadvantages of Timber:
Despite being so advantageous and popular all through the world, timber shuttering has still some demerits, which can not be avoided in the subject of civil engineering.
- A dry timber is a good absorbent of water. It absorbs the water of the concrete, and dries it soon. This process weakens the internal bonding of concrete material.
- In case, if the timber is soaked with water, the wet timber absorbs too much water which compresses the concrete structure and excess water shrinks down through joints, thus making grout leak and creating crakes within the concrete structure.
- As timber shuttering has short life, therefore, it can not be used for frequent times. After using timber shuttering for 5 to 10 time, It becomes useless.
Plywood is also a synthetic form of wood, but it is different from timber, because plywood is an artificially processed form of timber. It consists of number of veneer sheets of ply layers. Now-a-days the use of plywood is growing rapidly in formworks, because of it giving a smooth finish to the concrete structures, thus reducing the cost of finishing. Plywood boards are available in different sizes ranging from 7mm to 32 mm. Generally boards of 18 mm thickness are being used. A board with 1220 mm width, 2440 mm long and 18 mm thick board covers almost all types of form work.
Advantages of Plywood Boards in Formwork:
- Like timber, plywood boards can also be cut according to the required sizes.
- Unlike timber, plywood is more durable and can be used tens of times more than timber.
- Like timber plywood is also very light and can easily be handled.
- Unlike timber, it does not absorb the water of concrete.
- Plywood gives a smooth fish to the concrete, which, later on, reduces the cost of finish.
- Plywood can also be used in curved formworks.
- Extra-ordinary large sizes of plywood are available which makes the construction work easy and speedy.
- It can be reused frequently as compared to the timber.
Disadvantages of Plywood in Formwork:
- While comparing with timber, plywood is much costly.
- Some times, thin plywood sheets can not sustain the burden of concrete and the concrete mass tends to bend in many cases.
- Plywood sheets are more elastic if compared to timber. Elasticity of plywood, sometimes, de-shapes the mold.
Different Materials of Wooden Shuttering:
There are dozens of different types of wooden shuttering material with different names in different areas of the world. However, the common most shuttering material, which are known all over the world are:
- Scaffold Boards
Wooden Scaffold Boards are made up of either timber or plywood. They are used as temporary walls to the concrete structure. It prevents the concrete from flowing down. When concrete dries after few days, these boards are dismantled.
- Wooden Logs:
Wooden logs are long round pole like wooden logs which are used to support the Shuttering boards. Shuttering boards are installed upon the wooden logs to design a mold. The length of these logs ranges from few feet to 18 feet.
- Support Boards:
Wooden Support Boards are used under the concrete structure to make the structure sustain itself. Generally the sport boards are used under the concrete material of roofs. These are wider but shorter in length than the common scaffolding boards. These are also called wooden panels.
- Petty Scaffolding
Petty Scaffoldings are generally made up of bamboo trunks, which are longer than a normal wooden log. Petty Scaffolds are tied with one another by means of ropes in order to construct a skeleton. Then the wooden boards are placed on the skeleton to. When concrete structures are dried and hardened, the petty scaffolding along with the other shuttering items is dismantled.
- Nails in Wooden Shuttering:
Nails are made up of iron and steel. The purpose of nail in shuttering is to join the shuttering boards with wooden logs and other types of scaffolding boards.
After the concrete dries and hardens the nails are unplugged and the whole shuttering is dismantled.
- Shuttering Oil:
The black, used, viscous and lubricant automobile engine oil is poured on the shuttering material in order to avoid sticking with concrete structures. Use of greasy oil helps easy dismantling of shuttering material.
Cost of Wooden Shuttering:
We recommend Wooden Shuttering and scaffolding, because Timber as well as Plywood formworks can be carried out at a lower starting cost when compared to steel because of its availability and cheaper production costs. The cost of timber will be dependant on the quality of the wood. Moreover wooden formwork is, aesthetically pleasing architectural method. Painting the timber and using an oil or epoxy treatment can increase the life of the timber formwork, allowing you to use it many times.
Wood is a natural resource and natural resources always cost lower than the artificially synthesized products. In many cases timber may cost higher in areas where the forest are rare. However, the fast and advanced means of transportation made the supply of timber possible every where in USA and the rest of the world.
- Wood Shuttering for Concrete
- Wood Shuttering Boards
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- Formwork and its types on the basis type of construction
- Solved Example: Design of 2x10 Timber Floor Joist with Southern Pine