Roofs are the topmost elements of building systems. The building material used in these elements is generally wood. In this article, we will try to examine the reasons, advantages and disadvantages of wood material in roof.
What is a roof?
They are the elements created to protect the building from atmospheric effects. In these types of building elements, wooden material is generally chosen while creating the carrier system and coating elements.
The use of wood material on roofs dates back to prehistoric times. The main reasons for choosing the material are:
- It is resistant to corrosion
- High strength
- Being an economical material
- Easy to shape
Today roofs; It is divided into two as roofs with (cold) and not (hot) spaces.
Cold roofs are roof systems used before the Industrial Revolution and produced with a slope. These roofs do not allow the use of the attic as the insulation material is applied to the ceiling part of the building rather than the sloping part.
Warm roofs do not cause a problem in the use of the attic, as the thermal insulation material is made on the roof system.
As we can guess from these definitions, hot roofs are generally used in roof systems.
Comparison of Wood Material with Other Materials
Different materials can be used in the production of the roof system. Let’s examine the various comparisons of wood materials with other building materials in the research entitled “Alternative Roofing Materials in Housing Construction” published in 1994, from the table below.
Performance Criteria Required for Roofs
Atmospheric effects such as snow, rain, wind, water vapor, sunlight shorten the life of wood.
- The roof must be strong enough to carry the moving loads coming to it and must be able to transmit these loads to the carrier system.
- Since water causes deterioration and decay in wood, structural and chemical measures can be taken against this situation. As a structural measure, the roof slope can be increased in order to drain the water early. As a chemical measure, wood material can be impregnated and its resistance against degradation can be increased.
- Temperature and sun rays can cause expansion and contraction of the elements. Such situations may cause different deformations on the roof. As a precaution, insulation materials can be preferred between the rafters or on the floor.
Layers on Roofs
- There is also the possibility of the roofs being blown due to the wind. For this reason, the dimensioning of the roof should be done safely according to static and dynamic loads.
- In addition to the weight of the building itself, the weight of the roof also comes as an extra load on the structure. For this reason, there is a need for a member that will reduce the weight of the roof but with high strength, and this appears as wood.
Wooden Roof Elements
Coating: It is the element that ensures the smooth creation of the roof surface. Covering board is used underneath to set the coating.
Rafter: It is a roof element on which the under-coating board rests and sits on purlins with an axis interval of approximately 50 cm.
Aşık: They are the elements on which the rafters sit. The purlins try to bend the loads of the rafters and are transferred to the pillars in the fixed roofs.
Pillar: Elements that transmit the loads received from the purlins to the structure. Pillars on suspended roofs are called “bos”. Post sizes are usually chosen as 10/10 or 12/12.
Tree Types Used for Roofs
Before the Industrial Revolution, solid materials were generally used as materials, but later composite materials were used.
Solid Material: These are materials that are dried or used directly without drying.
Composite Material: Materials formed by the combination of at least two different materials.
While materials such as oak, chestnut and poplar were used as massive materials, today trees such as pine, spruce and fir are used more.
OSB (Oriented Strand Board) is generally used as covering material. This material is divided into classes according to moisture and humidity.
Solid materials are generally preferred for elements such as purlins, rafters and roof trusses.
The choice of material to be used in roofs, which are the carrier elements of building systems, depends on many factors. The mechanical properties of the material, its resistance to environmental factors, its economy and sustainability should be the main issues to be considered in this selection.
The advantages and disadvantages of a wooden roof frame
Each construction material has its own advantages. Wood material has two main functions why this material is desired by most people to be used as a roof truss . First , of course it was chosen because of its strength which is resistant to rust and corrosivity, which often occurs in the third high humidity.
Second , it was chosen because the wood has a unique texture, so that in addition to its strength, it can also be exposed to give the impression of a natural or traditional building. For more details, let’s see the explanation of the advantages and disadvantages of the following wooden frame.
The advantages of a wooden roof frame
Easy to do work
The first advantage of using a wooden roof frame is that it is easy to work on. This makes it easy for you to find experts in installing roof trusses from wood. Almost in every area there must be a lot of craftsmen who can work on the roof truss made of wood.
Flexible in Manufacturing
The next advantage of using a wooden roof truss is that it is flexible. The flexible nature of wood will certainly make it easier for builders to make a frame according to the wishes of the home owner.
Also Read: How to Make Roof Tiles
All these things, of course, will not be done easily if you choose a roof frame made of other solid materials such as aluminum, concrete or iron.
Bring out a natural feel
Giving wooden accents to buildings can certainly create a natural feel to the house. Likewise in the case of the use of wooden roof trusses.
The atmosphere of the house will be more beautiful and cool if you use a roof frame made of wood. This has made market demand for wood-based roof trusses never decreased.
Lack of a wooden roof frame
Easily Eaten by Termites
Termites are natural enemies of wood materials, regardless of their type. To avoid termite infestation, you must choose types of wood that are old and meet a certain level of hardness. If your area is known as an environment that has high humidity and a lot of termites, you must be careful in choosing the material of each wood for the roof frame.
The main disadvantage of wood material is flammability. As strong as wood, if you have to meet fire, then that’s it. If a fire occurs in a building that uses a roof frame, it is certain that it is difficult to extinguish and spreads quickly, because of the nature of the wood which is flammable.
Can expand and shrink
Wood is a material that has natural properties to expand and shrink. Especially wood that is not really old and dry, this type of wood can still expand or shrink due to certain conditions. This can affect the density of the wood joints. For that, you must choose wood wisely for the roof truss.
Choose a wood or light steel roof frame
- First. If you want a frame construction that has a long service life and is non-flammable, choose a mild steel frame.
- Second, if you want a frame construction that can be exposed to show the natural feel of the interior of the house, choose a wooden frame.
- Third, if you want a material that any builder can turn into frame construction, choose a wooden frame. Because not all builders are familiar with mild steel.
Types of wood for roof frames
There are many types of wood that can be used as a material for roof truss construction. We will review one by one the selected wood types that can be used as a basic material for making roof trusses.
If you demand strength and endurance against termites, of course the Javanese teak wood and Kalimantan camphor wood can still be said to be in the lead. But unfortunately, in the field the existence of these two logs for roof trusses is increasingly rare, of course the main factor is because the price is too expensive.
For that we will discuss several types of wood for roof trusses, which have the strength and durability approaching the two types of superior wood.
This type of wood is usually used as the main material for building construction. Meranti wood generally has straight trunks so it is very suitable to be used as a roofing material. Meranti wood is a very durable type of wood for the roof frame but has an uneven texture and is also a little rough on the surface.
The name of this wood may be a little foreign to people who are unfamiliar with this type of wood. However, it turns out that this wood is very suitable for being a roofing material. This is because Bangkirai wood is a strong type of wood. Apart from being used as a roofing material, usually this type of wood is also often used as a basic material for shipbuilding.
Mersawa wood is a very durable type of wood. Therefore, this wood is often used as the basic material for making roof trusses. In addition to roof trusses, this wood can also be used as material for shipbuilding. In terms of texture, this wood has a texture that is not much different from bangkirai or meranti wood.
The next type of wood is lime wood. This type of wood is generally used as a material for frames and also for roof frames. Classified as a type of wood that is strong, lime wood is also often used as a basic material for shipbuilding. The characteristic of lime wood is that it has an even texture with a slightly rough wood surface.
Coconut wood, which has the Latin name Cocos Nucifera, is a newcomer who is starting to be in great demand for frame construction needs. The rarer the super quality forest wood, the higher the price of this type of forest wood. As a substitute for coconut wood with super quality, it can be a new option that is also equipped with no less capable strength to be used as a roof frame.
Mahogany tree is a tree that has the characteristics of small leaves. This type of wood is quite easy to find in Indonesia. In general, mahogany trees can be found easily on the side of the road. Besides being able to be used as a material for making house roof frames, mahogany is also often used for other basic building materials.
Indeed, wood frames are still in great demand and use by people who still believe that the combination of wooden frame construction with clay tiles is the perfect combination of roof cover types for residential homes. Now, what is often used is the type of Meranti roof truss and Coconut wood.
The wooden roof frame is one solution for the frame of your home. This is because wood is a material that is classified as strong and also durable.