The seasoning yard should be paved and well drained, and the timber supported on cast iron bearers, and piled so as to admit of the free circluation of air over all the surfaces of the pieces. Natural seasoning when timber is felled, the sooner it is removed from the forest the better. Air seasoning the easiest way, but not the most effective method of seasoning timber, is to stack it outside. Timber stacked on trolley with stickers between planks for air circulation. Modern timber framing has been growing in popularity in the united states since the 1970s. A knot is essentially a discontinuity in the timber and hence a place of weakness. Seasoning when a tree is initially cut it is extremely wet, with 85 per cent water content. Methods of natural air seasoning of wood timber how to. Seasoning is the process of drying moisture from timber. Wood drying reduces the moisture content of wood before its use. Seasoning is the commercial drying of timber which reduces the moisture content of wood. Greensawn timber should be protected from sun and wind prior to filleting. On about 300 mm high platform timber balks are stacked as shown in fig. One of the best of these is to immerse the timber in water as soon as it is cut down, and after it has remained about a fortnight in water, but not more, to take it out, and dry it in.
In this method, logs are stacked upon one another in assemblies with space provided in between the logs to allow circulation of air. Methods of seasoning air seasoning natural kiln seasoning artificial. The links below will take you to information and worksheets on the preparation of natural wood, after. Over a period, in a natural process moisture content reduces.
Width and height of stack are restricted to about 150 cm and 300 cm respectively. Over a period, in a natural process moisture content. Block board is made up of layers of natural timber up to 25mm in thickness, glued together and veneered. Instead of boiling water hot steam can be circulated on timber. Water seasoning on account of the time required to season timber in the natural way, various methods have been tried to effect the same purpose in a shorter time. The 5minute video explains how natural wood is prepared for use, after it has been seasoned. Timber is seasoned to dry out the timber to bring it to a usable and workable condition. Kiln seasoning is an important type of artificial seasoning in which the timber is seasoned by the use of a forced draught of warm air in which brings about a rapid reduction in moisture content.
When the drying is done in a kiln, the product is known as kilndried timber or. Wood that is dried below 20 percent moisture content is not susceptible to decay or sap staining. Oct 22, 2017 advantages, wood, wood seasoning, shallow there are many reasons for drying wood, improving of properties of wood to be used for construction is the main aim. Regular wood seasoning is done by air drying in conditions below 18 percent moisture.
Advantages of natural seasoning of wood aboutcivil. Natural seasoning air seasoning in a shed with a platform of height 300 mm timber is stacked. Care is taken to see that there is proper air circulation around each timber balk. Seasoning of timber from day to day, most people have some contact with seasoned timber. Wood drying also seasoning lumber or wood seasoning reduces the moisture content of wood before its use. Timber framing is a style of construction which uses heavier framing elements than modern stick framing, which uses dimensional lumber. In this method, seasoning of timber is carried out by natural air and. Woodworking when wood is used as a construction material, whether as a structural. Seasoning seasoning is the process of drying moisture from timber. Natural seasoning is performed simply by exposing the timber freely to the air in a dry place, sheltered, if possible, from sunshine and high winds. In this method, seasoning of timber is carried out by natural air and hence, it is also sometimes referred to as air seasoning. This document has been scanned from hardcopy archives for.
This is a process of natural seasoning of timber that gives good results with logs of freshly cut trees. There are mainly two methods of seasoning of timber. Seasoning is the controlled process of reducing the moisture content mc of the timber so that it is suitable for the environment and intended use. It takes more than six months for timber to season in moderate climates. At first, a platform is required that is built on the ground at 300mm height above. The process has undergone a number of refinements over the years that have made it more efficient and reduced the quantity of wood that was damaged by drying too quickly. Here also different methods of artificial seasoning are there and they are as follows. Care should be taken not to expose the freshly converted timber stacked for seasoning to severe winds or to sun. When wood is used as a construction material, whether as. If wood is cut to size before it is seasoned, it will shrink during drying and thus be undersized in its final form. Natural seasoning i the timber in log form is not usually fit for. Methods of natural air seasoning of wood timber how to do. Free unfinished flashcards about seasoning of timber. Seasoning is not always uniform in all the sections of timber.
Removal of moisture from timber so as to be in equilibrium with moisture in surrounding atmospheric condition, where timber is likely to be used is called as seasoning of timber. Lamin board is made up of layers of 5 7mm strips of natural timber glued together and veneered. Followings are the reasons to perform timber seasoning. In place of sap, the cells get filled with ordinary water. After artificial seasoning the wood becomes harder, whereas in natural seasoning the wood becomes soft. Before the timber can be used a large part of the moisture must be removed. So, artificial seasoning of timber is developed nowadays. This is simply the weight of water contained in a piece of timber compared with the weight of actual woody substance in the same piece. Care is taken to see that air can circulate around each timber balk. There are various types of defects in timber as a construction material. The process has undergone a number of refinements over the years that have made it more efficient.
Feb 12, 2017 air seasoning involves the stacking of sawn timber on raised foundation with the help of crossers battens in a clean and dry place. Dec 23, 2015 removal of moisture from timber so as to be in equilibrium with moisture in surrounding atmospheric condition, where timber is likely to be used is called as seasoning of timber. Air drying airdrying is the drying of timber by exposing it to the air. The links below will take you to information and worksheets, on the worlds forests natural. The roof and two other sides keep the timber relatively dry. In a perfect seasoning process, stress is kept minimum by controlling the.
A chemical seasoning agent for wood consisting essentially of a concentrated aqueous solution of a hygroscopic organic chemical subject to attack by microorganisms and sufficient of a watersoluble chlorophenolate to prevent the growth of microorganisms in and on residues of the hygroscopic chemical as deposited on the surface of the wood. Seasoning of timber natural seasoning artificial seasoning water seasoning. Wood shrinks across the grain not along the grain when it dries. So, stress is developed due to the difference in shrinkage. In this technique timber is immersed in water and then water is boiled for 3 to 4 hours.
So, platform is built on ground at 300mm height from ground. Seasoning of timber is done to fulfill some specific requirement. Seasoning of timber is the process by which moisture content in the timber is reduced to required level. It is normally placed in a hut building, with two sides open to allow air to circulate. Air seasoning is carried out in a shed with a platform. Artificial seasoning of timber, civil engineering, assignment. When the drying is done in a kiln, the product is known as kilndried timber or lumber, whereas air drying is the more traditional method.
Seasoning is the name given to the methods of drying timber there are two methods by which timber can be dried. It also reduced the quantity of wood that was damaged by drying too quickly near the ends in air. Timber, lime, brick and mortar study notes for civil engineering. Papers past newspapers clutha leader 18 april 1884. By artificial seasoning, timber is seasoned with in 45 days. The width and height of stack are restricted to about 1. The technique of airdrying consists mainly of making a stack. Provide free circulation of air so as to allow moisture to evaporate. Trees gives us the timber which is converted into required form and finally used. There are multiple advantages to having wood artificially seasoned that relate to the quality, strength and cost of the wood. The timber is laid out as seen in the diagram below.
The different ways that seasoning in wood can be achieved. Advantage depending upon the climatic conditions, the moisture content of ward can be brought down to about 1020%. Drying defects are the most common form of degrade in timber, next to natural problems. Timber, lime, brick and mortar study notes for civil. Width and height of stack are restricted to about 150 cm and 300 cm.
Squared timber does not rift or split so much as that which is round. The ends of individual pieces must be coated with a moisture proof composition. The timbers originally were tree boles squared with a broadaxe or adze and joined together with joinery without nails. Felling, conversion and seasoning of wood engineers. Natural seasoning may be water seasoning or air seasoning. We need to reduce the mc of timber for the following reasons. To get timber, the trees are knocked down or cut down or caused to fall to the.
Timber loses both in dimensions and weight by seasoning, as shown in the following table of experiments, instituted in order to ascertain lhe weight of a cubic foot of different ldnds of wood,theforeign when first imported, those of the growth of england when felled, also tle weight of. Seasoning of timber artificial and natural methods. Fungal discolouration of the timber can occur very quickly, especially if sapwood is present. The basic principle is to stack the timber so that plenty of air can circulate around each piece. In this method, the seasoning of timber is carried out by natural air and hence it is also sometimes referred to as air seasoning. When timber is felled, the sooner it is removed from the forest the better. Only durable heartwood can be block stacked for any period of time.
This process of seasoning timber is the best as it gives very strong and durable timber, but it is extremely slow. Aug 28, 2016 the 5minute video explains how natural wood is prepared for use, after it has been seasoned. These defects in timber can be due to natural forces, fungi, insects and during seasoning and conversion. One of the most successful ways of wood drying or seasoning would be kiln drying. Seasoning is effected by natural and artificial means. Seasoning is the process of drying lumber either in a kiln or air drying to an appropriate level of moisture for woodworking and other commercial uses. Pinus radiata, family pinaceae, the monterey pine, insignis pine or radiata pine, is a species of pine native to the central coast of california and mexico guadalupe island and cedros island p. The purpose of seasoning is to reduce the moisture content in the. Types of these defects in timber is discussed in detail.
Stacking and airdrying of timber requires care and attention to detail for good results. Jan 21, 2015 there are two methods of seasoning of timber. Types of defects in timber as a construction material. In this article, youll know 5 best methods for seasoning of timber and wood. On the cut board, it is most easily marked by its conspicuously darker appearance and harder character. Seasoning is the reduction of moisture content of timber to that of thesurrounding air sydney area approx. During seasoning of timber, exterior or surface layer of the timber dries before the interior surface. On about 300 mm high platform timber balks are stacked. Felling, preparation of natural wood and seasoning. When the drying is done in a kiln, the product is known as kilndried timber or lumber, whereas air drying is the more traditional method there are two main reasons for drying wood.
Artificial seasoning kiln seasoning compartment progressive explain what happens during the kiln seasoning process. In other words seasoning of timber means getting rid of the sap and. Water seasoning this is the natural method of seasoning in which the timber is immersed in water to remove the sap of timber. Kiln seasoning is carried out in a thermally insulated chamber, a type of oven, that produce the appropriate temperatures to complete the processes, such as hardening, drying, or chemical changes. May 11, 2007 the traditional method of seasoning timber was to stack it in the air and let atmospheric heat and the natural air movement remove the moisture.
The traditional method of seasoning timber was to stack it in the air and let atmospheric heat and the natural air movement remove the moisture. By seasoning, generally, the moisture is reduced to about 15% where new cut woods bear about 50%. It may be supplied either roughsawn, or surfaced on one or more of its faces. To get timber, the trees are knocked down or cut down or caused to fall to the ground. Water seasoning logs of timber are immersed in water stream such that larger portion is placed upstream. The timber is stacked with wide spaces between each piece horizontally, and with strips of wood between each layer ensuring that there is a vertical separation too. The width and height of each assembly is restricted to about 2 m and 3 m respectively. Natural seasoning gives good results but takes more time. The traditional method of seasoning timber was to stack it in air and let the heat of the atmosphere and the natural air movement around the stacked timber remove the moisture.
The 6minute video explains the felling harvesting of natural woods, rough cutting and seasoning. The stack must be raised to a height of about 3mts. A knot marks the position of growth of a branch on the tree. Reduction of moisture content along with improving some qualities before the use of woods is called seasoning of timber. Seasoning of timber reason methods benefits civil engineering. Faulty method of seasoning causes serious defects in woods. This method consists in stacking the sawn timber in a dry place, should be made 300 to 450mm above ground level. Its silviculture reflects a century of research, observation and practice. More than half the weight of freshly cut timber consists of moisture or sap.
Condition shady drying agent air the rate and quality of seasoning depends on climatic factors such as. To make a correct percentage of shrinking of woods. The natural method of seasoning is the type of seasoning process that is carried out with the aid of natural factors mainly air and water. Felling, conversion and seasoning of wood engineers gallery. The timber is often dried to 1012 per cent for indoor use through a process called seasoning. When the logs are placed in running water, the sap from the cells can be easily washed out. Hooke parks timber seasoning shelter is a canopy for the storage and airdrying of timber. Artificial seasoning is the process by which lumber is dried using manmade devices such as a kiln.