Today, timber frame construction offers the strength and beauty of the timber frame tradition with modern improvements in insulation, design, and more.
While there are many timber frame companies dedicated to developing new structures, there are also companies committed to preserving historic ones. TTRAG members meet annually in a location rich in historic timber structures, present illustrated talks, and follow a historic buildings tour. In addition, the group produces an annual public conference. Find books on the craft and history in our bookstore.
Toggle navigation. Historical Practices. Extreme care must be taken while using the steaming method because it requires long periods of steaming to make the wood pliable enough to bend as per the requirements Johnson, n. If inadequate steaming is done, the wood might suffer permanent damage as a result of breakage during the process. As the idea of steaming the wood is to enable the user to bend the wood without breaking it, there are several reasons why the wood might break whilst in the steaming process Blaustein, If the wood being used is too dry, it may be difficult to get it soft so as to bend it.
In addition, due to the fact that certain types of wood can bend up to a certain angle or curve, forcing a different type of wood beyond the possible curve might cause it to break and cause permanent damage to it. The wood might break if it was not adequately heated or it were not straight enough Wood Bending and Forming, This implies that many factors must be considered and the wood to be steamed chosen wisely if the procedure is to yield the anticipated results.
To prepare for the procedure an individual requires a reliable heat source, a hose to carry the steam to the steaming area, a container to store the heated water and fitting screws. A kettle can be used to hole the hot water.
These requirements may be required in different lengths depending on the length of the wood to be bent. For instance, the pipe is cut according to the length of the wood in addition to the fittings sizes Johnson, n. The pipe to transport the steam is glued from either side and a single hole created to allow the steam to escape. If the holes are not made, the pipe may burst. Two additional holes are made at approximately five inches apart and a stainless steel bolt pushed through the steam pipe.
This preparation allows the wood to be on a suspended position during the procedure and not be in contact with the pipe How to Make Wood Bend, n. This enables the steam to penetrate the wood from all sides making it possible to steam adequately.
To avoid marking the wood during the procedure, it is essential to keep the metal away as much as possible to avoid contact.
The holes should be on the correct size in that they should not be too wide or too narrow and must be sealed with silicone. Glue laminated timber also commonly referred to as Glulam, is an advanced and versatile construction material used in both commercial and domestic construction projects. The major applications for this product include increasing design values in addition to ensuring improved product functioning Timber Structures, Perfect performance enabled by this product improves its market competition against other products.
The product is also product competitive besides being high quality. Glulam can be used in construction of simple beams to soaring arches used in stadium roofs extending above feet. Glulam composition consists of carefully chosen wood laminations also known as lams in addition to moisture tolerant adhesives Pizzi, The wood laminations are selected as per their performance characteristics and bound together using the moisture tolerant adhesives.
The complete product of glulam is available from depths of 6 to 72 inches or even greater lengths of up to feet. The general idea behind glulam is the visible beauty and hidden strength where an adhesive is used to bond pieces of timber to be used in utilitarian and decoration purposes. North Americans refer to the laminating material as lamstock or laminating stock.
Glulam offers added advantage to the builders because it is abundantly strong and stiff Law, Additional, the material is stronger than steel on pound basis. The connections on glulam are made using bolts or steel dowels supported by steel plates making it strong enough to hold massive weight. The material also provides the best surface quality, which enables a wide range of application options in the construction area.
Glulam can be used in both straight components and when curved. This gives the material a unique characteristic that makes it favorable from other options. Glulam can be used in many construction areas that include tied rafters, tied arches, curved portals, curved beams and glulam trusses. The usage of glulam in the modern world is the advanced version of the traditional techniques used in the same that were developed during the 20th century. The process of glulam was first applied at the end of the 19th century in Switzerland.
The original name used for it is Hetzersystem. The glue laminated timber use increased during the Second World War when construction of military buildings, military aircraft hangers and warehouses was required in large. The process of glue lamination must follow specific standards so as to justify the precise or the perfect design.
Typical products produced through the process of glulam include domes, arches, girders, beams and rigid frames. The process is a major concern while constructing wood connections as it connects the wood together perfectly.
So as to come up with a perfect connection between the timbers, the designer must carefully consider on how to accomplish a smooth and desirable connection. During the Second World War, the resin glues were developed and production knowledge based on these products improved to make the industry flourish. The machinery used to produce glulam products is capable of producing structural member layers, which are larger than those that other plants can produce Blaustein, Practically, the glulam production machinery can produce as long and wide products as can be handled.
The horizontal columns are usually made when several pieces of timber are glued to form a single structure unit. The vertical counterparts are made when the laminations are at right angles to the natural pane. Here, the glue lanes are perpendicular to the length of the cross section.
The strength of these products is usually enhanced through using a reliable binding material and reinforcing using steel plates and bolts Blaustein, Due to the fact that large timber uses have caused environmental worry, efficient usage of available wood has been emphasized and the process of laminating this wood to produce bigger products has enabled the usage of almost all the timber available for construction Timber Structures, Here, the glulam products are made from less attractive timber to make other stronger products that are stronger than other products made of solid timber.
The products from glulam are advantageous as compared to other products made of solid timber in several ways. First, the glulam products suffer less from defects as compared to timber products that develop many defects as a result of weather or moisture changes. The products of glulam are environmentally friendly as compared to other products such as concrete or steel products because they have minor energy requirements Bostrom et al.
Although this procedure also requires the user to apply many considerations, it is much easier and safer than the steaming method. Thin pieces of wood are used in this procedure. Sometimes pieces are glued together and used.
After the form or mould is ready, glue is spread on the pieces and they are stacked together in the form of the clamp". After the glue dries, the edges are trimmed. Glulam is made from both hard and soft woods species Hermawati, Massijayaand, Nugroho, Glulam products are classified according to strength.
The stress class system includes the soft wood glulam combinations. The horizontal glulam is the only product classified. It is then classified as either homogeneous or combined. The homogenous type refers to the laminated timber with lamination sections that are on the same grade in their entirety Hermawati, Massijayaand, Nugroho, The combined version is the type of lamination where there are different types of laminations in the inner and the outer sections. The most common choice for home building purposes is the framing appearance grade.
This mode is only recommended for usage in concealed areas. The industrial grade appearance form of glulam is applied on areas where aesthetics is not a major issue. The appearance of the industrial grade is better finished as compared to the framing grade. This is usually applied in areas that are not visible to the public. This is because this mode shows wood imperfection on the surface including knots and voids. The architectural grade is the most preferred when applying glulam as the exposed element in structures Forest Products Laboratory U.
This product shows a highly finished glulam product because the wood voids and imperfections are treated or filled so as to enable the exhibition of an architectural surface with a good surface. The premium version is used on special occasions especially in places where high concentration of individuals is anticipated Laminated Timber Architecture, n. The premium glulam is used on such occasions because it has smooth surfaces that result in a high quality end product Structural Glued Laminated Timber, n.
Glulam products that are pressure treated are used in such areas in addition to timber products that have been manufactured using naturally durable Glulam has many benefits that include providing a highly durable material and having a perfect insulation properties as compared to other products.
In addition, the finished product is lighter than other products such as steel. The finished glulam product is approximately one sixth lighter than concrete beams of the same dimensions.
For this weight advantage, the finished product ensures low transportation cost as well as handling costs. The material can also be made in large sections and long lengths.
The advantage that makes it attractive in the market is its resistance to fire Timber Structures, Here, if glulam and steel beams are put in similar fire conditions, glulam product would survive the situation better than steel would. This advantage reduces the risk of fire spreading fast therefore being highly advantageous. However, glulam products require care while handling. Interestingly, the method of timber framing and the styles of structures that were built depended greatly on the type of trees available in the region.
There is evidence to suggest that timber framing techniques were used all over Europe and in part of Asia during this time, where hardwood tree including oak and maple, are in abundance. In comparison, in colder climates such as northern Europe and parts of Russia, the log home was preferred, given that timber was quite tall in these areas. The ready availability of timber in EuroAsia is considered as one of the contributing factors to the rise of Western civilisation.
The quality of slow-grown old-stand timber such as Pinus Sylvestris that was cut inland and sent down river to the Baltic ports of Memel and Riga was recognised by architects and craftsmen of the period. Contemporary specifications for example by English architect Sir John Soane called for pine and fir from these ports, including Memel and Riga Fir.
Slow-grown timber with tight growth rings and vertical grain was used extensively for quality joinery such as doors, door-frames and box-sash windows. From the 17th century imported softwood timber was available from Norway and the Baltic, cut to size using water-driven frame saws.
This reduced transport costs and enabled carpenters to access timber with larger sections baulks. In the 18th century the use of softwood in carpentry for trussed roofing, trussed beams and trussed partitioning became commonplace. The trussed elements of 18th-century building construction were designed to be of a structural nature and were adopted as a result of architectural influences from Italy where a wider expanse of ceiling was fashionable in the principal rooms.
The midth century saw the publication of many illustrated books promoting new structural and decorative joinery techniques. The demand for affordable technical literature such as this demonstrates how 18th-century craftsmen and professionals became engaged in a quest for knowledge in the fields of construction and architectural detailing.
Conservation through repair is an ethic much spoken of, but with regards to the repair of external joinery of historical importance, many people fail to appreciate just how positive and permanent a well-executed repair can be. One of the most common historic external joinery elements is the box-framed vertical sliding sash window. Neglected rotten window frames are often seen as a burden and simply replaced.
However, they can usually be repaired the rot in softwood joinery is actually often the result of poor maintenance or previous sub-standard repairs , saving both money and well-made historic joinery. To encourage owners to repair where possible rather than replace, it is necessary for craftspeople and conservators to impart confidence in the longevity of a well-repaired item.
This requires the relevant knowledge to specify the correct repair materials and expertise in the appropriate craft techniques such as the scarfing and joining of new wood to old. Once a good repair is completed it will serve for as long as the original item is maintained and kept in working order. Given that joinery items can almost always be repaired, what is needed to achieve a successful repair? Quality of material Much of our historic joinery was constructed from wood that was slow grown.
This wood generally has a fine, close-grained texture and, because much of it was from old stands, it tends to be fairly clear of knots and vertically grained, giving it good durability and stability. Today, managed softwood plantations aim to produce timber as quickly and as economically as possible. This faster grown timber is not as durable as that from the mature trees that were more common up to the start of the 20th century. Much of the modern fastgrown softwood will be used in construction once it has been pressure impregnated with preservatives.
Generally this type of timber is not suited to quality repairs of historic joinery. The quality and closeness of grain of repair timber should match that of the original as closely as possible.
This will reduce differential movement at the junction of old and new wood. The last remaining virgin forests in the world are almost all protected, and timber which matches the quality of that used in the past can be difficult to find. A good alternative is Douglas fir grade no 2, clear or better. Selection is important and all repair timber should be chosen and inspected piece by piece.
Moisture content is particularly important. It is likely that the stocks sourced will have been kiln dried. At the inspection stage moisture readings should be taken of the historic joinery in the zones of sound wood, especially in the areas where the splicing of new to old is to take place. The moisture content in the selected repair timber and in the original wood should correspond to within one or two per cent to avoid subsequent movement. Craft practice Minimal intervention is a key principle of good conservation practice.
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