by Rafferty Roof Trusses
•
12 December 2019
Have you ever walked into an old building, looked up and marvelled at the large array of beams and wondered “what are they and what do they do?” Known as roofing trusses, these structures are specifically designed to support the roof of a building and are becoming an increasingly popular choice for many domestic and commercial property owners. As conventional rafters and joists have become less and less common in the construction industry, prefabricated trusses have filled the space, with around 80% of housing being built using this method. Being advantageous both for new construction and for clients looking to extend their property, roofing trusses can be a great investment. However, with a range of different roof truss designs utilising different materials and techniques, how can you be sure that making such an investment is right for you? As roof rafter and truss experts, we at Rafferty Roof Trusses Ltd know a thing or two about the industry. With this in mind, we decided to put together this handy guide on roof trusses in order to give you the lowdown on what’s right for you. What exactly does a roof truss do? In layman’s terms, a truss is an assembly of beams that creates a rigid structure; this construct is rigid thanks to two-force members acting as a single object. Using a triangular design, trusses have been used for bridge designs, flooring and, of course, roofing. While similar to rafters, a roofing truss is more complex, having a series of triangles within its main frame known as webs in order to supply a superior level of support to a structure. Although roof trusses are extremely popular today, you may be surprised to know that they’ve been used in some form of construction for as far back as even the Egyptians on their ships. Since then, this structural design has been used throughout the ages, from primitive lake dwellings in the early bronze age to the vast bridges found around the world thanks to the use of wrought iron and, in turn, cast steel. These days, truss designs can be found nearly anywhere you look due to the fact that they can offer a host of benefits. The benefits of quality roof truss design When it comes to the various benefits of roof trusses, the one that stands out the most is the amount of time saved. In comparison to conventional roof building techniques which can take precious time out of the construction process and are usually constructed on site, a quality truss made by an engineer can typically be installed in a day as everything is assembled in their workshop. By installing the truss this way, builders can significantly slash the amount of time spent working on the roof. Having the truss designed and assembled in house also offers the advantage of superior preservation. By minimising the amount of time your truss is exposed to the elements, the materials will be less likely to run into problems later down the line from excess moisture. Finally, it should be noted that a roofing truss is extremely versatile. Fitting nearly any custom roof design you can think of, a quality roof truss engineer will be able to construct a final product that perfectly fits your needs. Understanding the types of roof truss While all trusses offer a great range of benefits to a building, not all of them are the same, coming in a variety of shapes and sizes depending on the construction project. Because of this, it can be good to know what factors dictate the type of truss you will need for your build. Of course, your roof’s design and shape will be the main caveat determining the type of truss you’re going to need. From here, truss design for home building is split between two main subgroups known as flat and pitched. These can then be broken down into more specific truss types that can suit a variety of construction projects. King and Queen post trusses One of the most common types of pitched truss used in UK households is known as the king post truss. With the principle rafters and tie beam making a triangle, a king post is then fitted in the centre of the tie beam and connected to the roof ridge. As one of the most simple truss designs available, king post trusses are usually found in old barns, however, they can still be useful for new roofs with small spans. A queen post truss is somewhat similar to a king, however, with two vertical posts instead of one and a set of straining beams, they can offer a superior level of stability to a roof structure. This means that queen post trusses can be effective for roofs with a larger span than a king post truss. Attic Truss Also known as ‘room in a roof’ trusses, this design is becoming increasingly popular amongst homeowners looking to maximise living space in the attic without changing the footprint of the room, making it an extremely cost-effective option for buyers. An attic truss works by incorporating a floorspace into the design, meaning that the open space in the middle can be used as a great living space. This extra room can be used in a variety of ways, from extra bedrooms to a new lounge. Fink truss The most commonly used truss design here in the UK, especially for homes and other domestic buildings, a fink truss has an internal web in the shape of a W. This shape allows for a superior level of strength and stability, in particular for spans stretching from 5-9 metres, which covers the footprint of most domestic buildings. However, some fink trusses have been known to stretch to 14 metre spans, making it more versatile than you may think. Because of this, it’s always best to chat to a professional to ensure you get the right design for you. Scissor and raised tie truss For property owners looking to maximise the headroom of their attic space, a raised tie truss may be the answer. By raising the tie beam, it's possible to install a raised tie truss a whole metre above the wallplates, meaning maximum head height. Scissor trusses are similar to raised tie designs in that they increase headroom and works in roofing projects where a raised tie option may not be attainable. Steel roof truss or timber roof truss? Aside from the truss design you decide to go for, there will also be the issue of picking the right material. The two most commonly used are timber and steel, each boasting their own pros and cons. For example, a steel truss will last much longer than their wooden counterparts as they won’t succumb to rot. Steel trusses are also stronger and more easily moldable, however, will likely be more expensive overall. Also, if you’re looking for a certain aesthetic, a steel truss may look out of place in your living space, unlike a timber truss which can even enhance your attic’s look. Looking Quality roof truss design specialists? Get in touch with Rafferty Roof Trusses today While the above are some of the most common truss designs on the market today, this is by no means an exhaustive list. By working with a quality builder, you can take advantage of a range of truss designs that can perfectly fit your needs. Here at Rafferty Roof Trusses, we’ve helped countless customers with their roofing needs, designing and manufacturing bespoke products for nearly 20 years. Also supplying a range of roofing products, from slates and tiles to glulam beams, you can be sure that you’re working with the best. If you would like to learn more about how Rafferty Roof Trusses can help you, why not give us a call on 01422 377 551 or visit our website .