Oak Trusses
Trusses have been used for millennia to hold the roofs over our heads and the king post truss is both strong and imposing like a giant piece of furniture in your home, both functional and stunning to look at, once we have manufactured the truss we can also install the roof beams and ridge beams and finish the oak with an adze finish which really makes the grain of the timber stand out.
Oak King Post Trusses
The King Post Truss is by far the most common truss we manufacture, built using four components: the tie beam, the King post, two principle rafters, and two braces. The component parts are manufactured so it only really goes together one way, which is part of its strength, The King post is housed into the tie beam with a mortise and tenon Joint, the king post is normally waisted in the middle so its slimmer through the centre, this also gives a dove tail at the top where the principal rafters meet, so as the downward forces push on the principal rafters (in compression) the truss gets stronger, also at the lower end of the King post, the post has the opposite dove tailing which will house the braces, the braces are also in compression, where as the actual king post is now in (tension) as the forces are trying to pull the king post apart, just think about what force it would need to do this, take a lollipop stick you can easily snap it along its length but, try to pull it apart in opposite directions, it's virtually impossible. Each joint in the King post truss, and there are nine of them, will have one or two Oak pegs through the joint, the holes will be drilled offset which means one of two things, firstly as the peg is driven into the joint it will pull the joint together and hold tight the joint with the weight being taken on the shoulder of the joint and not on the tenon, secondly because the holes are offset this will also serve to increase the pressure on the joint and keep pulling the joint together as the timber dries and shrinks, this is known as a (drawbore) I can’t tell you how satisfying it is when you are assembling a truss for the first and hopefully the last time and you are the stage of the build where you are simply knocking a peg into its home, it's basic but strangely satisfying, also it can be a nervous time for the carpenter. The King post truss was historically used in a build with a step pitch as no one was too concerned with height restrictions back in the days of men wearing tights and carrying swords round with them, but in our modern times the king post truss can also be used successfully in a roof with a shallow pitch, however our engineers usually require extra stainless steel fixings which are normally hidden but, sometimes our customers have asked us to make the fixings visible, offering a contrast twixt old and modern.
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oak framed hip, complicated carpentry to support roof corner on a farm renovation project
Replacing failed roof truss with traditional hand made Truss made from Douglas fir
Failed roof truss due to rot need to be replaced while leaving the roof intact
Oak Queen Post Trusses
The Queen Post Truss is less common, but has a massive advantage over a King post as rather than a single post in the centre, it has two posts from the tie beam to the principal rafters. This can allow for easier access and a door way in the centre if you want to utilise the roof space, also the span can be greater than a king post truss.
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Curved Tie Oak Trusses
The Curved Tie Truss is basically the same as a King Post Truss, however the central arch of the tie beam is raised, offering more head room. We source trees that have grown curved, something which is getting harder to find but working closely with local tree surgeons and saw mills we can still get them. The grain is now running in a natural arch, so when we cut the timber, which is a process that can only really be done by hand, the carpenter will follow the grain so to maintain the strength in the timber. Theses trusses look amazing and are our favourite type, probably because of the challenge, think of it as a carpenter's signature dish.
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crane operation as the trusses get installed
trusses in the air as the crane lowers the curved tie beam truss into place
Calder Oak, Altham Corn Mill. BB5 5UP
Carpenter offers the ridge beam onto a raised tie truss
first fix installation of the raised curved tie beam truss made for English Oak
Calder Oak using curved oak to manufacture this truss by hand
Glazed Oak Trusses
Glazed oak king post trusses. In medieval times glazing a timber frame or gable end truss would have not been possible but, today’s glazing systems allow for this and offers the potential to flood your building with natural light. Our preferred method of glazing is known as direct glazing, which allows for the timber to move and shrink, and is the most common method currently on today’s market.
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Asymmetrical Oak Roof Trusses
Asymmetrical truss. This build was a challenge and needed stainless steel fixings in addition to the traditional joints and oak pegs. The current truss which is already in looks like at sometime in its life has failed and has been reinforced using a steel RSJ. The wide pitch and the asymmetrical design puts quite a lot of strain on the principal rafter.
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Douglas Fir Roof Trusses
Douglas Fir is a great way to keep your project cost effective and keeping within a budget. While oak is still our favourite choice Douglas Fir offers some advantages and from an environmental point of view is a winner. The timber cuts and presents itself very well and is one of the most durable soft woods available due to the natural resins found in the timber.
