Fence House Roof Truss Company

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Self-Build common queries

It’s exciting taking charge of your own self-build. But, as anyone who has been through the process will know, it’s a steep learning curve, with roof trusses just one decision to make among many.

Roof trusses are a popular choice for most self-builders as they need less labour than other roofing methods. A self-build using trusses also has less need for interior walls, which is an obvious time and expense saving. One of the main advantages of using prefabricated roof trusses is they’re usually delivered and set in a day, meaning the interior of the building won’t be exposed for a long time.

That said, as with anything else in self-build, selecting and specifying your roof truss can be a complex process if you haven’t done it before. We’re here to help though, with years of experience helping self-builders to correctly specify their roof truss needs. Our team of experts is always on hand to help and guide you through each step of the process. We’re used to working with owners, builders, architects and anyone in between, meaning your roof trusses can be one thing you don’t lose sleep over.

We’ve pulled out some useful information related to common queries we receive, but if in doubt, please contact us; we’ll always be at your side throughout your self-build project.


What are the different types of roof truss?

Roof trusses are available in a variety of shapes and sizes and can be customized to suit virtually any roof design. One of the most common types of truss system is a pitched truss, also referred to as a common or fink truss, characterised by its triangular shape. There are a variety of truss designs and terms for common and other trusses too – don’t worry, most of them just represent different shapes and sizes of truss, as determined by the size, shape and load requirements of your roof. We’ve listed some of the common types of roof truss for you below.  And, if you hear talk of any of others, such as dual pitch, inverted or cathedral, don’t worry as we can explain them too!

Fink Truss -A fink roof truss is the most commonly used truss type, due to its flexibility and value for money. It provides a high strength structure with good load-carrying capacity, and can also be used as a support for other trusses.

fink truss

Attic Truss – an attic truss is a popular choice for creating additional living space in the roof, as the design removes some of the centre structure, by providing additional support at the sides and top.

attic truss

Raised Tie Truss – Raised tie roof trusses can provide more internal room height by being supported partway up the lower end of the rafters, rather than on the ceiling tie. They’re the ideal choice for “cottage” style builds.

Mono Truss – a mono truss is typically used where the roof is required to slope only in one direction. Traditionally, mono pitched roofs have been used for garages and lean-tos but increasingly people are opting for this design to give a modern look to their home.

mono truss


What's a roof truss?

Roof trusses are used to carry and support the weight of the roof deck and any materials used to cover the roof.  There are two main types of roof truss; pitched and flat. Pitched trusses are easily recognised; triangular in shape and giving that common “triangle hat” shape. Flat trusses, as the name suggests, are used to support flat roofs. All trusses have the same basic components. The outside framing parts are known as chords and the smaller connecting parts are webs. Trusses have bearing points where they rest on a load-bearing wall. They also have posts and tie beams, which provide support to the roof truss structure.


What does timber treatment include?

Timber can be treated to further protect wood from the elements, such as fungal decay and insects (a risk in South East England). The specific risk to your timber will be dictated by your geographic location and where the timber is being used in the construction. It’s an additional cost to have your timber treated (around 10% of the cost of your structure) and the process includes covering your timber with a preservative specifically designed to protect wooden structures from the elements.

What's the approximate additional cost for a room-in-the-roof system?

While the cheapest way of building a roof is with a standard roof truss, they don’t allow for future expansion. An attic, or room-in-the-roof truss, is specially designed to maximise space and allow for further room development. Attic trusses do cost more to buy; you can typically expect to pay between one-and-a-half times and twice as much as for a standard roof truss. However, an attic truss will add value due to the additional square footage, regardless of whether the space is finished.

What happens if I want to make a change to my roof trusses/floor joists/timber frame but they've already been installed?

We often hear this question, and it’s usually because an electrician or plumber wants to drill holes to fit wires or piping retrospectively. We’d never recommend carrying out this type of alteration without consulting us first; often we find we’re asked too late and serious damage has already been done. Roof trusses and joists support your building structure and any alteration to them by cutting or drilling compromises their structural integrity. The only way to avoid expensive repairs or replacements is to eliminate the need for retrospective work through careful planning that considers all of your build stages, including electric and plumbing.

What are your delivery timescales?

We offer a five day delivery service within the UK mainland following the approval of your design.

Do I need to treat my roof trusses/floor joists/timber frames?

There is no legislation that requires you to treat your timber, but some areas, such as the South East of England, have problems with beetle infestations that can damage the integrity of timber structures.