Roof Trusses Vs. Rafters: The Key Differences Between Them
When beginning a construction project, one of the key decisions that need to be made is how will the roof be constructed. The question is, do you use loose timbers or Trussed Rafters. A decision which can affect the construction of your complete building.
Here is a guide to help you pick the right solution for you.
Are Trussed Rafters cheaper than a site cut roof?
When looking at the price differential of trussed rafters and loose timbers, a truss solution, although using smaller timber sections will generally, for the supply element, be slightly more expensive. This is down to the prefabrication off –site of the roof structure. The Installation is quicker with the provision of detailed drawings supplied with the roof pack and therefore reducing considerably the on-site costs.
In comparison, an on-site cut roof generally leads to more waste material due to stock lengths being limited which translates into an increased cost. A site cut roof also generally requires an experienced carpentry gang and an extended time to install the structure which may take weeks instead of days again increasing costs. On the majority of structures, a Trussed Rafter roof will be more affordable than a site cut roof.
Which is stronger: site cut or Trussed Rafters?
A Trussed Rafter is an engineered solution to creating a roof. It therefore creates a very strong product which is capable of spanning a distance far greater than a comparable timber section used on its own.
A loose rafter, even of greater dimension than a trussed rafter, on its own is not capable of achieving the large spans of a trussed rafter. It will require additional load bearing supports along its length ie loadbearing walls or Purlins. Loose cut roofs are however great for small spans such as small lean-to extensions on existing dwellings, sheds, etc.
However, when engineered correctly a loose cut roof will still perform to the same standards as a Trussed Rafter roof.
Choosing which one is best for your project depends on the size of project. Loose cut roofs are best for smaller projects but generally Trussed Rafters are ideal for those who are building a new dwelling.
Which one looks better?
A Trussed rafter is a fully engineered product and as such does not have the architectural advantage of being able to be left exposed. A variety of shapes can be achieved but the ceiling must realistically be clad. A cut roof however can be engineered to show exposed rafters, purlins, joists which may be required to give a more “open feeling “in parts of a new building or extension.
Which is more environmentally friendly?
Both Trussed Rafters and loose cut roofs have a minimal impact on the environment. A Trussed Rafter and Loose Timbers are both created using engineered timbers from sustainable sources and generally manufactured using reduced levels of emissions and pollution. Trussed Rafters may have a lower impact on the environment as they are manufactured off-site to reduce the amount of waste created whereas a cut roof, by its very nature, is hand built on site creating waste which will need to be removed when the project is completed.
Which is best for complicated construction projects?
If you are planning on building a custom ceiling or have a complicated roof in mind you will want a system that is versatile. Trussed rafters have a standard design shape but a complex shape can be produced by experienced designers. If you require an attic room this can also be achieved in Trussed Rafters.
Some designs do however occasionally become too complex, and an experienced engineer may be required to create the complicated design from loose timbers. In some cases there may be an amalgamation of both Trussed Rafters and loose timbers to complete the required solution.
Choosing between both options can seem like a challenge and a big decision as you will want to ensure you make the right one. Think about what you need to do with the roof, whether you need an attic to transform in the future and how much you want to spend on the project.
Trussed Rafters have many benefits and variations and Pasquill are one of the UK’s number one off-site Trussed Rafter manufacturers.
GET IN TOUCH with your local Pasquill Design Centre for more information and guidance on your project.