SPECIFYING ROOF & FLOOR STRUCTURES
When we think of build systems, the focus is often on walling techniques – but the roof and floors play a vital role in achieving the design and performance goals you want
Whether you’re working with a package provider who’s delivering the whole house shell, or specifying your roofs and floors separately to the walling, get to grips with the details early in the process. That way, you can maximise the opportunities different systems offer, ensuring that everything is as clear as possible for your build on site.
ROOFING
Most new houses are built with standard premanufactured trusses, which can be craned into place ready to be covered in a membrane and battened out for your roof covering. This is typically the cheapest solution whatever walling system you’re using. However, there are alternatives such as attic trusses or SIPs (structural insulated panels), that could be a better fit, depending on your house design.
Timber trusses
The simplest and cheapest roof structure is typically a Fink truss, which is engineered to use the minimum amount of timber. They require a W-shaped network of supporting struts – meaning the loft space is only really viable for storage purposes. As a result, many self builders choose attic trusses, which use larger main timbers to remove the internal web of supports and enable in-roof living space. “We often recommend this as, while it’s more expensive, it adds value by providing additional habitable rooms,” says Luke Roberts, MD at Donaldson Timber Engineering.