For pitched roofs flat roofs and ceiling joists.
Trada roof trusses.
The most common pattern is the fink or w truss designed for symmetrical double pitch roofs although there are a variety of shapes suitable for most roof designs.
Surveyors span tables for designing roof rafters.
Widely used for a range of building types trussed rafters are an economical versatile and straightforward solution to providing a roof to a building.
With roof trusses large spans and challenging roof contours are no barrier to creating innovative eye catching design solutions.
Many tra members specialise in the delivery of commercial trussed rafters supplying roofs for hospitals supermarkets schools and many other large public spaces and designed to the eurocode 5 design code for best.
The tda trusses were built on site using toothed plate connectors and were based on standard designs that were published by the timber development association tda the forerunner of the timber research and development association trada.
They have been popular since the 1960s.
Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings.