House Roof Building Today
House building today more than ever looks for economic saving, and although safety is always at the fore, cost savings and construction speeds are always sought.
Roofing a house is a major factor in its construction, and speed and efficiency have led to some 80% of houses built today using pre-manufactured roof trusses in place of traditional rafters to support the roof.
Roof trusses are factory designed and built wooden triangular frames, which are transported to the construction site once the house outer walls are finished, and placed, by crane, on top of them to put most of the downward pressure from the roof to those supporting walls.
There are several advantages of using pre-manufactured truss roofing, not least in traditional timber construction the possible differences between the carpenter’s ideas of satisfactory and the builders take on roof strength.
The trussed roof system is designed by engineers to meet each specific roof design and building regulation allowing roofing contractors to minimise build time, cutting costs and speeding up the construction process.
The trusses are manufactured in controlled conditions, without exposure to the elements, using consistent standards of timber.
They can be installed quickly, in many cases a single day, which speeds the construction process to make weather tight, keeping the elements out. This allows other trades to start internal work, plumbing, plastering etc., sooner.
The inclusion of computer designing, has allowed for almost any custom roof design and shape imaginable, allowing the possibilities of cathedral ceiling, cross gables etc. not being prohibitively expensive.
Unlike conventional roofing, trusses can span a considerable distance without the need for supporting internal walls, allowing for airier spaces if needed in planning.
A drawback of the system is, because the strength of the roof is designed around the performance of all of the interlocked trusses, it is inadvisable to alter the structure, thus jeopardising the roof’s integrity.
Roof Truss Construction
Two basic types of roof truss design are used in residential type construction, the flat truss or the pitched, or common truss.
The common truss is the most usually used, and is the familiar triangular shape seen on building sites.
There are variations of the common truss shape such as Fink, King post etc. with its size and configuration being determined by the load, span and spacing.
The flat truss has parallel top and bottoms, and is generally used in floor construction.
The flexibility in design has made the system first choice high density home building, allowing for individuality amongst what would have been uniformed monotonous development.