Since each truss is a complete frame trusses do not use a common ridge board and the purlins along with the roof decking provide lateral support.
Function of wall plate in roof.
A wall plate or pan is a timber usually 4 by3 that sits on the inner top course of brickwork and the ceiling joists and rafters are fixed to it it can be repaired but is best done by a joiner as.
Roof slope is the amount of change in height as a ration of horizontal distance traveled usually expressed as inches of rise per foot of horizontal run or cm of rise per m of horizontal run.
As the mortar does not bond the wall plate to the wall steel straps are used to ensure that the roof structure remains secure.
Trusses are set onto the walls of a house and are tied together with horizontal boards called purlins.
Ceiling joist ceiling joists are the horizontal beams that run parallel from one wall to the opposite wall of the structure.
Generally wall plates are in lengths of not less than 3 m.
Definition of roof span.
These are typically 1 2 m long with a cranked end and are fixed to the wall plate at 2 m centres.
Definition of roof slope.
Will all be fixed to them.
These are fixed to load bearing walls using galvanised steel straps.
High winds can damage or remove the roof s shingles.
Fitting roofing wall plates top plates setting out squaring levelling and fixing strapping gable and hip roof wall plates for rafters joists and roof trusses getting the wall plates or top plates as they are sometimes called right is important because all the ceiling joists roof rafters hips etc.
A second layer of dimensional lumber is always fastened to the top plates of the erected walls so that no joints overlap providing greatly increased stability.
Couple roof couple roof under pressure.
Upper wall plate top plate or ceiling plate upper wall plate which is fastened along the top of the wall studs before the wall is lifted into position and on which the platform of the next story or the ceiling and roof assembly rest and are attached.
Normally a roof span is the same as the building width between the outer edges of the wall top plates.
When subjected to any type of load or force acting vertically downwards the rafters will move outwards at their feet thus exerting thrust to the walls forcing them outwards and causing possible failure of the wall structure.
Once the decking and roofing are installed a truss roof looks just like a stick framed roof.
Wall plates distribute the loads evenly over the load bearing walls.
As the first line of defense for a structure acting like a huge umbrella in receiving and deflecting all the potentially harmful weather that a structure would otherwise receive a roof itself normally sustains damage.
