How Important are Purlins?

[ashthekid]

Just how important are purlins in a timber frame roof & wall structure with vaulted  ceilings and two king trusses in?

[markc]

Pulins serve two purposes, one to support the roof itself and second to stabilize the trusses

[George]

Purlins are integral the the roof structure and often form part of the restraint to gable walls.

 

In a king truss roof they will be halving the span for the rafters.

 

In a word - 'very'.

[Russell griffiths]

It all depends on the design, you can build a roof with no purlins, no problem, but having a roof designed with purlins and then not putting them in. 

Well that’s an altogether different situation. 

[Temp]

2 hours ago, George said:

Purlins are integral the the roof structure and often form part of the restraint to gable walls.

 

In a king truss roof they will be halving the span for the rafters.

 

In a word - 'very'.

+1

 

Best get input from an SE before doing any modifications.