purlin joint

[magico]

hi can any of you qualified joiners advise me on how to join purlins together so BC don't have a problem. having a 1st floor side extension on my 3 bed semi. the roof has a hip but after extension would be made to a gable end. need to extend the 2 purlins and the ridge board. Butt and splice or half scarves maybe? the purlins
are supported on the internal walls built up into loft space

 

[Deleted member 174758]

This is a structural element and the BCO will want top see evidence of a structural engineer having done the calcs, I feel. He/she (the SE) would also be able to advise on suitable jointing techniques, although something like 2m+ equivalent size fishplates, bolt, square washers and star washers in the joints may well be called for. TBH spliced joints are difficult enough for a pro to achieve in workshop conditions - on site they are even more difficult, and no structural engineer in the UK would sign off on them as they are impossible to quantify. So you are barking up the wrong tree here, I feel. I've seen a lot of badly done ones in the past which makes me highly sceptical of their use

 

[Ian H]

I bet your SE will design the roof with a steel purlin (with timber on top) going from your new gable to your old side wall. Then in fill above the old hips with new rafter sections.

Or are you pulling the hips out altogether?

 

[magico]

thanks for replys guys...just got thrown a curve ball. Architect just rang saying the power that be would like to know...would we be open to hipped roof on extension now. Asked them is a gable 100% out of the question......basically yeah. So basically now I have to remove the hip , extend and hip the roof again. any good framing and roofing books out there to get to grips in my mind

 

[Ian H]

Are you doing a loft conversion at the same time?

 

[magico]

no mate..was planning on doing so in the future but the lack of a gable end now....thinking not

 

[Ian H]

You could gable what was the original house and have the hip over the extension. That way you could still have a decent sized loft.

 

[foxhole]

Are you doing the roof yourself, I got in a roofing carpenter, did the lots on his own in 3 days including dragging up the 3x9 purlins [6m]on his own, £200 per day but cheaper than neighbours who had a gang of carpenters on his roof for over a week [and half the work]. Amazing chap , and in his 60's.

 

[magico]

Sorry been on holiday... yeah planning on doing most of the work myself. My lads a brickie so between us I think we'll manage. Just waiting for changed plans which he's dropping off today. Be in touch guys