It's all going a bit Ting-Tong
Particularly as I've never made a roof before, I decided that I should follow Mike's First Rule of Rooves
I absolutely insist on level and parallel plates,And therein lies the rub. Just how level is level and how parallel is parallel.
And also how level does the top of the plates need to be ?
Because this is what I found and spent the best part of the day faffing about with little result.
First up, I went to try the laser level but it wasn't bright enough in daylight. So I waited for dusk, set it up and then glue-gunned some offcuts with the correct reference level marked on them and ready for the morning.
The result was that the far end was pretty much level with the other end but along the long sides, the level was out by up to 9mm. Being a bit of a perfectionist I set out to try and level them all up. Two hours later, I'd only managed one long side and it was then that I noticed that the top of the upstand..on which the birdsmouths will sit wasn't level. Again, not out by much...a few mm here and there but thinking ahead, the rafters will be visible and so I thought I would end up seeing the rafters not sitting down square. The reason for them not being level was that my plan to cut the long firring pieces down the long sides at an angle, sandwich the OSB on top and then fit the companion piece to the firring bit underneath to bring it back to level. Only it didn't. No idea but it threw the tops of the upstands out of whack.
Digressing slightly I am still glad that I did do things this way as I realised that if on the underside of the joists I fixed a skin of 9mm ply then my roof has suddenly become a torsion box.
Anyway I faffed around for another couple of hours and finished one side. You can see the packers jutting out as, obviously they can't go all the way through to the outside otherwise I'd not be able to bring the tops back level.
I then started on the other long side and applying the second part of Mike's Law, soon realised that the two long glulams weren't parallel. This one bows in at the middle by 10mm.
So I'm in a bit of a quandary as not being an experienced roof maker, just wondered what grief I'll be setting up for myself if I don't offset the upstands to compensate for the bow.
Hope that all makes sense.
If opportunity doesn't knock, build a door.