Softwood Roof 75% Complete – green oak barn

Thursday 29/4/21

After putting up the first three short jack rafters yesterday, I realised that I was going to need the scaffolding tower to safely install the two longer jack rafters of each jack rafter set. But before moving the tower into the lefthand bay I decided to leave it where it was and use it to install the common rafters on the front and rear of the roof. I then moved the tower into the lefthand bay and installed the jack rafters. This is captured in this time lapse.

If you want slow the time lapse down, view the video on YouTube and use the gear icon to reduce the playback speed.

This is how things looked at the end of the day. Just the jack rafters on the right side of the roof are left to do.

Softwood roof 75% complete

Just a couple of things to note.

Positioning of the jack rafters
I’d cut the jack rafters to length according to the roof plan with the required plumb cut and bevel. This meant I could place the birdsmouth on the wall plate and move them into position against the hip rafter. To help with this process, and provide some reassurance, I made an improvised square by attaching a piece of straight, scrap plywood to my roofer’s square with mini clamps.

Improvised square

I was able to hook this over the arris of the wall plate to give reassurance that the jack rafter was in the right location at right angles to the wall plate.

Improvised square in use

Rafter to wall plate fixings
Just  to say that I am really pleased with the way these fixings are working.

Rafter fixings
Timba screws

I’m drilling through the rafter with a long 6mm auger bit and allowing the fixing to ‘self tap’ into the green oak wall plate.

Tomorrow I should complete the softwood roof.




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2 Responses to Softwood Roof 75% Complete – green oak barn

  1. peter boxer says:

    Hi Simon. Really pleased to have found your blog which mirrors a project I’m also involved in as I have just raised the oak frame for a 7 x 3m summer house. I too aim to use softwood for rafters and am puzzling over how to fix the birdsmouth into the oak wall plates. I have tried 4″ stainless screws as replacement toe-nails with some sheering even with pilot holes and wonder at your choice of the timbascrews? My concerns are that if either my stainless or your high grade steel fails over time the roof itself will risk becoming unstable – really any advice would be very welcome. All the very best Pete

    • Simon Berry says:

      Hello Peter

      Sorry for the delay, I’ve only just found your comment.

      I’m no expert on screws but I do know that stainless steel screws shear quite easily.
      The way I used Timba screws was as follows:

      – I drilled a 6mm hole all the way through the softwood rafter
      – plugged the first 10mm or so with tallow
      – used an impact driver to drive the screw into the green oak wall plate (with no pilot hole)

      I didn’t have any of the Timba screws sheer off in the process. Initially, I didn’t use tallow but found that I could not easily remove the Timba screw unless I’d used it – I had to use a socket set spanner which put a hell of a strain on the screw. Because of my workflow, I had to screw all the Timba screws in and then remove them as I built the softwood roof with the wall plates assembled on the ground and then had to dismantle it before reassembling it once the frame was up.

      I guess you will have found your own solution by now – if so please let me know what it was.

      I’d love to see pictures of your project. I will email you so you have my address.



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