Hi @nixybrown,
Thank you for your question about installing a pelmet for your outdoor blind. I think your idea is great, but you will need to change your material slightly.
Your plan to use a weatherboard and angle brackets is good, but a standard weatherboard is fairly thin, so you wouldn't find a screw that will hold it with sufficient strength. I'd suggest using either 90 x 30mm LOSP or 138 x 30mm LOSP as there is more depth in the timber to screw into.
You'll need to ensure the angle brackets are firmly attached to the timber behind the eaves. You can use a stud finder to locate the timber behind the eaves. You'll want to use an angle bracket on every available timber.
You can use Zenith 10G x 50mm Galvanised Type 17 Countersunk Head Timber Screws to attach your angle brackets to the eave timbers then use 8G x 25mm Galvanised Countersunk Head Timber Screws to fix the pelmet to the brackets.
To add strength to the structure and conceal the ends of the blind, you can also add a mitred corner and returns on each end of the pelmet. If they don't line up with eave timber, you can use Ramset 16mm Hollow Wall Anchors to attach an angle bracket to support the returns.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
