Fastening plywood gussets
Hi, I will be fastening plywood gussets to my 2 by 6 rafters to deepen the bays for additional insulation in my attic. The plywood is 3/4 inch thick. Gussets will be 11 inches long, mounted onto 4.5 inches of the long side of the rafter and allowing me to deepen the rafter by a further 6.5 inches. I have 3 questions.
1. How to fasten the gussets? Naively was thinking of 2 inch long screws. Then I read screws are more likely to break than nails. Should I use 5d or 6d box nails? Use maybe 3 nails per connection with rafter?
2. How wide to make the 11 inch long gussets? I was thinking about 6 inches. Is that width strong enough?
3. How far apart to space them? I was thinking of about every 3-4 feet. Putting them on alternative sides of the rafter.
The gussets will hold 2 by 2s to which drywall will be fastened. Pretty basic questions, I know. I have not done this before. I do appreciate your views.
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