Hello,
Need advise please re new garage roof. My garage is approx 24ft x 10ft. It needs new joists, decking and felt. I also want to put a slight slope on it.
my questions are: do I buy rough-sawn or new wood for joists? Should the new joists be 6"x2" 16 inches apart? Or should the new joists be tapered say starting 8" x2" going down to 6"x2" to get the slope or do I just add furrings? If so what size? 3"x1"?, 2"x1"? If it's better to put furrings on the 6"x2" joists how do I attach them-normal screws, nails or decking screws? and how far apart should the fixings be on the joist? Also I'm puzzled how furrings on joists can support 18mm decking? Surely they won't be nowhere near as strong as a tapered unit? (I'm assuming the furrings are fixed on the top of the joists on the same plane/direction?)
Re the decking I'm thinking of using osb3. Do I use the basic osb3 or the T&G osb3? Do I leave a gap of 2-4mm for expansion(as the text books say) and if so how does that work with the T & G?
Do I fix the decking onto the joists with nails as some roofers appear to do or do I use decking screws?
Is it better to use spax decking screws cos they are more sturdy?
Apologies if there are too many questions here. If half of them are answered I'll be grateful.
Thanx
Need advise please re new garage roof. My garage is approx 24ft x 10ft. It needs new joists, decking and felt. I also want to put a slight slope on it.
my questions are: do I buy rough-sawn or new wood for joists? Should the new joists be 6"x2" 16 inches apart? Or should the new joists be tapered say starting 8" x2" going down to 6"x2" to get the slope or do I just add furrings? If so what size? 3"x1"?, 2"x1"? If it's better to put furrings on the 6"x2" joists how do I attach them-normal screws, nails or decking screws? and how far apart should the fixings be on the joist? Also I'm puzzled how furrings on joists can support 18mm decking? Surely they won't be nowhere near as strong as a tapered unit? (I'm assuming the furrings are fixed on the top of the joists on the same plane/direction?)
Re the decking I'm thinking of using osb3. Do I use the basic osb3 or the T&G osb3? Do I leave a gap of 2-4mm for expansion(as the text books say) and if so how does that work with the T & G?
Do I fix the decking onto the joists with nails as some roofers appear to do or do I use decking screws?
Is it better to use spax decking screws cos they are more sturdy?
Apologies if there are too many questions here. If half of them are answered I'll be grateful.
Thanx
