Working up a quote for customer on a 12×22 roof over a deck and hot tub area.
Got a price for trusses – about $425 delivered. However, I thought I could just stick frame it instead of wait two weeks for trusses. Customer would also like the look better I think.
If I’m only putting metal (whatever gauge Lowes sells) across 1×4 purlins on a 4:12 pitch would I be ok framing it with 2×8 rafters at 4 ft OCVB and a purlin every 12″?
Or do I need a 2×6 ceiling joist and rafter every 24″ OC? We are in Deep South Georgia (i.e., NO SNOW LOAD) and the normal house-type framing seems like a big overkill on this light of a roof.
Thanks.
MikeVB
Replies
I'd go with the 2x6 on 2' centers. Those 1x4s spanning 4' just seem weak to me.
Dave
I agree with Dave Mason about 24 oc framing. The heat alone would turn your 1 x 4's into pretzels on 48 oc framing. The deck outfit I work for builds a lot of roofed decks and we use 4 x 6 posts notched and through bolted to a continuous doubled up 2 x 8 header to carry the roof load. A not terribly expensive option would be to sheath the rafters with T 111 siding face down then run your perlins on top for the roofing attachment. It's a clean look and can be prepainted for a more finished look. Another advantage is if the HO wants to set up a ceiling fan or lighting. The wiring can be hidden more easily and offer more flexibility in fixture placement. What part of Georgia are you doing this in? I'm in the south Atlanta area.
Is this to be a shed or a gable roof?
If it's a simple shed roof, go with Dave's advice; 2x6 24"OC for span up to whatever local code allows; here that would be 9'-something so it oughta be a bit longer chez vous....
If it's a gabled roof, build yourself some rafter-trusses--take the rafter scantlings from the code tables, then lay 'em out flat on the floor and add a 2x4 or 2x6 ceiling joist/bottom chord; nail it up with 3/8" plywood gusset plates using 2" nails and construction adhesive, then toe-nail it with 3½ inchers as usual. With a 4/12 slope you won't have much ridge height, but you can nail in a couple of diagonal 2x4 webs on each side of center to stabilize the chords. Then just hoist 'em in place and use your purlins or skip sheathing to space 'em out. Saves you the trouble of a ridge beam/board and no bird's mouths, either.
Finally...considering your area is about to get whacked for the third time in as many weeks by major weather, this might be a good time to think about tying down whatever it is you decide to use very well indeed: There ain't nothin' like a big, free-standing roof to catch a bucketful of wind and go tearing off into the countryside....
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
Ditto what Dinosaur said - Gotta keep that thing from heading off to Kansas with Doroty and Toto.
Don't condemn people for their ignorance.
Use it against them.
Excellant responses from everyone. I especially like the idea of sheathing with T-11 board on the rafters/trusses.
Dinosaur I'm thinking home built trusses like you describe would be a good way to go, but I must confess I've never heard of "scantlings." Please enlighten me.
MikeVB