upright and rafter spacing

[Captain13]

3KillersBees, I was hoping you had. Nothing worse than seeing the roof of your coop 50 feet away from it.

U_Stormcrow, my best friend lives in Greenville, Fl. We get the leftovers from you guys on the tropical storms. Usually 40-60 mph winds, rain and tornados.

 

[U_Stormcrow]

Mine is built post-and-beam style with the posts buried 2 feet down.

Likewise, with 120 or 160# of concrete attached to each post. I won't say it's not going anywhere, but I will say it's not going anywhere easily.

 

[mqoh]

this. Plus, check your roof panel widths. For poly, they commonly are 26” wide - so a 48” gap would be a problem.

And just to confirm, you mean 24 or 48 on center, right? NOT 24 or 48 inches of air between uprights. Just checking cause how you worded it wasn’t clear to me . If you do the 2nd option, you’re gonna run into issues.

Yes on center but thanks for checking

 

[AmeliaBedelia]

But doesn’t the roof attach to the pelum which is attached to your rafters so spacing the rafters would have more to do with strength than fitting material or am I wrong?

I was thinking of poly again, sorry. Lots of people use clear poly roofing to create a greenhouse-type roof over their runs. In which case it attaches straight to the rafters I think? Or are the joints strong enough to “float” between further spaced rafters? Now I need to look more closely at photos…

 

[mqoh]

As long as your roof is parallel to the rafters, and you have adequate purlins/strapping above the rafters you should be okay. The rafters are about strength. The only issue is if your roof can expect any snow load. If you do, then 24" would be better.

Florida ha ha I’d like to see some snow. So how much space between rafters with a galvalume. Or other metal roof?

 

[mqoh]

We did ours as a post and beam structure with posts 8 feet apart and 2x4 uprights to serve as "nailing strips" for the hardware cloth.

Build thread here: https://www.backyardchickens.com/threads/large-open-air-coop-in-central-nc.1443812/

I love your roof and I’m going to do a take on it. I’ll send you a pic when I get done. But how many rafters do I need. Structure is 12 feet with a one foot overhang on each end. Every 2 ft would be 9 is 2 feet overkill or right

 

[3KillerBs]

I love your roof and I’m going to do a take on it. I’ll send you a pic when I get done. But how many rafters do I need. Structure is 12 feet with a one foot overhang on each end. Every 2 ft would be 9 is 2 feet overkill or right

DH isn't sure whether he put them on 16" centers or 24" centers.

@U_Stormcrow, can you advise?

 

[3KillerBs]

Since there is no reason to build it like a people house, it only need be strong enough that you can carefully walk on it occasionally for maintenance, I use 2' on center, purlins spaced approx 24" oc - and I use 5/4 x 6 pt deck boards instead of 1x4 grade 2s for my purlins. Locally, they are cheaper, pressure treated (in case there should be a leak), wider (easier to hit with screws from the top), thicker (more thread grip), and much less likely to have a knot in them which renders it structurally useless.

Did I mention they are often cheaper?

Here are some pictures of one I threw together in a weekend. That's the goat shed. I did something similar with the bunny barn I just extended off the shed.

/edit Thickness of your rafter is based on Span. For my purposes, I'll take a 2x4 to almost 10' unsupported length (meaning a 2x4x12, to allow me 1' of overhang on each end (roughly). I weigh about 165# and of course we have no snow loads. 2x6 for anything of greater span. Whether that's sufficient safety margin for you or not?? I can't answer that. they do make span tables.

Thanks. I knew you'd have the figures handy.

I could guestimate from my build photos, but it's too dark to go out and measure the roof supports.

 

[mqoh]

Here's how to add your general geographical location to your profile.
It's easy to do, and then it's always there!
View attachment 3398807

 

[mqoh]

I did that once. I guess I didn’t do it right