16x16 Cabin Roofing ?'s

[Crappie Slayer]

Well i have not posted on here in a little while.  I have been a little busy doing a complete build by myself.. I have came to the point of doing the roof on my 16x16 cabin in Oklahoma.

I have all the gambrel barn style rafters hung and in place,,, was a chore all alone,, and the ends framed in,, but it is all still really shaky,,, does the decking stop all that ,, or do I need to run stringers (maybe 2x4's) down the length of the building every couple of feet.

I have been told by my grandfather that we can put a metal roof right onto the rafters...  I have always seen the metal placed on top of the sheating.... ok that would be question number 2.. it is a 16x16 cabin with a gambrel style (barn type) roof.. rafters on 2ft centers.  Can I use 7/16 osb for roof decking and metal on that and be ok.

I am kinda at a stand still until I get some good advice on this.. and of couse working alone on a little project like this has been an adventure to say the least. 

I would like to get it dried in before the fall rains get here... but I am thankfull for all the nice 75 degree days we have been having here is NE Oklahoma, of course it is like an hour and a half to my build site from Tulsa.  That was alot of questions kinda bouncing all over the place about the roof... but that is one thing that I have never done is a roof.  Any and all comments are greatly appreciated.. thank you.

Chris

[Redoverfarm]

Well i have not posted on here in a little while.  I have been a little busy doing a complete build by myself.. I have came to the point of doing the roof on my 16x16 cabin in Oklahoma.

I have all the gambrel barn style rafters hung and in place,,, was a chore all alone,, and the ends framed in,, but it is all still really shaky,,, does the decking stop all that ,, or do I need to run stringers (maybe 2x4's) down the length of the building every couple of feet.

Generally you would attach either temporary purlins (2X material) to get the rafters plumb until you attach the sheeting.  Some will attach these on the underneath side not to interfer with the sheeting installation.

I have been told by my grandfather that we can put a metal roof right onto the rafters...  I have always seen the metal placed on top of the sheating.... ok that would be question number 2.. it is a 16x16 cabin with a gambrel style (barn type) roof.. rafters on 2ft centers.  Can I use 7/16 osb for roof decking and metal on that and be ok.

You can place the metal on top of the rafters after you secured "purlins" running perpendicular to your rafters but not directly to the rafters.  As for sheeting I would go no less than 5/8" on the roof sheeting.

I am kinda at a stand still until I get some good advice on this.. and of couse working alone on a little project like this has been an adventure to say the least.  

I would like to get it dried in before the fall rains get here... but I am thankfull for all the nice 75 degree days we have been having here is NE Oklahoma, of course it is like an hour and a half to my build site from Tulsa.  That was alot of questions kinda bouncing all over the place about the roof... but that is one thing that I have never done is a roof.  Any and all comments are greatly appreciated.. thank you.

Chris

You have several factors to take into consideration.  Ventilation, insect control and insulation.  If you just use purlins then understand that the metal will sweat.  That could effect your insulation.   In addition with just purlins you have no way to control insects.  If it were mine I would sheet, cover with felt paper or synthetic underlayment and attach the metal.  Others have even placed purlins on the sheeting and then attached the metal.

[nysono]

Agree with the above, use 2x for lateral and diagonal bracing on rafters, sheet with 5/8 osb then underlayment and steel.  Lateral and diagnoal bracing was code requirement for me and its easier to do before sheeting is on.

[CjAl]

Last year my wifes uncle had a new metal roof put on. Its metal with just stringers across the rafters. This house has huge porches all around and this year there is so many wasps living in the roof you can not go outside on the porch. And now they are getting in the house.  I would suggest sheething the roof as tightly as possible, felt then putting themetal roofing on, and use all the proper trim

metal directly on the rafter/ stringers is ok for non insulated pole sheds and thats about it

[MountainDon]

Much of the metal panel roofing sold is NOT listed as suitable for use as a structural panel. Fastening the metal panels to the rafters or purlins run horizontally requires a structural panel. OSB makes for a fine structural panel; put the metal over that with roofing paper or other weather resistant barrier in between the OSB and metal.