New metal roof

[budepps3760]

Took possession of my father's land and started to put a metal roof on an old building he used for good cabinet shop. Pole barn wad built in late 60's and trees had grown up around it, dropping limbs on top. I clean off 6" of pine straw and found it leaked like a colander which determined my present project.

Decided to strip with 1x4 pressure treated wood and laid the metal roofing panels over the old. With the help of my son-in-law we were able to complete one side..

 

[Deere Dude]

From looking at the first picture it seems it is lacking furring strips from right to lift. You should have had them every two feet so walking on the roof won't bend the metal. Or am I missing something? It does look like a nice shed though. I with mine was that nice.

 

[budepps3760]

The strips are every 3 feet. I placed the strips to overlap the original rafters. The shed is a total of 1800 sq feet. Once I get it roofed again I plan on creating a lean to addition on the where I will take my implements that do not have any electronics or gear box and place them under it. I still have all my father's commercial cabinet equipment which I will use when I build my retirement house on 85 acres next year as well as my tractor and boat inside the main shed.

 

[HCJtractor]

most people run the furring strips perpendicular to the metal. Never seen it done your way, but guess it will work.

 

[budepps3760]

I ran perpendicular strips over the perlins and then vertical strips every 3 feet where the panels overlapped. So for every 12' section I had 3 horizontal strips and 4 vertical strips to screw through.

 

[s219]

Phew, that is not nearly enough screws -- I'd be worried about wind/uplift loads. When I did my roof, the manufacturer had screw spacing specs for each panel/gauge type, and I ended up needing purlins spaced 2' with screws every 8" on the purlins. Of course, if your old roof didn't ever peel off, who am I to talk?

The other thing -- I also used pressure treated for my purlins, but you need to put some sort of barrier between the wood and the metal roof panel, otherwise the pressure treated lumber will accelerate corrosion at all the screw holes. I used a self-adhesive flashing membrane tape for that.

 

[Woody65]

As S219 said, treated lumber in direct contact with metal does not end up well. The more recent additives to the treated wood corrode the metal quite fast.

Also, when furring out the roof for a new metal skin, usually it's done with vertical furring on the ends and horizontal furring every 2' so that you can screw the metal roofing down every 8-12" horizontally depending on your type of metal roofing profile. The way you laid it out is unorthodox but might work for your situation.

Good luck with the project.

 

[KennyG]

It looks like it will work but, if you have to walk the roof, you will have to stay on the vertical members, If you step between them, with the spacing, you will bend the roof.