attaching corrugated roofing

[kevindean]

Be sure you put the screws on the high side of the curve and use rubber wasers attached to 1x3s

 

[j.luetkemeyer]

Putting 1x over the OSB is just an added expense in my opinion. I've done a lot of building with metal and never done that. I just make sure the screws go through the OSB and into a stud. You could paint the OSB first; however, I have never worried about that. The only issue would be humidity. As long as the wood can "breathe" it usually stays dry enough to not rot. One suggestion I do have is a radiant barrier if the building you are putting the metal on is in direct sunlight. This would only be helpful if you need to keep the building cooler in the summer.

 

[zachslc]

What is this radiant barrier? The roof will be west-facing and it does get hot here. Frankly, I had not given it much thought. Can you expound on your recommendation?

Thanks.

 

[Zahboo]

Look by the corrugated stuff, there should be wavy wood peices. These can be used as braces and closing gaps. When I used these and nails with the waterproof washers, it's been waterproof for 2 years so far.

 

[azelgin]

Screws should be in the valley of the corrugations, NOT on the ridges. Attaching on the ridges deforms the material and will eventually cause problems. The only time you screw throught the ridges is when using stitch screws to attach adjoining panels and the screws should be short enough to NOT reach the supporting structure.

http://www.mcelroymetal.com/elements/files/MM206Rev3-13-08.pdf

 

[cruizer]

I would not use OSB. I would put the trusses up, use 1x2 furrings strips running sid4e to side on the trusses, the put your corrugated tin u and down the furring strips, Use self tapping screws with the rubber washer in the valley not the peak of the corrugations.

 

[jvls1942]

I was a contractor for 35 plus years.

do not use nails.

do use screws with the neprene washers made for the roofing.

do put the screws on the rib,, not in he valley.. stop screwing just as the washer starts to squash. back the screw out a bit if you have gone too far.. when water is running down the roof, where does it run? in the valley...

do screw through the osb into the rafters... I assume you already have osb nailed on..

I can tell you this, though.. you are going to have very few ribs line up with your rafters..

I would nail at least 1x3 or 1x2 strips no less than every 2 feet apart for fastening screws..

I also would not plug the channels with wavey wood or foam.. you want the air to move freely between the roof and metal..

did I miss anything??

 

[fargosmom]

I'm also going to use corrugated roofing and I'd already planned on leaving the gaps under the peaks open for ventilation . . . but does this allow enough space for rodents to enter? I was thinking of covering the openings with hardware cloth but I'm not sure of the best method - or if there's a better way. I know that where our coop is positioned we'll have some mice and rats, and I've made sure everywhere else to try to keep them out, but this last opening has me stumped right now.

 

[azelgin]

Quote:
I guess we've both been at this for the same number of years.

Fabrel, McElroy, ABC, Champion, Bruce&Dana and all the other manufactures I've worked with all say the same thing: screw fasteners go in the valleys of corrugated panels. I try to follow the instructions of the people suppling the product. Makes it easier to obtain warranty coverage later on. Corrugated panels should also not be used on slopes less than 2/12.

I agree on not using nails. They eventually work loose and leak. #30 felt over solid sheathing, or, some type of vapor barrior/insulation when over open framing should be considered too, to prevent condensation on the underside of the roofing metal.

Leaving the ends of the metal corrugations open for ventilation will help keep your roof sheathing/felt dry.

 

[azelgin]

Quote:
If, you're putting your metal over solid sheathing, it's common to leave a space at the top of the roof sheathing, covered with hardware cloth, to ventilate an attic. I've never had a problem with critters between the metal and the roof deck. It's not the most comfortable place to set up housekeeping.

If, you are going to put your metal over open framing (no roof sheathing) then it would still work to leave a small space at the top for ventilation. Plugging off the bottom would not matter.