can you fasten corrugated plastic roofing in the valleys?

[fiddlebanshee]

In stead of the hills? I bought roofing fasteners that are likely too short to go through the hills. Do I need to go back and exchange? (I'm trying to avoid a trip to the hardware store). What is the reason that you need to fasten them through the hills?

The roofing I got was suntuf (I think) clear corrugated polycarbonate. The roof surface I'm covering is 4x5 ft.

Opinions appreciated. Hope to finish this by today so if someone could reply before dark EST that'd be great. Chicks are arriving Tuesday so hope that they will have a roof over their heads.

 

[fillmore]

im not familiar with requirements for fastening through the highpoint of the corrugated profile. maybe the material is more volatile in extreme conditions and expansion/contraction causes oil canning or cracking. this is 20sf of chicken coop roof, not high end construction...fasten through the shallow part of the profile without over-tightening and keep an eye on it; it will probably be fine for your purpose.

 

[PorkChop]

The down side of fastening through the valley is water has a better chance of leaking, where as fastening through the high point not much chance of water collecting there. I've done both, my coop is fastened through the high point and my run is fastened through the valley. I used the nails with the rubber washer on the coop and the screws with the rubber washer on the run. If you bought regular nails or screws without the rubber washer you might want to run back to the store, but both ways worked for me without any leaks. Good luck.

 

[fillmore]

yes, i would amend my previous post to include the assumption that youre using the self-sealing fasteners. if not, be sure to use exterior sealant on all fastener penetrations.

 

[fiddlebanshee]

Thanks all for responding. Yes, I got the screws with the washers incorporated. I just got the 1" in stead of the 2". What was I thinking?

Well I fastened them in the valleys and we'll see what happens. The roof is for the most part under a roofed run, so I don't think I'll have any leakage problems from this.

I may have to shield off the west side between the rafters to prevent windblown rain coming in. We'll see how much of a problem this is. Guess first storm will tell me.