Steel roof valley cuts--won't they rust?

Roofing/Construction Questions
#1

I’m considering a steel roof for a current new house construction project. However, there are six valleys on the house. Won’t the steel rust where we cut it to fit the valleys?

Would aluminum be a better choice? Any recommendations for steel/aluminum manufacturers or subcontractors?

Thanks,
Greg

#2

Hello,

You can use a hook strip in the valley. Add an extra inch to your valley cuts and use benders to bend the extra into a hem. Use the hem to lock into the hook strip. We usually have a 6" exposure on each side of the valley to help alleviate the snow build up and let the water run freely.

Keith

#3

We pretty much do it the same way as roofboy described. I’ve seen some roofs where panel is cut at an angle and screwed right down to the valley. I mean this method will work for some time or on some barn, but we would never do that.

We still prefer aluminum over steel, as there is 0% chance that alum will rust. This is not to say that steel is not good enough. I have some pieces of g-90 steel just laying on the ground in mud, under rain/snow, and no signs of rust so far…

#4

Any recs for aluminum manufacturers–probably standing seam?

I figure if I start with a good product company, they can refer me to a good contractor.

Thanks again,

Greg

#5

MFG: Firestone Building Products, Englert…

Here is a metal roofing directory of both manufacturers and contractors: http://www.newenglandmetalroof.com/directory/

Good Luck

#6

the main thing is not to heat up the edge your cutting
it will accelerate the rust process.
use tin snips to make your cuts.
use a galvalume coated steel panel and paint that, or leave it mill finish.

regular home depot metal will rust in a couple a years.

gweedo.

#7

i just did a roof with coated steel valleys,and i find it cleaner to snap a line,mark top and bottom,make your cut then install your shingle.a little slower,but a much cleaner job.

#8

May rust where it is cut or bent because it mars the finish coat. They can use touch up paint that comes with the metal.