Contractor replacing roof says a weave valley is better than the
metal valleys now installed. How would I know. Need input.
What's best. MN, north facing, 8/12 roof, 30 year shingles.
Thanks

Open valleys are ugly, but woven ones are hard on the
shingle. Most shingle manufacturers will allow either,
but you could check with the manuf. of your specific ones.

If the roofers are competent, it's untimately
an esthetic issue. If they're not, they're perfectly
capably of screwing up either one. So unless there's
some over-riding reason not to, I'd let the roofer do
it his way.

--Goedjn