AboutRon Haynes Expertise I can answer questions related to all types of steep slope and low-slope commercial and residential roofing, including asphalt shingles, metal roofing, built-up roofing (tar and gravel), modified bitumen roofing, single ply roof systems, tile, and slate. Questions may relate to design, installation, problem resolution or repair of the roof system.
Experience I have over twenty years experience as a roof consultant dealing with various types of roof systems on commercial, industrial, residential and Government facilities. Experience includes new roof and reroof design, roof repair specification, roof construction, maintenance, failure investigations, performance analysis, inspections, moisture intrusion surveys and studies, and storm damage assessments. I am a registered professional engineer and a Registered Roof Consultant with the Roof Consultants Institute.
Organizations Roof Consultants Institute
Education/Credentials Bachelors Degree in Civil Engineering
Registered Professional Engineer
Registered Roof Consultant, Roof Consultants Institute Certified Infrared Thermographer
Awards and Honors Award Winner, Large Roof Replacement Design Document Competition at the 1999 Roof Consultants Institute International Convention. Dept of Navy Meritorious Civilian Service Award. Armed Forces Civilian Service Medal.
Question i live in louisville ky. 3 over 12 roof. debris...lots of pine needles, leaves, whirly birds gather in valley...new 30 yr gaf timberline roof going up...i prefer a metal valley to make it easier to blow off organic matter....valleys are on attached garage and overhang...about 70 ft of valley total...copper cost:550; aluminum : 415; painted 24 gauge galv steel 225. This is modification post original proposal. From what I understand, galvanized steel... painted..i'm not sure if it is g90 as the foreman did not know of this term..only that it had a warranty for 25 yrs..but he warned that it scratches easily and that when it is trimmed no paint, therefor vulnerable to rust...so aluminum or copper seem to be my choices...copper not that more expensive...am i crazy to have copper valleys in an area where the homes average about 240k?
Answer Bill,
For the cost diff and peace of mind, nothing wrong with choosing the copper. However, you do have a couple of other options/approaches.
First, in any case, be sure to have the valleys lined with peel and stick underlayment prior to setting the metal. This solves a lot of common problems in valley areas and is pretty much standard practice for most contractors these days, but better to ask and be sure than to assume. 70 feet of valley is about $100-$120 in peel and stick underlayment material. It is cheap insurance for a over the life of the roof
Second, you could use painted galvalume metal for the valleys. It has better corrosion resistance than galvanized. Unpainted galvalume looks similar to galvanized. Galvalume in conjunction with the paint finish provides for very good corrosion protection. Actually the unpainted galvalume in a seacoast environment can carry a 20-yr warranty against porforating corrosion. Cost would be very comparable to galvanized metal. You are correct to request G90 galvanized if galvanized is used. G60 is common for shop fab metals and would probably be OK but G30 is common off the shelf at the big box stores and I would not recommend.
Third, the best approach for the metal valley of any type, that also helps to some degree with the cut edge concern, is to set the peel and stick underlayment parallel to the valley. Set the metal valley with 2 to 3 beads of sealant within the end laps and nail the valley metal along the long edges that will be concealed by the shingles. Then, strip in the edge of the metal to cover the nails and cut edge with a 10"-12" strip of the peel and stick material. Overlap the peel and stick strip in standard fashion with whatever underlayment material is being used for the remainder of the roof. Apply the shingles.
