treated wood and galvanized roof

jim smith
7/22/2011
I've just put a plain, galvanized (shiny, no paint or color) metal roof on my home addition. As my house is two stories, the wall above the roof will need the siding replaced as I tore it off for construction. I was thinking of using treated pine and staining it for the siding. My question is will any water that runs off this siding and onto my roof cause the roof to rust or discolor?
Todd Miller
Isaiah Industries, Inc.
7/22/2011
The chemicals in treated lumber can be corrosive and damaging. If you have any way of sealing them beyond just the stain, that would be good.
jim smith
7/22/2011
Same thing with cedar lap siding?
Todd Miller
Isaiah Industries, Inc.
7/22/2011
If it is natural lumber without chemical treatment it should be okay.
jim smith
7/22/2011
Thank you
Eric Novotny
An informed customer is the Best Customer!
7/22/2011
I have seen plenty of flashing metals pulled off PT lumber and the amount of deterioration is significant. Be careful and use compatible components.
Guest User
9/18/2011
I am putting metal roofing over asphalt shingles. Should I put the metal roof directly on the asphalt shingles or can I put #2 pine boards between the two? Thanks
Todd Miller
Isaiah Industries, Inc.
9/18/2011
First of all, I always suggest underlayment over the old shingles regardless. From there, some products can be installed on battens or direct to deck. Some must be installed on battens. And yet some other products must be installed on solid decking. The best choice is to determine the product you want to use and then ensure it is installed according to specifications.
Eric Novotny
An informed customer is the Best Customer!
9/19/2011
+1 Underlayment, slip layer, is a must and is cheap insurance for a metal roof.
Guest User
1/10/2012
I am looking at hiring a contractor to install a metal roof over an older asphalt roof. The guy I have been talking to tells me that there is “NO” special training required to install a metal roof and the warranty will not be effected. Is this true? I posed back to him that means I can walk down the street and hire the 7th person I see that is wearing blue socks and have a stranger install my $18,000 roof and the manufactures warranty will still be valid for the next 50 years. What training is required to install a metal roof to keep the manufactures warranty valid?
Eric Novotny
An informed customer is the Best Customer!
1/12/2012
I would be very interested to see some of his/her sample work with that sort of proclamation Stacy. Metal might not require "special" training if you have learned OJT (on the job) but it is an entirely different set of skills than laying asphalt.
Guest User
5/4/2016
I am tearing off my old metal roof and the one by sixes we bought three quarter inch treated board plywood can I put ice and water Shield over that plywood or felt screwing the middle deck right to the plywood thank you very much
Guest User
3/7/2017
Heard treated wood messes up metal roofing, so what type of 1x4 do I need to get?
Todd Miller
Isaiah Industries, Inc.
3/7/2017
Nikos, it sounds like you're thinking of installing over battens. Please realize that not all metal roofs can be installed over battens and only a very few MUST go over battens. You are correct on the treated lumber thing. if you go with battens you will need to go with raw untreated lumber or painted lumber.
Guest User
3/7/2017
Todd wouldn't an untreated board rott quick with the weather?
Todd Miller
Isaiah Industries, Inc.
3/7/2017
If the roof is properly installed, they will not be exposed to the weather. Many metal roofs can install direct to deck with no battens. Here is a short video on this subject that may interest you. https://www.youtube.com/watch?v=pEWcwNg29Ag&index=31&list=PLMw9xVe_yEaVt4yv1i4LoDTlNKNd6boRd
JERRY KIRK
5/8/2017
Am I correct in assuming that you should NOT use treated wood for furring strips underneath a metal roof ? I am installing standing seam over an old shingled roof which is not flat in some areas due to warping of the old ( sawmill ) rough lumber used in the original construction . The roof is structurally sound otherwise . Should I also use a plastic barrier before installing the furring ? Thanks , Jerry
Todd Miller
Isaiah Industries, Inc.
5/8/2017
I would install an appropriate, manufacturer-approved underlayment before the metal is installed, whether or not you use battens. Most manufacturers have approved the synthetic underlayments that are widely available now. If you use battens to try to help level things out, make sure that the metal roof panels you are installing are approved for use over battens. Battens need to be untreated lumber -- not treated lumber.
Guest User
5/24/2017
if I have a metal roof and I want to install another metal roof on top of the original metal roof. We were going to use like a 1x4 to attach to original roof. can I use untreated timber to attach the new metal roof
Todd Miller
Isaiah Industries, Inc.
5/29/2017
You should be able to do that. Make sure that the new roof is approved for installation over battens like that.

If you would like to reply to this thread, please log in. If you do not have an Ask the Experts forum user account, create one here.

Find a Contractor

Get Started Today

Take the first step to increasing the value of your home with a great looking, durable, fire resistant and energy efficient metal roof. Browse our list of qualified MRA Member Roofing Contractors in your area for a free consultation and estimate.