New Metal Roof for DoubleWide Home - Insulation

Stephanie McGuire
2/15/2017
I am getting quotes to replace the roof on my doublewide home with a metal roof. I have requested the shingles be removed for several reasons....I don't want the additional weight on the roof, I suspect there may be some moisture at the ridge due to some spots of mildew showing on the inside wall where the roof is joined, also I want to add some insulation. Since the home is a doublewide with vaulted ceiling, I can't add insulation inside an attic space. I want to add some R-value along with the new roof while I can. I had a contractor quote adding 3/4" foam insulation between 1x4 strips to which he would attach the metal roofing. When I asked if he was quoting me a standing seam roof where the fasteners/screws would be concealed he said no. He built me a metal barn a few years ago and referenced that roof construction. He said standing seam metal is designed to go over a solid surface and not a roof stripped by 1x4 boards. He said he could quote the standing seam roof but would need to eliminate the foam insulation and strips and just add new paper before installing the metal. I want to do this right but I'm not sure what is the best approach. I like the idea of the standing seam clean look and the fasteners being covered (no exposed screw holes). But I want to add some insulation since this is the only way I know how I can do that with a doublewide roof like mine. Any advice would be greatly appreciated.
Todd Miller
Classic Products, Inc.
2/15/2017
I think that the foam is a good idea. Better yet, I'd love to see some ventilation added to the roof system. There are, by the way, true clip fastened standing seams that can be installed over battens rather have to go over solid decking.
Guest User
2/15/2017
He will be installing a ridge vent along the length of the roof. Do you feel that will be sufficient ventilation? Can you recommend a standing seam product that can be installed over battens? Am I correct that the standing seams where there are no exposed screws is a better option?He gets his materials from one local supplier...He must not be familiar with other products. Thanks again for your response.
Todd Miller
Classic Products, Inc.
2/16/2017
Thanks. Ventilation requires intake and exhaust. The ridge vent would provide good exhaust but you would still need to make sure you're feeding adequate air to it from intake vents at the bottom of the roof. Here is a page with some good info on ventilation: https://www.classicmetalroofingsystems.com/about-metal-roofing/ventilation/ I do prefer concealed fastened products whenever possible and, yes, standing seam would accomplish that. You might make connections with ATAS International and Union Corrugating as possible suppliers not terribly far from you.
Info @windowsonwashington.net
An informed customer is our best customer.
2/16/2017
+1 to Todd's information. Great link by the way. Ventilation only works if you have sufficient intake to balance the exhaust.
Stephanie McGuire
3/23/2017
My contractor suggested leaving the holes where he will remove the current roof vents for added ventilation. Also, he is going to come out and look at my soffits and give his opinion on incoming air. He had originally told me the standing seam product (local dealer Max Kendall Lumber Co.) had to be installed directly to a solid surface and he did not think he could install it on purlins to allow for the insulation. He spoke with a representative at Max Kendall and they told him the standing seam should be fine if he runs the purlins closer together. I like that this contractor is researching how to best resolve my problems and give me the best product/install I can afford. What is your opinion of this information?
Todd Miller
Classic Products, Inc.
3/23/2017
Thanks Stephanie, I am not sure but I think what he wants to do is remove the vents but leave the holes? I really don't suggest that. It is a safety hazard but also is not a way to ventilate things. Good ventilation requires intake and exhaust ... think of it as trying to continually bathe the entire underside of the roof deck with fresh air. Many contractors unfortunately do not understand the importance of this. If he does install a ridge vent then that acts as the exhaust. The eave vents act as intake. Any other holes or vents will just disrupt the air flow that you want to have.
Guest User
7/27/2017
I was given the option of installing a metal roof on the doublewide trailer we are going to buy. Is this worth the $7000 upgrade fee. And ive been told you have to replace the screws about every 7 yrs because the rubber will dry rot.
Todd Miller
Classic Products, Inc.
7/28/2017
There are many re-roof systems designed for metal roofs that do not have exposed fasteners. Most metal roof customers are folks who intend to stay in their home for 15+ years, to recoup the investment. Obviously, I have no exact details of your home or the exact type of metal roof that is proposed, but it does not sound like a bad option. I would make sure that you understand exactly what type of product is being installed, and confirm that it is appropriate and approved by its manufacturer for installation on your roof. Many manufactured homes have low pitch roofs and not all metal roofs can be used on them. Be sure that you understand what warranties you will receive on both the product and the installation, and who they come from. Thanks for considering metal.

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