We have invited Charlie to share his expertise and answer industry questions on metal recovers. Known for his great teaching and mentoring abilities, we asked if he could share his expertise, helping the industry really understand the opportunities with recover systems utilizing metal roofing. Are you currently doing metal recovers or are you interested? Let us know. Also be sure to listen to our podcast with Charlie Smith. Roofing Road Trips with Heidi Podcast
Tell me about any recover jobs you are working on or if you are interested in getting into recover work.
Charlie, David asked the following question:
Hi, I hope you can answer my question about installing polyiso on a mobile home under a metal roof. I have some older mobile homes and want to install metal roofs. I have found some used Firestone polyiso 1.5" thick. My first thought was to attach 2x4 strips length of mobile home and install the 1.5" polyiso between the 2x4 strips. Using 2x4 strips screwed to existing mobile home roof and then the sheet metal screwed down to the 2x4s. BUT when I Googled, I found a guy that laid down the polyiso and then striped out on top of polyiso with 1x4s. He used 4" screws and screwed all the way through the 1x4x, polyiso, and in to the sheathing. Should it be done this way? My worry is that over time the polyiso will deteriorate and leave a gap, causing the roof to be lose? Or is this the best way to do it. I have some mobile homes with flat peak roofs, and some with the old style low slope curved roof. Any suggestions would be hugely appreciated. Thanks, David
David, i would not do the 1 x 4 on top of the iso. i do not see any purpose in it. IF you want to run 2 x 4 accross and attach to the framing then attach your new roof to them, it will probably be ok. I assume you are installing a screw down roof, is that correct?
I would just be careful installing the 2 by fours in try not to crunch the ribs too much on your existing roof panel.
also I would not use 29 gauge on anything.
David I would use 26 gauge if it was me but 29 gauge may work fine for you. I know we sell a lot of 29 gauge here at McElroy, but that stuff is mostly installed on pole barns with wood purlins spaced 2' o.c. How far apart are you planning to space your 2 x 4's? Also, where are you located?
i am in Texas. i would say try the 29 gauge on one and see how you like it. i am thinking you will need a ridge cap on the first one and the second one it should bend over with 29 gauge. Try it on a small area to see if it works. I think you are on the right course.
I will assume the 26 ga will bend. It is grade 80 material so it will be stiff, but should bend. Like i said before, try a little to make sure you get what you want before you go all in. start in the middle and work your way down. i would say two guys is good.
Do you have any commercial metal over metal recover opportunities you are working on? I’d welcome the opportunity to discuss options and I may be able to keep you out of the ditch!
Have you ever installed a metal-over-metal recover? How did it go?