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TOPIC: Roofing over existing roof

mobilehome-metal roof

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I have a mobile home that's 20 years old and was wondering if I could put metal roofing over the existing metal roof and what I would need to do so.
Guest User

1/24/2005
They generally have a very low slope and attention to detail on a drip edge needs to be paid. Depending on the arc or slope of the roof, you may be able to use a single sheet of a low profile through fastened panel. Strap the roof horizontal not too far apart , install a drip edge to cover the strapping. The sheets should be set in butyl tape along the drip edge and on the joints to seal against water back up.
Allan Reid
Dura-Loc Roofing Systems, Inc.

1/25/2005
what do u mean by strapping the roof?I have a double wide trailer and want to put on a metal roof over existing shingles.I have sky lights and vents on the roof also,how do I go about making them water tight?
Jim Monahan

5/29/2005
Al's reference to strapping is about installing the metal roofing on horizontal lathe instead of direct over the existing. This applies especially with some of the older manufactured homes. It sounds like your roof has plywood decking and, presumably, ventilation beneath it. That creates a better situation. You need to know the pitch of your roof ... and then look for metal roofs that can be used on that pitch. Then contact the roofing manufacturers for their prescribed installation details ... probably underlayment, eave starter, gable trim, roof panels, and ridge cap. Also make the inquiries about skylight and vent flashing. All of this depends upon what profile of metal roof you select. Through-fastened, standing seam, or shingle style -- they all have different flashing methods. You also may wish to contact the manufacturer of your home and ask what they suggest. If you like, email dircet to me at [email protected] ... I have a guide to metal roofing I can email to you in return.
Todd Miller
Isaiah Industries, Inc.

5/29/2005
I HAVE A 15 YR OLD DOUBLE WIDE THAT I AM PUTTING A METAL ROOF ON AND I AM USING 2X4 PURLINS THAT IA WHAT I USED ON MY GARAGE. I WAS GOING TO USE 2 AND A HALF INCH SCREWS,BUT I THINK I WILL USE 3 INCH ON THE PURLINS.WHAT DO YOU THINK? AND ALSO I GUUESS I NEED TO USE TARPAPER UNDER THE METAL?I DIDNT THINK I NEEDED TO SINCE THERE IS ALREADY SHINGLES THERE, THEY SHOULD DO THE SAME THING,PLUS THAT WOULD BE EVEN MORE WEIGHT,YES?AND DO I NEED TO USE SOME KIND OF DRIP EDGE ON THE FIRST PURLIN BECAUSE I AM GOING TO HAVE AN INCH OVERHANG SO I WONT OVERSHOOT MY GUTTERS.
Guest User

8/24/2005
Mike, yes, you should have a drip edge on the eave edge. As far as the screw length,I think that is a function of more than just the metal roof but 3" might be best. As far as underlayment, I would suggest underlayment over the existing shingles. Actually, I am a little curious why you're using purlins. If you wnat added ventilation (which is a good idea), you would really need to do vertical battens followed by horizontal battens. I would suggest checking with the manufacturer of the metal roofing for their advice on these points as well.
Todd Miller
Isaiah Industries, Inc.

8/25/2005
THANKS FOR THE INFO- I DECIDED TO USE 1X3 FURING STRIPS INSTEAD OF 2X4 FOR PURLINS BY ADVICE FROM THE MANUFACTURER. SO WHAT YOU ARE SAYING IS THAT THE TARPAPER NEEDS TO GO UNDER THE STRIPS OF WOOD OR ON TOP? AND I ALSO NEED A DRIP EDGE ON MY STARTING OF WOOD. I GUESS IT WILL HAVE TO BE A SHORT ONE SO I DONT HAVE TO REMOVE MY NICE GUTTERS.I GUESS THIS IS NEEDED SO THE WATER WONT BACK UP UNDER THE METAL AND ROT THE WOOD EVENTUALLY. I APPRECIATE ALL YOUR HELP IN THIS MATTER.
Guest User

8/26/2005
Yes, there should be a drip edge. I really think you should get the roofing manufacturer's take on the underlayment question. Personally, I would put underlayment over the existing shingles, beneath the battens.
Todd Miller
Isaiah Industries, Inc.

8/26/2005
TODD, THANKS VERY MUCH FOR YOUR HELP AND WISDOM,IT MAKES IT A SMOOTHER OPERATION FOR ME.I GLAD THIS SITE IS HERE AND FOR YOUR HELP AND THANKS AGAIN FOR EVERYTHING.
Guest User

8/26/2005
Sure.
Todd Miller
Isaiah Industries, Inc.

8/26/2005
I am considering puting a metal roof on an 18 year old, single wide 16x82 Lancer mobile home. The roof which is currently shingled and is starting to curl up in the center, doesn't have much of a slope. It has a very high ceiling-(10 feet at least) and no extra support beams plus very few actual rooms-it is a very open style. I am concerned about the weight of a metal roof and whether the structure of my mobile home can support one. Apparently Lancer was made by Champion and I have been unable to contact anyone at Champion who can give me any assistance about my particular model. Thank you for any assistance you can give me.
Guest User

9/14/2005
I would sure keep after Champion for their input. However, metal roofing is much lower weight than standard shingles. It would be important to find a metal roof that is appropriate for your low roof pitch but, once you do that, if you remove the existing shingles and install metal, you will have a roof system that is less than half the weight of the original roof.
Todd Miller
Isaiah Industries, Inc.

9/14/2005
what kind of vent covers must i use on my new metal roof.
Guest User

2/2/2006
I am not sure exactly what you are referring to but the manufacturer of the roofing should provide instructions which will include information on what sort of vents, pipe flashings, and other accessories are best with their roof.
Todd Miller
Isaiah Industries, Inc.

2/2/2006
could you email the roofing info. on how to install a metal roof over an existing single wide mobile home roof. My email is [email protected] We will be starting on this this weekend and need some final tips! Thanks so much if you could send any instructions..
Guest User

4/12/2006
I am sorry we cannot help you with this as this is strictly a function of the type of metal roofing you install. Make sure the products you choose is appropriate for the roof pitch and construction you have. Obtain complete instructions from the manufacturer of the roofing you use.
Todd Miller
Isaiah Industries, Inc.

4/13/2006
what is the cost of metal compared to shingles. What is the life span of metal (30yrs) is what I have been told. On this site I read of utility savings what are you looking at, as a gess. By using the larges pirnils recomended will this increass the saving of utilitys?
Guest User

4/17/2006
Shingles have various grades of material that offer differing life spans and performance. The same is true with metal roofing. Longevity is related to the quality of the substrate and finish. The substrate should be a G90 galvanized or AZ50 Galvalume for coated material and the best finisheds are a PVDF and SMP in the paints along with the granulars. The better the product, the more expensive. The purlins for vertical rib sheet goods should be what the manufacturer recommends but they should be stoof off the roof deck with a minimum 1" spacer board so that there is vertical air flow from the eaves to the ridge. This will reduce heat transfer. Choose a light colour and look for energy star rated products that rate the reflectivity to get further savings.
Allan Reid
Dura-Loc Roofing Systems, Inc.

4/18/2006
My single wide Redman manufactured home is 14 ft wide and has an aluminum roof that is pitched with vaulted ceilings inside. I would like to install a metal roof. What underframing do I need to put up before I install the metal.
Guest User

6/28/2006
you can use regular corrugated metal roofing.al you have to do is install a grid of 1x3's every 18" or so from the gutter to the ridge cap.screwing a single screw into each area it intersects to the original roof rafters. standard ridge cap will work if your original roof is pitched.Im a Metal Roofing Fabricator. I have been re-roofing existing mobile home roofs for about 11yrs. I have a system, I use, that is less then 1lb. per sq. ft. It is ventilated and also strenghthens the existing roof structure. There are 13 beautiful colors to choose from. Putting this system on will assure the end to any and all roofing issues.(814)224-4268 or email: [email protected] thanks.
Guest User

6/28/2006