metal roofover, on top of 2" foam, or fix ponding?

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peachlizard
Posts: 13
Joined: Sat Aug 01, 2009 12:03 pm
Location: Arkansas

HI, We just joined the forum and ordered the mobile home repair manual online. We want to put the inexpensive metal roof over ours, its a 70's something 12x52' (48' box length) it is our "lake house" so to speak. We are not sure we need to because the original metal roof (no pitch) was covered years ago by a metal roof over (aluminum) with about 2" of styrofoam underneath. We don't know if it leaks yet, although there is evidence of previous leaks. (They could be older than the roof over.) We have only spent 1 week up there and are about to go back for a week Aug 8-14th. The roof has some ponding in places on it. We got up there and cleaned it, and there were about 6 places that hold water anywhere from 1/2" to 1" deep. Some of them were approx. 6" wide by maybe 18" long. So our question is should we do something to patch up the ponding areas and just wait and see? We don't have any idea what to patch these areas with. My search didn't bring anything up on this. We understand the inexpensive metal roof over, but if we don't have to spend money on the whole thing right now, we need to spend it on other things like skirting. Also if we do the whole roof as described in manual, we would have to use something like 5 1/2" screws to go through our extra 2" of foam. Is that feasible?
Any ideas on patching the ponded areas or extra long screws if we must do whole job is very much appreciated. Thanks, the Jackson's in north Arkansas
Old Ticker
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JD
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Joined: Sun Feb 25, 2007 11:57 pm
Location: Fresno, CA
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Hi Old Ticker and welcome to the forum. First of all, I would never recommend putting a 3rd roof over the existing factory roof and second roof. Here in California, that is not code approved without an engineering plan, and even then I doubt they would approve it.

I also would not put anything on top of your panels to try to fix the ponding problem. If you study the roof product, you might see how you can unfasten the roof in the ponding areas, lift the panels slightly and slide sections on 1/2" plywood over the indented area. That is the general idea, but you also may need to modify the plywood or it's placement to not cause too much lift of the panels when you fasten it back down.

Aluminum panel roofs can last many years with only a little maintenance. The insulated roofs I installed over 20 years ago are still great roofs with no problems to the best of my knowledge. There are probably new owners in the homes with the oldest roofs, so they would not know to call me of the contractor I worked for at that time. But I see these roofs in mobile home parks all the time, and they still look great. Sometimes they need new sealants at the vents and ridge caps, but the panels are still in very viable condition. I have never heard of someone removing/replacing the aluminum roof product I install. I have removed steel, rubber sheet and even lesser quality aluminum roof-overs to install my roof product though. Two types of these roof-overs had Lifetime Guarantees. Too bad their businesses didn't have the same guarantee.

If the roof metal is in good condition, I would try to save it rather than replace it.

JMO
JD
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All information and advice given is for entertainment and informational purposes only. The person doing the work is solely responsible to insure that their work complies with their local building code and OSHA safety regulations.
peachlizard
Posts: 13
Joined: Sat Aug 01, 2009 12:03 pm
Location: Arkansas

Yes JD I think you are correct in assuming that this 2nd roof is a company manufactured product similar to what you install. It looks like the ones in the back of our electric coop magazine for mobile homes. It must have been on there awhile because of the ponding. I know it did sit for 2 months at a severe tilt after being repoed. But these puddle places look like they're older because of the dirt built up in them when I "mopped" off the roof. I'm wondering if anyone else is going to chime in and offer any kind of choice as to build up these puddle places, instead of compromising the integrity of the roof by puncturing and cutting into it to place plywood underneath, and still not know if it will lay properly. We have absolutely no experience whatsoever. I do believe the roof is in good shape and water tight except for possibly these places. And they may be water tight for now, but I know standing water always leads to leaks. We also need to reseal around our vents just for preventive maintenance. If we aren't going to use our gas furnace and the gas water heater has already been changed to electric, is there any problem with removing these vents altogether and patching those holes? How should we go about patching those holes? Thanks to everyone for any input you have, EJ
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Greg
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Joined: Wed Feb 28, 2007 8:01 pm
Location: Weedsport, NY

Hi & welcome. If the roof is in good shape I would do as JD recommended, but first I would check the home to make sure it is still level. I am not sure if that would cause your problem but it can't hurt to check it. Greg
"If I can't fix it, I can screw it up so bad no one else can either."
AaronT
Posts: 3
Joined: Tue Jan 06, 2009 3:23 pm
Location: Auberry, CA

I have the exact same problem. I bought this old mobile a few months ago and then lost my job. So right now I can't afford a new roof over. I have several bad ponding areas; some small, some long.
I was able to finally fill in one bad area using many layers of polyester tape & Elasto Seal. But this took forever because you can only do one layer a day or two and then it needs to cure. An area 3/4' deep took me a few weeks to get drainable. one trick I used this winter (here in CA it rains all winter), was to weigh down long strips of polyester tape and wick the water off the roof. It worked great; a strip would drain a pond in a few hours. The biggest problem was that the wind continually blew it off or out of place. Since I had so many bad places, I needed something better. I discovered a commercial polyester spun weed blocker cloth made by Easy Gardner. It is cheaper than the tape and comes in a 40' roll. I laid long sheets of it across my roof and weighed them down. It worked perfectly, but again the wind problem is a hassle. This is strictly a short term fix.
as far as a more "permanent" fix, I had another idea. First let me say I am a complete amateur and this is only an "idea". I have no idea if this would work. The idea was to use those cans of spray, expanding foam to build up the area and then paint over it with Snow Seal. It is light so it wouldn't add weight and it seals an area. It isn't waterproof and has to be painted or the sun will damage it. Also it is brittle and thus can't be walked on. I was going to paint an X on it to warn me to avoid it. But the small section i tried this on did not go well. I used the Big Gap kind and it expanded too much. It does not level out; it instead develops large bulges and leaves holes. You can cut down the bulges but this is a hassle and you can fill in the holes with Snow Seal. I ended up with a mound on my roof. It certainly sheds water but looks really weird. Also, I don't know how long this will last. I would think, since it is sealed, it should last for years. If I could find a foam that flowed more and leveled out, it would work much better. I thought later maybe I should have tried to smooth it out on application, but this stuff is very sticky & messy.
Anyway, I am just throwing this unproven, wacky idea out there. Any feed back from the pros would be appreciated.
Aaron T
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JD
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Aaron - I like the polyester wicking cloth idea as an emergency or temp fix. Kind of like siphoning the water out. Not so good for freezing temps, but it could be removed when freezing and replaced when thawing. Fine line there in application, but the theory is cool.

JD
☯JD♫
Today is PERFECT!

All information and advice given is for entertainment and informational purposes only. The person doing the work is solely responsible to insure that their work complies with their local building code and OSHA safety regulations.
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