mobiltec
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Post by mobiltec on Nov 3, 2018 15:07:19 GMT -8
So here's a good one. You would think I would know the answer to this question but really I don't. Something I've never thought about. So here goes. Lend my your thoughts.
When re-installing the original roof does the ambient temperature matter? As we all know aluminum expands and contracts with heat and cold and when installing new metal you want to do it on the hottest day possible so that all the expansion is done. Then when it cools off it all shrinks and either way there is little to know buckling. But what about an old roof? What do you think will happen if it is installed on a cool day?
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ruderunner
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Post by ruderunner on Nov 3, 2018 16:03:47 GMT -8
Buckling when warm. Metal doesn't dry out and age like wood or plastic.
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Post by bigbill on Nov 3, 2018 18:09:42 GMT -8
Larry in my opinion if you are installing the roof in the same position it was, in other words folded and fastened in the same place it was just into new wood or filled screw holes then it won't matter what temp it is. But if you install it on a hot sunny day and stretch it tight and refold it you might get in trouble next winter. Temperature expansion is why aluminum house siding has elongated holes and you never drive the nails down tight, on a trailer roof you don't have that option. I prefer a nice 75 to 80 degree day, but it never seemed to work out that way until I got a shop where I could control the temperature and no sunshine.  |
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Post by vikx on Nov 3, 2018 19:25:30 GMT -8
I've installed original roofs in temps from cool to very warm (75) and never had a problem. If they are molded in the correct shape it seems they fall into place rather well.
I will say that it seemed to matter on our 57 Corvette siding. Plywood walls and original siding, new roof metal, plus front/rear. The street side will show definite buckling when it gets hot or sits in sun. We installed it in about 45 degrees and it fit the wall. I suppose more body screws would take care of it but it's not very noticeable.
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shastatom
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Post by shastatom on Nov 4, 2018 6:00:49 GMT -8
I was just having this problem the other day with my roof. I was installing in about 55 degree weather and it was coming up short. Most of our roofs are seamed and from what I can tell you get something like .0002 movement of an inch or something like that I think per foot. I think you got other issues that cause more problems, like making the walls square, matching height, and other minor differences like a thicker butyl tape.
If you do some google searches on metal expansion you will find the formulas.
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mobiltec
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Post by mobiltec on Nov 4, 2018 8:43:29 GMT -8
Well I suppose there is one way to find out for sure LOL... Thanks for the answers all.
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HOTRODPRIMER
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Post by HOTRODPRIMER on Nov 4, 2018 13:15:31 GMT -8
Let me add another wrinkle to the question, depending on the original manufacturer the aluminum could have been installed at different facility's, in the case of the Shasta's I would think the weather conditions at the California plant would vary greatly with the humid & frigid weather at the Columbia,South Carolina plant.
I am not a metallurgist so my limited knowledge relating to the expansion and contraction relating to aluminum, in this case on the top of the camper, has a memory and will return to it's previous shape. Danny
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mobiltec
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Post by mobiltec on Nov 4, 2018 17:07:24 GMT -8
Let me add another wrinkle to the question, depending on the original manufacturer the aluminum could have been installed at different facility's, in the case of the Shasta's I would think the weather conditions at the California plant would vary greatly with the humid & frigid weather at the Columbia,South Carolina plant. I am not a metallurgist so my limited knowledge relating to the expansion and contraction relating to aluminum, in this case on the top of the camper, has a memory and will return to it's previous shape. Danny Yep. The factories have the buildings set at 80 degrees or higher for metal installation. |
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kirkadie
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Post by kirkadie on Nov 6, 2018 14:11:08 GMT -8
If it's stretched tight on a hot/warm day is there risk of fasteners pulling or distorting the alum if it gets really cold, like here in Ohio? How much movement is there in a wide-swing-temperature environment?
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mobiltec
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Post by mobiltec on Nov 6, 2018 14:59:34 GMT -8
If it's stretched tight on a hot/warm day is there risk of fasteners pulling or distorting the alum if it gets really cold, like here in Ohio? How much movement is there in a wide-swing-temperature environment? I can tell you what I have seen and my experience. I installed the metal on the 66 Super Shasta on very warm days. Over 100 degrees. And then I moved the trailer to northern Nevada and worked on it and watched it over the winter when the temps got down to 8 degrees. Keep in mind I used .030 inch metal from Hemet Valley RV and Siding. I saw no buckling, none of the screws seemed like they were pulling and nothing looked out of place. And the main thing, no leaks. The brakes are supposed to take care of most of the expansion. Same with shrinkage. Now on the 59 Airflyte, which was covered with .025 inch, I put the metal on in winter when the temps were around 50 to 60 degrees. When that trailer was sitting out in the hot sun I saw lots of buckling. So I added exterior screws on both sides and that helped greatly. Now I notice very little buckling when it get's hot. |
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Post by danrhodes on Nov 6, 2018 19:41:19 GMT -8
I installed old siding on an 80 degree day. That summer of 90-100 degree days buckled the siding so much that it pulled the staples out of the seam requiring me to remove in and re-staple along with some very flat head screws.
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oakback
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Post by oakback on Nov 7, 2018 6:47:04 GMT -8
I live in Florida, and I honestly have no idea how hot metal surfaces get in direct sun in the summer, but it's hot. Ambient temps hit triple digits every summer.
I'm still building my trailer, and currently haven't put the siding on yet (or purchased it yet). I was hoping to before year's end. So should I wait until next August to put the siding on? Or what can be done to mitigate this? Or is buckling perfectly fine and just cosmetic and temporary? I'm more concerned about weather proof-ness than looks (but I don't want it to look bad, if possible). It rains a whole lot here, pretty much year-round.
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Post by danrhodes on Nov 7, 2018 8:25:51 GMT -8
I live in Florida, and I honestly have no idea how hot metal surfaces get in direct sun in the summer, but it's hot. Ambient temps hit triple digits every summer. I'm still building my trailer, and currently haven't put the siding on yet (or purchased it yet). I was hoping to before year's end. So should I wait until next August to put the siding on? Or what can be done to mitigate this? Or is buckling perfectly fine and just cosmetic and temporary? I'm more concerned about weather proof-ness than looks (but I don't want it to look bad, if possible). It rains a whole lot here, pretty much year-round. This was a 90 degree day  |
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nccamper
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Post by nccamper on Nov 7, 2018 10:34:32 GMT -8
I installed old siding on an 80 degree day. That summer of 90-100 degree days buckled the siding so much that it pulled the staples out of the seam requiring me to remove in and re-staple along with some very flat head screws. Did it stop buckling with the screws? My campers always had screws. The Forester had them every third brake...so every 12". |
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mobiltec
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Post by mobiltec on Nov 7, 2018 15:21:53 GMT -8
I live in Florida, and I honestly have no idea how hot metal surfaces get in direct sun in the summer, but it's hot. Ambient temps hit triple digits every summer. I'm still building my trailer, and currently haven't put the siding on yet (or purchased it yet). I was hoping to before year's end. So should I wait until next August to put the siding on? Or what can be done to mitigate this? Or is buckling perfectly fine and just cosmetic and temporary? I'm more concerned about weather proof-ness than looks (but I don't want it to look bad, if possible). It rains a whole lot here, pretty much year-round. I would wait until you can have at least an 80 degree day for new metal. I really like the thicker .030 metal. I hung that one during a hot summer and it didn't buckle at all in the heat or in the cold. |
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