mandjmckinney Posted July 29, 2013 Share Posted July 29, 2013 The roof around my air conditioner on my 91 warrior sags about three quarters of an inch. My idea is to use aluminum U channel from side to side on the top in front of and behind the air conditioner. Inside I will use a 1X4 on the ceiling right underneath the u channel. Using a bottle jack inside I'll take the sag out of the roof and then drill and bolt while sealing it to prevent leaks around the bolts. I would also replace the seal around the AC opening. Where we live in Southeast Texas would only get around 60 to 80 inches of rain a year so the sag is kind of a big deal here. Any help or suggestions would be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
WME Posted July 29, 2013 Share Posted July 29, 2013 See if you can give the u channel a bit of a curve, better drainage that way. Make sure the u channel goes to the edge, that's the only support. Quote Link to comment Share on other sites More sharing options...
mandjmckinney Posted July 29, 2013 Author Share Posted July 29, 2013 I would think that if the U was flexibe enough to curve one way then over time it would eventually curve the other way. Perhaps I could achieve a curve with a series of graduated spacers of ever-increasing size under the U channel as I got closer to the outward edge. Quote Link to comment Share on other sites More sharing options...
WME Posted July 29, 2013 Share Posted July 29, 2013 Put 2x4 under each end and jump in the middle. You can form anything with enough force Quote Link to comment Share on other sites More sharing options...
mandjmckinney Posted July 29, 2013 Author Share Posted July 29, 2013 It seems to me that the bend would weaken the aluminum and make it more likely to bend in the other direction with the weight of the air conditioner over time, especially when you take into consideration the gravity and the force of bumps on the road. Quote Link to comment Share on other sites More sharing options...
WME Posted July 30, 2013 Share Posted July 30, 2013 Flat or curved they will bend the same. With a curved support you can make much stronger with a simple truss. A load applied to a curved support will try to flatten it and make it longer. On a toyhouse you would place the load on the wall and they would try to spread apart. But by placing the support over a exhisting roof beam and tying them togather you prevent the curved support from flatening out by spreading. WME Quote Link to comment Share on other sites More sharing options...
mandjmckinney Posted July 30, 2013 Author Share Posted July 30, 2013 We are supposed to have a week of no rain so I hope to get a better idea of what I am dealing with. I have a place close by that stocks the aluminum so I can pick it up pretty easily. I already have a new seal. About how much does the roof AC weigh? Quote Link to comment Share on other sites More sharing options...
WME Posted July 30, 2013 Share Posted July 30, 2013 The roof ACs weigh in the range of 100lbs, so its normally a 2 person job to wrestle one around. P.S. When I'm talking about a curved support I mean about 1" or so, just enough to give water some direction to drain off what used to be a flat roof. Quote Link to comment Share on other sites More sharing options...
rusticandy Posted July 31, 2013 Share Posted July 31, 2013 I just completed this repair! I went to the local metal recycling place and bought 2 1" by 2" by 8 box aluminum bars for the price of the weight of aluminum. (under $15) I presprung them by jumping up and down on them with my legs in two places, while the bars were on 4x4s at either end. They had a 3" defelction across thier cut span of 7 feet. I used a thin flat bar on the roof inside as a "washer" strip to spread the bolting compression surface and bolted through the roof from the underside with 5 sheet metal bolts on each bar. The roof is now dead level where I placed the bars. I ran the bars all the way to the edge. I also ran bars perpedicular between the bars to completely box the roof AC vent hole, The AC is now 1 inch off of the roof level as it is up on the bars. I butyl tape underneath the bars too, and caulked sealed everything. I powersprayed it and nothing leaked If I had it to do over again, I would have put another bar at the back of my AC unit too, There is still deflection there. Heres the crudest of scematics: side-----------------bar-------------------side b b a AC Unit a r r side-----------------bar--------------------side Good luck! Its doable!! Quote Link to comment Share on other sites More sharing options...
mandjmckinney Posted August 1, 2013 Author Share Posted August 1, 2013 I have removed the cover from the air conditioner. I've taken out the three bolts that were holding in the unit that pulls it from the bottom. I have cut away all of the caulk the previous owner applied around the edge of the air conditioner to try to seal it. Evidently at some point I thought it was necessary to caulk the Coleman cover to the metal. So I don't seem to be able to touch the plastic cover of the air conditioner. I'm thinking I can lift it from the inside and just push the whole unit out on to the 2x4s on the roof. I'm giving it a couple of tries but it doesn't seem to want to budge. I'm guessing there's more caulk somewhere else that I haven't seen it. Any input at this point would be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
mandjmckinney Posted August 1, 2013 Author Share Posted August 1, 2013 I have removed the cover from the air conditioner. I've taken out the three bolts that were holding in the unit that pulls it from the bottom. I have cut away all of the caulk the previous owner applied around the edge of the air conditioner to try to seal it. Evidently at some point I thought it was necessary to caulk the Coleman cover to the metal. So I don't seem to be able to touch the plastic cover of the air conditioner. I'm thinking I can lift it from the inside and just push the whole unit out on to the 2x4s on the roof. I'm giving it a couple of tries but it doesn't seem to want to budge. I'm guessing there's more caulk somewhere else that I haven't seen it. Any input at this point would be greatly appreciated. Right now I'm thinking about a bottle jack and a four by four just putting a board underneath the bottle jack to displace the weight and push on it until it separates. Quote Link to comment Share on other sites More sharing options...
mandjmckinney Posted August 2, 2013 Author Share Posted August 2, 2013 Took a clue from Rustcandy and got me some recycled square aluminum tubing. I've taken it to a shop to have them weld it into a square the size of my opening. I also left enough extra for a bar to support the back of the air conditioning. Since my dip was only about 3/4 of an inch and there was no delamination in my roof I decided not to go to drastic. I figured I could just put a gasket on this just like it was the air condition unit And also put one on the ac unit where it is going to touch the aluminum square. I figure I can put a little bit of self leveling sealant at the outer edge of the aluminum tubing and the roof since there's already a little dip there. If this proves not to be satisfactory I can always go in and add the U Channel later. Any input is welcome. Quote Link to comment Share on other sites More sharing options...
rusticandy Posted August 2, 2013 Share Posted August 2, 2013 That sounds like a doable fix. It probably wont fix the sag, but it should arrest it if you used heavy gauge bar stock. Id put the gasket material all along the bottom of the aluminum H frame, and not just around the AC opening, otherwise you are compounding the sag. You can sand the weld joints flat with a regular RO sander or grinder to miprove the surface so the seal is better. The AC bolts will sandwich it all together Good luck!! Quote Link to comment Share on other sites More sharing options...
grandview bill Posted August 7, 2013 Share Posted August 7, 2013 hi im not sure are you doing this supporton the inside or outside?Bill Quote Link to comment Share on other sites More sharing options...
mandjmckinney Posted August 8, 2013 Author Share Posted August 8, 2013 I finished the project using one and one quarter inch square aluminum tubing welded into a Square with inside dimensions the size of my AC opening. I used the standard square gasket for air conditioner openings on the bottom and a different gasket on the top of the square. I used caulk to put some rectangular aluminum on the roof at the back of the AC for support with some foam on the top of it. I then pulled it all down by putting the bolts back in on the inside. I used the 3/4 inch dip in the roof to my advantage by applying 5 tubes of self leveling sealant on the aluminum tubing and letting it run down into the sag area and cover the gasket as well. This basically makes a water tight seal over the top of my gasket. Quote Link to comment Share on other sites More sharing options...
mandjmckinney Posted August 8, 2013 Author Share Posted August 8, 2013 We're heading out on a trip this weekend so we'll see how well it worked Quote Link to comment Share on other sites More sharing options...
mandjmckinney Posted August 15, 2013 Author Share Posted August 15, 2013 On the road for a week. Experienced rain along the Gulf Coast. The roof sag filled with rain water at times and condensation from the air conditioner at others. No water on the inside. I'll try to post a picture of the repair as taken from an observation deck on a ferry Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted August 27, 2013 Share Posted August 27, 2013 I've had 2 of these RV's == both had a little sag - when parked level I would get a good run off after moving on. In storage I would not park level on purpose. Saw 1 of these in Acadia NP a few years ago -- they had what looked like angle iron made into supports Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.