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leaking seams

Post in 'DIY and General non-hearth advice' started by Beetlman, Sep 29, 2007.

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  1. Beetlman

    Beetlman New Member

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    Hello.
    I have a 30 by 12 foot structure that is about 30-40 years old with 2X4 rafters @24"OC and a low slope shed type corrugated metal roof which is bright and shiny but leaking at the seams. I bought some BlackJack fibered roof coating for it But I need to seal the seams first before I coat the roof. It appears to be leaking Only because of the seams which are overlapped one corrugation and there doesn't appear to be any sealant in between them. I guess I need to get up there somehow and apply some sealant then tape then more sealant and then let that fix cure before I apply the aluminized fibered roof coating. I have Never done this before but it does sound simple enough. However I am concerned about the age and spacing of the 2X4 rafters (they are old but seem sound). Under the metal roofing is some old gritty tar [paper and under that are long 30 foot tongue & groove one inch boards.
    Of course just getting up there will be an accomplishment cause I don't like ladders or openair heights. If I don't look down and concentrate on my Job though I should be ok.
    Should I build some sort of scaffolding ? What would be the best way to do this job short of hiring out as I don't have the money to do that?
    The front of the roof is about nine and a half feet high but I can reach the top of the back as it is less than six feet.
    Any suggestions?
    Thanks

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  2. Hogwildz

    Hogwildz Minister of Fire

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    Some photos of the roof would help. If those seams are vertical, the should not be leaking. Are the metal panels screwed on with neoprene washers under the screw heads? or nailed on. I would NOT trust walking on 2" x 4"'s, Unless you weigh about 80 lbs. What you need to do is by some good roof grade double sided tape. Unscrew the seams one by one and install the double sided tape between the layers at each seam, then re-screw with new neoprene washered screws. Why aluma coat it? Why not get a good grade metal paint and paint it? I would do it off the scaffolding & the back side if possible, just sounds like your gonna go through to me.
  3. Beetlman

    Beetlman New Member

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    Hi Hogwildz
    I'll take some photos tomorrow. The seams are vertical and the panels are like 13 feet long. Meaning they are going high to low ... in that direction. There is a structure to it's immediate side and the wind seems to always blow from the otherside into the seams and pushes the rain going down the lowslope into the gap between the seams and then it leaks somewhere inside. It doesn't leak inside in the same place all the time and right now I can see where it leaks cause there is no ceiling so I can see the whole bottom of the roof. They appear to be nailed properly with those rubber ringed roofing nails but no caulking between the seals. Some I can see on the lower side that are open (gapped) like maybe an eighth of an inch or more. I got wet today standing in the rain watching it hitting on the roof and seeing what it does. The wind was hardly blowing too! But I could see the rain going into those gaps and water coming from between the overlapped sheets. There is only one corrugated overlap for the low slope it probably should have been overlapped two or three?
    The double sided tape method is better than the sealer/reinforcement tape/sealer method which glues in between and covers across over the top?
    80 pounds ? nope, 135ish. Scaffold would have to go completely across the thirty feet and above (off) the roof? Or is there a much better scaffolding way for this?
    I'll take some pictures tomorrow.
    Thanks for your help.
    Beetlman
  4. Beetlman

    Beetlman New Member

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    Hello
    Here are some pictures of the roof. You can see the gap overlap and looking at the situation through the camera I notice another source of problems may be on the front where there is no flashing? Should there be some sort of flashing to cover the panels, especially in the front? Well, I'm attaching the files ... I assume they're going up. They did but the thumbs look a little weird. Clicking to open them up gives the better picture though.
    Thanks

    Attached Files:

  5. Hogwildz

    Hogwildz Minister of Fire

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    Ok I can see the photos.
    From what I see, the top right photo says it all. Just to the left of the seam, your can see someone walked on the panel, causing the panel at their foot to bow down, hence causing the seam to the right of it to warp and open up. I was thinking a slightly different metal roofing, the flat ones with the raised ribs every foot or so. The "wavy" type stuff you have, well, I would have overlapped 2 over instead of one. That way any water that did find its way in, would hit the low rib and run down between the panels. If its nailed on, chances are some of those nails are working back out. A bit late to try and double lap them now. I suggest a good double sided butyl tape. And screw the seams down in place of the nails. That way you are sandwiching the butyl tape between the layers. How often are the nails? every 12", 18"?
    The good part is, if you do go with the double sided tape, when you have the seam open, you should be able to flex the panel at the seams back into its original shape by hand. Meaning put the arc back into it. You might want to wear leather work gloves while trying to reshape, as those edges will slice ya good. If you walk on that roof, it will only buckle the panels more, most likely opening more seams up. As I said pull the nails, put your tape in the seams, the replace the nails with roofing grade screws with neoprene washers on them. If you see opening as you go in between where it was nailed, ad another screw in between to tighten those gaps up. Just snug the screws real well, Don't suck the seam flat.
    Now, tape placement. I would put a strip of the tape near both edges of the seam, and screw it down between the two strips of tape. It you try and screw through the tape, the screw will most likely grab the tape and you'll end up with a tape ball around the screw, and tape missing from where the screw grabbed and ripped the tape.
    I would try this method first. Let it go though a few heavy storms. And if it holds, coat, paint whatever. If it still shows signs of leaking, then consider muck & taping the tops of the seams, or whatever way you want to seal them from top. The problem with the muck & tape, is the metal will expand & contract, and in no time that tape & muck will end up coming loose. And it will then suck to get off.
    Besides tape, you can also try urethane caulk between the seams. Very good caulk, can be had at any hardware store, Lowes, Home Depot etc. Not cheap. but if you seal between those seams with it, and screw it down real good. No water will get in there. And it stays flexible forever. Will move with the panels expanding & contracting.
    Note that it is very messy if you get it on you. The caulk itself can take days to a week or so to fully set. But is the best caulk made.
    I would save covering the seams as a last resort. Once you cover them, if it doesn't work or you need to get to the seams, it will be a mess.
    The choice is ultimately up to you though.
    Are those 2x4's trusses, or actual single board rafters?
  6. Hogwildz

    Hogwildz Minister of Fire

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    As far as the face boards, depending what the building is. I wouldn't do much.
    You can cap them aluminum. If its basically an out building, just leavem be. Are they still in decent shape?
  7. Beetlman

    Beetlman New Member

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    Thank you Hogwildz
    You pretty much explained the whole procedure(s) even what to watch out for and what not to do. Thanks.
    RAFTERS are single and being 24"OC and already maxed out spanwise isn't very good in my opinion.
    I'd like to put up a ceiling (even though it would be sloped) but those rafters won't hold much. Someone suggested Sistering them to make them stronger. I was thinking sistering what I felt structurally needed sistering and then adding More rafters in between to bring them to like 12"OC . Would sistering each rafter with 8 feet in middle of the span be stronger than bringing them to 12"OC ? Not much snow here in Oregon .... mostly Rain.
    Would either method allow for them to support a lightweight ceiling?
    Thanks
    Beetlman
    PS..... HOG Once they started those commercials putting down Cavemen I QUIT Geico.
  8. Hogwildz

    Hogwildz Minister of Fire

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    I have only seen 2x4's ever used in a true truss system.
    What you have there is just aching to cave in some day.
    The only way I would sister that is with at minimal a 2x6, preferably a 2x10.
    The only problem is, you don't have the height. Is this roof one sided? just what shows in the photos?
    At 12' x 30' I am assuming 12 from lower edge to top, and 30' is the length side to side?
    If you ran 2x4's in between the ones already there, that would put them about every 12", that would surely be better than what you have, but still not ideal.
    Is there a way you can run 2x6's or 2x8's in between and use joist hangers at the ends? I would not bother sistering, you still have that far spread in between. Which
    is part of the roof problem. Not enough support in 2' centered rafters. Like I said if you can get something in between, better than nothing.
    Try and set them so they run under a high rib in the roof. Then you can faster the roof even more in between where it is fastened now. Which will help support & keep the roof from flexing in between the rafters.

    If you can get joist hangers to work I would go that route with like a 2x8. Thats just me though.
    As I said earlier, anything you can run in between to cut that 2' center of rafters down to a smaller span, will be of help.
    Is this a living structure? or more of an outbuilding?

    Also as for hanging drywall. As it is now, I wouldn't. If you can get some more rafters in there. Then maybe you can.
    your other alternative is to run level horizontal 2x6's or 2x8's from the front wall level across to the back wall, depending on what you have to nail to back there. and hang the drywall from there. It will also be level that way, instead of following the roof pitch. And better yet, you could run them, get some truss plates at Home Depot or Lowes, and make trusses by nailing 2x4"s from those level ceiling joists you just installed to the bottoms of the 2x4" rafters on angles just like a regular roof truss.
    Theres many possibilities. Depends how much you want to do, what the space will be used for, and how much time, effort & cash you want to put into it.
    If its going to be living space, I would do it right. Last thing you want is a roof collapsing on you while your sleeping or or in the middle of something.

    Its ok, Ive been told I am a Neanderthal, thats the joke. I just used the Caveman as my thing. I had Geico, they suck.
  9. Beetlman

    Beetlman New Member

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    Thanks Hogwildz
    I was over my neighbors yesterday and he showed me his outbuildings. They also are 2X4 rafters BUT looked like 16"OC and Not spanned out to the max. Lucky him.
    Irregardless of the fact the roof and building has been standing over 35 years, I realize that THAT fact simply makes the odds of it (caving in) higher at this time without some rafter beefing up. Lot of information and ways to fix the problem in your last post to mull over. Seems like with the leaky roof (raining today again) and the rafter situation I could use a new roof. Course as soon as I start dealing with rafters, trusses or ceiling joists I would need to pull a permit which I don't think I'd get due to the fact my Dad got a permit variance when he put the other structure up on the footprint of the one he tore down which was in nonconformance to codes being 8 inches apart. From my reading of the Codes THAT means I can't do much of anything which would increase the longevity of the nonconforming structure and it would either need to be let fall down, taken down or brought into conformity by removing about ten feet? of it when it needs to be repaired. Bummer.
    Looks like I was wasting my time and little money to follow a dream that wouldn't be allowed.
    I have the other structure as a gift shop already and my customers up here on the mountain want me to fix that Red Shed/barn into a 2nd hand store like a Salvation Army or Goodwill. I was planning to give 50% to the humane society from those sales But with these problems it appears I am up against a wall too high to climb.
    There is One partition wall 6 feet from one side exterior wall. I was planning another partition wall around 10 feet from that with both walls running parallel to the rafters I Was thinking they may support a beam to support shorter span ceiling joists as well as the rafters as the supported *doubled 2X4* would run under the rafters ... but again the permit falls into play. Would Plywood attached to the bottoms of the rafters as a ceiling tie them together and make it all stronger if supported by those inner walls AND Cabinets and shelves of 6X2 structure which go floor to ceiling (rafters)? Cabinets and shelves don't need a permit and could be used to support ceiling (roof structure) like walls as they would be over the Floor Foundation supports? Doesn't appear permit needed to Repair (sister) damaged or weak areas either. Once done, it should all be strong.
    I only planned to keep this up for two more years and after Business picked up and I got financially squared away I was going to replace it with another structure. .
    Maybe a petition signed by my customers and neighbors up here asking for a varioance to allow the repair and limited usage for a restricted time and then tear down and replace? Have you ever heard of Building Inspectors listening to the community in regars to variances like this? It isn't that I want to MASK or HIDE the problems. I want to do it all structurally safe and to code as much as possible and I sure don't want the roof to collapse! It's just that I could probably get a Change of Use Inspection Permit AFTER it was done as a Storage Shed but a Builders Permit to get it done that way would more than likely not even be issued because I would be extending its Life. Why didn't they just have my Dad rip it down if they didn't want it there? Wouldn't the plywood on the rafters add support to them providing I also supported that plywood with my walls and 24 inch wide shelving units framed with 2X6 or 2X8s running floor to ceiling (LIKE A WALL ...that looks like wide storage shelves)? I would do a section at a time and NOT put all the plywood (ceiling) up before the Support (walls and shelves) for it was in place. Especially with some sisters up there.. If it wasn't for the roof and ceiling I would have been done by now with no problems.
    Thanks for all your info and help
    Beet
  10. Hogwildz

    Hogwildz Minister of Fire

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    I myself would do what I needed to do inside, no ones going to see you if your careful about it. Add the extra rafters, and the shelves as support. And go from there.
    If you have to, buy the wood at night and carry it in in the dark :) Incognito like.
  11. Beetlman

    Beetlman New Member

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    Thanks Hogwildz
    The plywood up there as a ceiling being supported by the *storage shelves* would add support to the roof in your opinion?
    Would you recommend Long Fat Screws (1 1/2 inch) or some kind of nail like maybe the kind with the spiral around the shaft for holding the plywood up there and securing to the rafters?
    Wood is no problem there is a guy further up the road that sells plywood and works at a lumberyard.
    Everyone around here including the UPS deliveryman keeps telling me all the stuff they have done without a permit .... including rafters, Full height walls, hot tubs, plumbing and electrical ... but I don't want to get in trouble.

    thank you
    Beet
  12. Hogwildz

    Hogwildz Minister of Fire

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    Heres what I would do in your situation. Keep in mind this is my opinion, and thats all.
    I would 1st get the roof leaks stopped and under control. When I felt it was tight, I would add those rafters in between the others, The I would consider drywall, as it is much cheaper than plywood. No sense spending a ton on plywood if your going to renovate in the future sometime. Use coarse thread drywall screws something like 1-5/8" should do fine. Then yes strategically placed storage shelves up to the drywall. Just don't forget to mark where your rafters are so you can screw the shelving into the rafter once up. I am not big on permits, it seems more a thing about upping your taxes for improvements, then a safety thing these days.
    I am pretty proficient in construction because I worked in it for many years. I did my addition all myself and did not pull a permit. I might catch heck for it, but it is America supposedly. If I had a feller like Elk around here, I would certain seek guidance from such a man. I know after fixing the previous owners crap work as I am going, that I did a much better job. I was not afraid to buy some books to use as reference & to brush on on things I haven't done in a while. That helped alot.
    I would also consider again, If you can get 2x6 or 2x8 rafters in there with joist hangers front & back, you wont need to section off so much with shelving for support.
    Just a thought.
  13. Beetlman

    Beetlman New Member

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    Thank You
    I'll let you know how it turns out.
    If I could add 2X6 rafters in there they would essentially be my ceiling joists (lowering the ceiling 2inches) and act as RafterTies as well as support the roof and give me the needed space to insulate. We'll see what happens. This building wasn't even in the books when my Dad got the permit for the replacement of the one next to it. I pray. I'm not asking for the Red Sea to part Just a couple years of Safe Usage of that structure so I can climb out of Debt and then be able to (go in debt again) :p to tear down and replace with a more proper building ... maybe even as a Very Large addition and connect the two and try to keep the old Barn look going so it all would fit in nicely up here.
    People keep asking WHY Open a store up here wouldn't I do better in town. Well, up here I don't have Rent for the store space and as much $ I can squeeze out of my assets, obviously the better. Plus they are Building more residentials around here and I know the market will be even better up here in a few years when I can *retire*. I do miss restaurant work sometimes but my body just can't do that anymore.
    Thanks for the well rounded advise Hogz.
    PEACE
    Bob
  14. Hogwildz

    Hogwildz Minister of Fire

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    Yeap them 2x6's would solve alot of problems in one shot.
    Good luck on the project, take your time & do it right the first time around. :)
    Glad to have been able to help. Holla any time ;)
  15. Rhone

    Rhone Minister of Fire

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    Wood gets its strength through thickness. A single 2x6 is stronger than two 2x4's put together. A single 2x8 is stronger than two 2x6's put together. But two 2x8's is stronger than a 2x10 (but a 2x10 is stronger than a 2x6 & 2x8 put together). A 2x12 is stronger than a 2x10 & 2x6 put together. You'll have a stronger and stiffer roof with 2x8's spaced 24" apart, than 2x6's spaced 16" apart.

    It happened all the time in the old days using small rafters. My house & span requires 2x12 rafters but my house was built with 2x6's, which are 1/5th the strength! My roof sagged something terrible and I ended up building a structure from my basement and jacking up my roof until it was straight (and make sure it doesn't pop off the top plate else you're in for a world of hurt) and I sistered them with 2x12's full length! I positioned them to rest on the top plate and went all the way to the ridge and loaded it up with a nail gun to my 2x6's. Took 4 hours per rafter x 70 rafters = 280 hours. I'm a glutten for punishment, had I just sistered them instead of going full length sistering I'd probably been able to have done it in 40 hours but, I'm a perfectionist.
  16. Beetlman

    Beetlman New Member

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    Yeah, Perfectionist. I take a break working and I'm going around with my Wood Glue filling in every little space in the wood anywhere I find it. I know it adds diddly for structural strength but I can't stand seeing little imperfections like that. :) Good stress reliever though.
    Master of Fire .... simply sistering will add rigidity to the rafters BUT won't it also add extra weight to the roof structure if not going full length and supported somewhere?
  17. Rhone

    Rhone Minister of Fire

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    You don't have to go full length, only 3/4ths and centered on sag but more can't hurt. To explain why you don't have to do the full distance, the place that fails with long spans is the middle and, with the middle being reinforced we shift that failure towards the ends which, it takes a lot more weight to have an end fail near a support so hence makes for a much stronger system as a whole. Think of how much weight a 3' 2x4 can hold before it fails, if it ends up there's only 3' of the rafter that's a 2x4 at the ends, and the center is reinforced with 2x8's that system can handle multiples of more weight before failing than the original system.

    Ugg... I'm not good at explaining things. The only time one must sister the whole span is when the original rafters are cracked, split, or rotten particularly at the ends.
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