strange Roof leak

Discussion in 'Community Discussion' started by 63dot, Jan 20, 2010.

  1. 63dot macrumors 603

    63dot

    Joined:
    Jun 12, 2006
    Location:
    norcal
    #1
    I live in a standard house with a slanted roof, vs. the flat roofed, leaky place I used to be in.

    For many years, there are almost no leaks in this '50s built house, but when it rains, and the wind blows from a certain direction only, I get a few drops of a leak and then I won't see it again for a year or more. It's only on north side of the house and I am on the West coast of the USA.

    What could be causing this?

    One roofer said this is common and happens to slanted roofs even when they are brand new.
     
  2. MultiM macrumors 6502

    MultiM

    Joined:
    May 9, 2006
    Location:
    TO. I've moved!
    #2
    Leaks should not just happen and be "common". Leaks are caused by poor workmanship or bad materials. that being said, the next time it rains, and you get this leak, go up into the attic and see what is. The insulation should be damp over the leak so look up. You'll see the source. If not, pull it up and see if it's wet under the insulation. If not, then it's probably not the roof. It could be the siding/brick or whatever is facing your house. It could be blowing up from under the eves/facia. If the leak is near a window, it could be poor sealing. Water can get in almost anywhere if you let it. Without more info from you, I couldn't hazard a guess.

    Find someone else to inspect rather than that guy.
     
  3. 63dot thread starter macrumors 603

    63dot

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    norcal
    #3
    Thanks for the info.

    Come to think of it, that guy belongs to the biggest, and really the only roofing company that isn't a family business with a few workers, so his motivation is to redo my whole roof. They do the roofs of all the schools, churches, government buildings and they think big and fast.

    Too many around here have claimed their work is bad, and they remind me of the Wal-Mart of roofing businesses in my county. I could see how "thier" work would have common issues with leaks right after they put a roof in. He also told me they have "redos" since it's a very tricky thing to put in a roof that can keep "all" water out. Either he is telling the truth or he is a master salesman from a very large company. ;)

    When I get that leak again, whether this year or three years from now, I will have to go up into the attic and find the source. It only lasts for a few minutes and I will have to get to the source before it dries. I don't look forward to it, but it's the only way I will find this very intermittent and elusive source.
     
  4. xlii macrumors 68000

    xlii

    Joined:
    Sep 19, 2006
    Location:
    Millis, Massachusetts
    #4
    I live on the east coast and here we get lots of rain and having a foot or more of snow on your slanted roof isn't uncommon in the winter. Your roof should be plywood bottom, then a waterproof liner, and then a final layer of shingles. The previous writer was correct... your roof should not leak ever.

    Besides waiting for the next heavy rain. Could you try using a garden hose to simulate the rain coming in from the side you think is causing the leaks. You could have a friend use the hose while you go up into the attic and see where the leak is coming from. This way you could do it in the daylight, on a nice day... when it is convenient for you.
     
  5. Mousse macrumors 68000

    Mousse

    Joined:
    Apr 7, 2008
    Location:
    Flea Bottom, King's Landing
    #5
    I had the same problem when I brought my house. During a thunderstorm, sometimes it would leak, most of the times not. It had be baffled, for a weeks until I paid attention to the wind direction. I leaked only with a stiff north wind. I climbed onto the roof and discovered that the whole shingle above the leaking area was loose.:eek: When the wind blows hard enough to lift the shingle, rain water gets driven into the gap.
    Piss poor workmanship, no doubt. The nailing pattern was a dead giveaway as well as the uneven spacing of the shingles (the rows would vary from 5.5" to 6.5":eek::eek::eek:) I applied some roofing cement to hold down the loose shingle temporarily until I could replace the roof.
    There's a good chance the OP's roof has the same problem.
     
  6. Rodimus Prime macrumors G4

    Rodimus Prime

    Joined:
    Oct 9, 2006
    #6
    My only thinking on how it happens is slanted roof use the shingles overlaying each other and when the wind blows the right direct it can start shoving water up the slop of the roof and there for under the shingles. The flatter your slop roof is the greater the chance of this happening.

    That being said it should not leak. Wind can damage a shingle and cause it to lift and allow water to get under it.

    Some one else explain how a shingled roof works. Leaking is a problem with wind is a common problem but still a problem and is not acceptable.
     
  7. Gregg2 macrumors 603

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    May 22, 2008
    Location:
    Milwaukee, WI
    #7
    That was pretty good. I mean, that's why there are minimum slopes for various types of shingle installations.
     
  8. 63dot thread starter macrumors 603

    63dot

    Joined:
    Jun 12, 2006
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    norcal
    #8
    It's that stiff north wind, or northeast if I am gauging the wind right. The south winds and west winds last night did nothing.

    And not just a stiff North or NE wind, but something exceedding 50 or 60 mph. Short of that, there's no leak.

    I can't replicate this condition with a hose so I will have to go up in the attic pronto when and if we get one of those northeastern storms and heavy wind. Knowing my luck there will be no leak and I will have to wait until next winter.

    The roofer said with the right wind, the capillary action could eventually bring water into a small hole, have their be a few ounces of water getting through, and then force that 1/2 ounce of water getting into the house. It's not a lot of water but it's where I keep my computer and guitars so it really bugs me.
     
  9. MultiM macrumors 6502

    MultiM

    Joined:
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    TO. I've moved!
    #9
    .....or you could go up onto the roof and inspect the shingles around where the leak is. Just remember to cover a fairly large are because water can travel from where it enters.
     
  10. 63dot thread starter macrumors 603

    63dot

    Joined:
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    norcal
    #10
    The shingles look good everywhere. I suspect a minor leak coming from a small hole nearby under the shingles and tarp. I won't rule out water leaking in through a small fissure high in the north facing wall. Even though this leak has its dry water marks on the ceiling that go back until at least the late 80s from when it was a rental, it's the most elusive thing.

    The obvious is easy to detect, fix, and get over. This won't be obvious and we may call over a specialized carpenter who does fixes for roofs after busy roofing companies miss an area.

    Where I live, the building codes only require minimum flashing and tar and tarp around a brick chimney. He comes in and heavily tars the area and puts bigger flashing on and has repaired many weaknesses in that area of roofs in neighborhood homes. We will call him over to fix these issues.

    When we had a fence which experienced rotting after just 7 years, we called him in and he fixed it. The original contractors used redwood and it held up OK, but our guy uses treated construction heart redwood, and that fence is still close to new 11 years later.
     
  11. Zombie Acorn macrumors 65816

    Zombie Acorn

    Joined:
    Feb 2, 2009
    Location:
    Toronto, Ontario
    #11
    You will never have leaks with a well roofed house. The base wood material is covered with tar paper which is overlapped over the entire roof, this is nailed down in the overlapped positions to ensure that you have 2 sheets of protection where the nails go through to secure the paper. On top of that you place a starter strip at the base and then caulk the nail holes, then layer your roofing shingles in tiers so that the next shingle up always covers the holes the nails create, and then a roofcap is put at the top to make sure no water can get through those nail spots, the last of the roof caps have an exposed nail which is caulked over.

    There really isn't any reason water should get under your roof unless the shingles are just poorly done.
     
  12. MacNut macrumors Core

    MacNut

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    Jan 4, 2002
    Location:
    CT
    #12
    Do you have a ridge vent or any open air ducts in the attic?
     
  13. Macky-Mac macrumors 68030

    Macky-Mac

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    May 18, 2004
    #13
    Or getting old......shingles do get old and deteriorate, then they need to be replaced
     
  14. MacNut macrumors Core

    MacNut

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    Jan 4, 2002
    Location:
    CT
    #14
    Shingles are supposed to last 15-30 years.
     
  15. Rodimus Prime macrumors G4

    Rodimus Prime

    Joined:
    Oct 9, 2006
    #15
    little high there. Asphalt shingles are designed for around 10 years. 15 years is the upper limits of the design.

    Asphalt shingles are typically is what is used on homes today. They are the cheapest per year to use.
     
  16. MacNut macrumors Core

    MacNut

    Joined:
    Jan 4, 2002
    Location:
    CT
    #16
    I know in hurricane areas everyone has to use 140+ mph shingles. I think they are rated higher. All new roofs have to be architectural shingles here.
     
  17. scottkifnw macrumors regular

    scottkifnw

    Joined:
    Jan 17, 2008
    Location:
    Trophy Club, TX
    #17
    Excellent suggestions

    I had problems with flashing as well, so check that too.

    sek

     
  18. Gregg2 macrumors 603

    Joined:
    May 22, 2008
    Location:
    Milwaukee, WI
    #18
    You're a little low. From http://www.roofhelp.com/choices/asphaltshingles/

    Many shingle manufacturers advertise a 25-year warranty. From the data above, perhaps the optimism is unwarranted.
     
  19. Zombie Acorn macrumors 65816

    Zombie Acorn

    Joined:
    Feb 2, 2009
    Location:
    Toronto, Ontario
    #19
    The funny thing about shingles is that they have raised their duration rating yet are being made thinner and cheaper every year. :D
     
  20. 63dot thread starter macrumors 603

    63dot

    Joined:
    Jun 12, 2006
    Location:
    norcal
    #20
    Those plastic, or as they call it asphalt tiles, are meant to last what?...10 to 15, or even 20 years?

    They are ugly and unfortunately, I have them.

    On ABC news radio, there was a topic on human made trash and how to address this growing problem from computers that were too old, to carbon emissions, to roof tiles. Researchers at MIT found these tiles, which were engineered to last "longer" than a wood tile, lasting in the 50-100 year range. There was no easy way to dispose of these, and like styrafoam, we have this indestructible product that takes too long to break down.

    The upside is that you won't get leaks, or if you do it will be some anomaly which I now have narrowed down to water blowing in a hard north rain into the paneling a foot and a half above the windows where there is a 1/16" inch gap between the wood and the stucco on the outside.

    The downside, besides being ugly, is that if thrown into a landfill, they will take far too long to break down.
     

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