crack in rafter

Discussion in 'Framing and Foundation' started by minimii, Jan 4, 2013.

  1. Jan 4, 2013 #1

    minimii

    minimii

    minimii

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    My house was hit by a tree during Sandy. A few rafters was broken/cracked. The roof contractor had come and replaced a few broken rafters. However, I found there are still 3 rafters with cracks, some about 2 to 3 feet long, not being replaced or reinforced. I wonder if I should insist to have the roof company replace them. In the attacked picture "cracks.jpg", you can clearly see some of the cracks.

    Another issue I have is that the last rafter that is next to the back side of the house was broken. The contractor only replaced half of the rafter, not the whole piece, as see in the picture "joint.jpg". Does it matter?

    cracks.jpg

    roof-truss.jpg

    joint.jpg
     
  2. Jan 4, 2013 #2

    nealtw

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    I don't see anything that would cause a problem. The long crack is likely a result of drying and is not part of the damage the tree did. The other photo, the patch is sitting on the beam and would have been fine evan if it were shorter. All it does is connect this roof to the other wall.
     
  3. Jan 8, 2013 #3

    BridgeMan

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    Longitudinal cracking in a roof rafter, when occurring near the neutral axis like yours are, shouldn't present a problem. However, if you are in an area subject to heavy snow loads, you would do well to sister in "doubler" (glue and screw) 2x plates to tie the original rafters back together. They cannot function as a single unit if split into parts, and heavy loading will make the splits worse. I'd also be concerned about your roofer replacing just portions of rafters, unless he made an effort to adequately splice the junctions between new and old. Not clear from the photo what the splices are. A rafter is usually installed as a single member, meaning it's continuous from one end to the other, over any/all intermediate vertical supports. Changing from continuous to simple span will decrease the overall strength of the member by about 20%--usually not a problem unless loading conditions are such that actual member stresses increase up to (or beyond) design values.
     
  4. Jan 8, 2013 #4

    Wuzzat?

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    Rafters are designed to withstand a distributed load in lbs per linear inch but you can put a concentrated/point load on the questionable rafters while standing over the weakened area and having a helper measure deflection from inside or outside using a straightedge or line.
    Then, compare your readings with several from known good rafters in comparable roof locations to get a quantitative measure of how much the rafters are compromised, if any.
    If there is noticeable deflection from just the weight of the shingles, you almost certainly have a problem, but compare measurements.

    Actual numbers make a lot of people sit up and take notice.
    It conveys the idea that you are
    diligent, knowledgeable in mechanics, aware of forces on structural members and knowledgeable about strength of materials. Plus you have some skin [& money] in this game.
     
    Last edited: Jan 8, 2013
  5. Jan 9, 2013 #5

    nealtw

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    inspectorD likes this.
  6. Jan 16, 2013 #6

    minimii

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    Thanks everybody.

    nealtw, should I hire an independent engineer or the contractor should provide the report?

    BridgeMan, the contractor did not splice the two piece together. The two pieces are just sit there exactly like in the picture. I understand not replacing the cracked rafter and not using a single rafter for the two pieces shown in the picture probably would not make the house fall apart, not anytime soon. However, I am unhappy because insurance company had agreed to replace the pieces. It was the contractor trying to cut corner and save a few bucks. At this stage probably it is too late for me to do anything.
     
  7. Jan 16, 2013 #7

    nealtw

    nealtw

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    It is somewhere between the insurence co. and the contractor, they or anyone should not touch the trusses without and engineers instruction and you should get a copy of the report from the engineer.
    When you sell your house an engineers report will be required, so you should go after it now.
    The job is simply not finished. When an engineer does show up make sure he sees anything you have concerns about. They take no chances and are likely to have things fixed , needed or not.
    Call a local truss company and ask about the repairs, They will tell you to get and engineer. Ask them to put that in writing so you can send a copy to the insurance company.
     
  8. Jan 17, 2013 #8

    BridgeMan

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    If you leave things like they are (with your roofing contractor laughing all the way to the bank), you will pay for it come time to sell the property. A ballpark guess is that any buyer will automatically deduct at least $1000 from his offering price once his home inspector finds the mess left behind in the attic by your contractor, and quite possibly several times that amount.

    If you can live with that, then so be it. If you can't, it's time to go after the roofing contractor's building license, followed by filing a claim in small claims court to cover the cost of a proper repair, done by someone who knows what he's doing.

    And for what it's worth, the photos don't show any trusses in your attic. All that's visible to my untrained eyes are simply straight rafters, with some vertical intermediate supports to prevent over-spanning.
     
    Last edited: Jan 17, 2013
    nealtw likes this.

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