Dryer venting question: part 2

Discussion in 'General Home Improvement Discussion' started by Billbill84, Sep 16, 2019.

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  1. Sep 16, 2019 #1

    Billbill84

    Billbill84

    Billbill84

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    hi guys. So my current setup for the dryer venting is a crappy flex tube behind the machine and it goes to a metal flange or elbow through the wall, then as it passes directly through the wall into the garage (see pic below), after elbow it's a 4.5 ft piece of flex tube in a box to house the flex duct as it goes to the outside wall vent. I learned on here, about the magVent set up but I'm wondering if that wall box is still required by code to house the new replacement metal duct that I'm going to install?? Should I just leave the box there and just cut out the bottom and do all my work from below? Not sure if some sort of firewall is required by code I don't wanna deal with it later should we sell the place. Thx
     

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  2. Sep 16, 2019 #2

    nealtw

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    The box is there to give you a positive air seal between the house and the garage, so it should stay. So if you have to open it to work on the duct, plan on repairing it.
     
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  3. Sep 16, 2019 #3

    billshack

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    the code says that outside a wall or floor you are allowed flexible dryer vent. However inside a wall you must have metallic piping . the reason for this is that dryer lint is extremely flammable . just for fun take a small piece of dryer lint put it in a metal container and light it.
    Also the code calls for the last 4-5 feet of dryer exhaust must be insulated.
     
  4. Sep 16, 2019 #4

    Snoonyb

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    Since I vent with metal ducting, I would remove the box completely and vent with 4" round steel venting, wrapped with fiberglass duct wrap, sealed on both sides of the firewall penetration with fire caulk.
     
  5. Sep 16, 2019 #5

    nealtw

    nealtw

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    Separation between house and garage is drywall with a min of taped joint with one coat of filler over that.
     
  6. Sep 16, 2019 #6

    Snoonyb

    Snoonyb

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    And...............
     
  7. Sep 16, 2019 #7

    nealtw

    nealtw

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    The box is in the garage so it is that separation.
     
  8. Sep 16, 2019 #8

    Snoonyb

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    If the box is removed and round sheetmetal ducting is used, with a fiberglass sleeve, and there is fire caulking on both sides of the wall penetration, the firewall is maintained, provided that the wall behind the box was complete, and the box was added to protect the flexible venting.
     
  9. Sep 16, 2019 #9

    Billbill84

    Billbill84

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    IMG_9939.JPG This is the current mess behind the dryer that I want to eliminate. I just realized that I'm unsure if the magVent will even work because notice the vent out on the machine vs where the vent out is on the wall. It's over about a foot-foot.5! Might have to pop a new hole just so the magVent fittings will all line up correctly. Ugh, why does every simple job turn into a cluster f!
     
    Last edited by a moderator: Sep 17, 2019
  10. Sep 16, 2019 #10

    nealtw

    nealtw

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    If I have it figured right you could move the duct over to behind the dryer and still be in the box outside.
     
  11. Sep 16, 2019 #11

    nealtw

    nealtw

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    Why would you change something that is built to code? The drywall is also fire protection.
     
  12. Sep 16, 2019 #12

    nealtw

    nealtw

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    there are two models
    [​IMG]
     
  13. Sep 16, 2019 #13

    Snoonyb

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    It's "built to code", to protect the flex-i-duct, and no other reason.

    Had they used round steel venting material as I listed, they would not have needed the box, at all.

    KISS principle.
     
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  14. Sep 16, 2019 #14

    Snoonyb

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    As Neil has provided examples of, there are several alternatives to the MAG vent system that will fit your configuration.
     
  15. Sep 17, 2019 #15

    nealtw

    nealtw

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    Any duct running thru the garage needs to be boxed where i am, it seem it is a more local rule in different places so the poster should check.
     
  16. Sep 17, 2019 #16

    Snoonyb

    Snoonyb

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    Also, ask why.
     

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