Results 1 to 8 of 8

Thread: Enlarging a deck

  1. #1

    Enlarging a deck

    I have an existing deck off the back of our house. It is time to replace the decking. We want to enlarge the deck the same time that we replace the decking with composite materials. The existing deck is shown in the first photo below. The planned extension is shown in the second photo. My question is whether to remove the skirt board from the existing deck and splice on the joists for the extension to get to the new length or use joist hangers and hang teh ends on teh outside of the skirt board and build the frame for the extension as shown in the second photo. The current joists are 2 x 8. The doubled supports that run left to right are 2 x 8's as well. Hopefully you can read the dimensions.

    I'm concerned whether the extension will be stiff enough with only one support beam under the new portion and the joint being just joist hangers. Will it tend to flex if several adult sized people get on the outside edge of the extension. The extension over hangs the support beam by about 25".
    Attached Images Attached Images
    Lee Schierer - McKean, PA

    My advice, comments and suggestions are free, but it costs money to run the site. If you found something of value here please give a little something back by becoming a contributor! Contribute

  2. #2
    Join Date
    Dec 2006
    Location
    Auburn, ME
    Posts
    707
    Lee,
    Is there a reason why you can't pull off the skirt board and then run your new joists from girder to girder with a new overhang?

    I don't think I would suggest using just joist hangers to hang off the 'skirt' board and then have another extension off the new girders. Another option would be to eliminate the overhang and pull the support girder out to the edge then it might be ok to just use joist hangers as you would be simply supporting each end of the beam.

    Greg

  3. #3
    Join Date
    Feb 2009
    Location
    Gods country: Mariposa CA
    Posts
    839
    I would pull the skirt off and sister the joists back to the girt

  4. #4
    Quote Originally Posted by Greg Cuetara View Post
    Lee,
    Is there a reason why you can't pull off the skirt board and then run your new joists from girder to girder with a new overhang?

    I don't think I would suggest using just joist hangers to hang off the 'skirt' board and then have another extension off the new girders. Another option would be to eliminate the overhang and pull the support girder out to the edge then it might be ok to just use joist hangers as you would be simply supporting each end of the beam.

    Greg
    You must be telepathic because I came to the same conclusion last night....After thinking about it a bit more, and determining that I need to add joists every 12" to accommodate the composite decking support requirements on the existing deck, that I will make them run full length and then splice in the pieces for the shorter extensions. That way every other joist will run full length across the width of the deck, which should be adequate for load bearing and we can still keep the overhang.
    Lee Schierer - McKean, PA

    My advice, comments and suggestions are free, but it costs money to run the site. If you found something of value here please give a little something back by becoming a contributor! Contribute

  5. #5
    I can't read your dimensions but besides sistering every joist you may need to add vertical support. I think our local code restricts a cantilevered overhang to be not more than 36" before vertical support is required.

    When we expanded our deck our local building code required such support as well as a building permit and inspection.
    Mike Null

    St. Louis Laser, Inc.

    Trotec Speedy 300 Newing Hall 350 Hot Stamping
    Woodworking shop CLTT and Laser Sublimation Sand Carving Graphtec CE5000-60
    Evolis Card Printer
    CorelDraw X5 , Engravlab

  6. #6
    Quote Originally Posted by Mark Norman View Post
    I would pull the skirt off and sister the joists back to the girt
    Ditto...........
    If at first you don't succeed, look in the trash for the instructions.





  7. #7
    Quote Originally Posted by Mike Null View Post
    I can't read your dimensions but besides sistering every joist you may need to add vertical support. I think our local code restricts a cantilevered overhang to be not more than 36" before vertical support is required.

    When we expanded our deck our local building code required such support as well as a building permit and inspection.
    My overhangs are less than 25" and I have an added support under the new area with no span greater than 4'-6" on 2 x 8 joists on 12" centers.
    Lee Schierer - McKean, PA

    My advice, comments and suggestions are free, but it costs money to run the site. If you found something of value here please give a little something back by becoming a contributor! Contribute

  8. #8
    I sent you a PM. . .

    I live in the area, and do decks and such for a living. I wouldn't mind coming over and giving my opinion while I am in Mckean next week.

    A little off topic, but are there other local forum members? I would love to find out where everyone gets their lumber and such.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •