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  1. #1
    Join Date
    Jun 2004
    Location
    Friday Harbor, San Juan Island, Washington
    Posts
    13,029

    Default Deck stair newel posts... anchoring?

    Just about to frame up two sets of stairs from a deck. Both descend to grade. The stairs are fairly typical: 2x12 stringers, ipe treads and risers. The deck posts are 4x4 PT wrapped in 1x cedar. I'm thinking about how I'm going to anchor the newel posts at the bottom of each stair solidly. I do not want to cast the posts right into concrete like fence posts, because they'll rot out sooner than I can stand to replace them. Here are three ideas I had:

    1) Pour a small grade beam at the bottom of each stair, and embed a Simpson CBQ column base for each 4x4. Anchor the posts in the CBQs, anchor the outside stringers to the posts, and wrap the posts. The posts and grade beam would form a sort of 'U' shape and the hardware would give the posts a lot of stiffness. I know that Simpson says 'not for non-top-supported applications'

    2) Solid block with 4x6 between the stringers at the bottom, and then run all-thread horizontally all the way thru the posts with a nut and washer on each end. This would let me compress the whole assembly quite a bit and lock the posts in.

    3) Use someone else's method. How do you typically do this?

  2. #2
    Join Date
    Jul 2004
    Posts
    664

    Default Re: Deck stair newel posts... anchoring?

    David:
    I guess most decks are 6-7 risers max...if higher from grade we usually like to break them with a landing or turn or two.

    Typically, we like a closed stringer (2X12 finish species with notched treated) and we install solid bridging between and stringers at 16" OC.

    We notch the newels into the carriage and use carriage bolts for the newel to stringer connection. With softwoods especially (redwood, cedar) we can play with the ratchet to get things perfectly plumb. The balustrade contacting the outside of the stair carraige is fastened to the stringer from the inside before the treads are installed.

    We screw and plug.

    This is a pretty quick and dirty method that has worked for us.

    Once the treads and risers are in place, and the carriage bolts are cranked, the assembly is about as stiff as you would want it to be.

    Henry

  3. #3

    Default Re: Deck stair newel posts... anchoring?

    David,

    All our deck stairs are 2x12 stringers 12" o.c. with a single 2x6 notched into the bottom of the stringers and another 2x6 notched into the back of the top treads. This makes a single stair assemably which allows us to mount the newel post to the inside of the stringer with 2- 1/2"x6" bolts. We never have notched any posts and now every where you look the recommendations are not to notch any railing post. We are from the Chicago area and have seen what can happen with 3 or 4 story decks that have notched posts. Do not notch any railing posts.

    George
    Jerzy Decks

  4. #4
    Join Date
    Jul 2004
    Posts
    664

    Default Re: Deck stair newel posts... anchoring?

    Quote Originally Posted by gjustynski
    We are from the Chicago area and have seen what can happen with 3 or 4 story decks that have notched posts.
    George:
    Thanks for the heads up. I guess there should be more of a concern in rail resistance between 3 1/2" by 3 1/2" and 3 1/2" by 2" (notch) when you are looking at a 30' drop (even in Chicago).

    The original post and question was about connections a little closer to grade level (smile).
    Henry

  5. #5
    Join Date
    Jun 2004
    Location
    Friday Harbor, San Juan Island, Washington
    Posts
    13,029

    Default Re: Deck stair newel posts... anchoring?

    The last issue of JLC had an article about deck post connections. I think it had some photos of the Chicago thing too. My detail on the deck does not have notched posts. The joists are 2x8 and the posts are 4x4 attached inside the framing, not outside, due to the trim details I'm doing. Everything is bolted and blocked and plenty strong, and there aren't even railings tying it together yet.

    The only place I am concerned is at the bottom of the stairs, and it's not really as much of a safety issue as an issue of 'feel'--I want the posts to feel rigid. I'm leaning towards casting the CBQ's in the concrete and seeing how that works.

    Someone on the FHB forum detailed a method of embedding a threaded rod in the concrete and then using a hollow post with solid blocking near the top, so that the rod can be cinched down inside the post.

  6. #6
    Join Date
    Jun 2004
    Location
    Chicago
    Posts
    3,599

    Default Re: Deck stair newel posts... anchoring?

    After the porch collapse here in Chicago two years ago that killed about a dozen young people (I'm sure you've all heard about this), the City put together a comprehensive manual explaining specifically how to construct a porch or deck that will meet the 100 lbs/sq. ft. load requirement.

    It includes model plans and a multitude of required construction details and also shows many details that are commonly used, but prohibited.

    In case anyone might find it useful, you can find it here:

    http://www.cityofchicago.org/dcap/Porch_Welcome.html

  7. #7
    Join Date
    Jul 2004
    Posts
    664

    Default Re: Deck stair newel posts... anchoring?

    My apologies if my post seemed to lack any sensitivity. I had not heard about this tragic accident.
    Henry

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