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Thread: 6x6 Newel posts for porch stair guardrail: surface mount or embed in concrete?

  1. #1

    6x6 Newel posts for porch stair guardrail: surface mount or embed in concrete?

    I want to install stair guardrails in the steps of my front porch. I have five steps, so each handrail will be about 6 feet long. I want to install 2 newel posts at the bottom of the steps , top and bottom rails with balusters, which will be attached to existing upper posts on the porch. The steps (and porch floor) are concrete with a flagstone fascia

    I want to use 6x6 newel posts (to match the existing posts). Is pressure-treated appropriate? If so, can I surface-mount the newel post, or do I have to embed them in fresh concrete? In theory, the newel posts will be attached to the top/bottom rails and balusters, which themselves will be attached to existing posts -- so it's not completely free-standing. But I don't want the rails to wobble. On the other hand, I heard that embedding PT posts on concrete will eventually lead to rot due to the moisture trapped in the concrete.

    If surface-mount is good enough, are there other alternatives to PT? Some cellular PVC or polyurethane?

    Finally, if surface-mount, can I drill the concrete/stone fascia with a regular masonry drill and hammer drill? Or do I need to get one of those diamond drillbits and lubricate with water, etc?

    Thanks

  2. #2
    Join Date
    Sep 2009
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    Atlanta, GA
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    First -
    Long thread re: concrete and PT posts - search PT Concrete in Gen Woodoworking. Lotta emphatic opinions, too (but -mine is the correct answer - it is fine to do ).

    Full disclosure - I worked for the largest producer of PT lumber in the US for 15 years, and - painting PT lumber is not a good idea. You have to wait to let the lumber dry (I personally would not consider it for at least a year. Painting seals the wood, and as the PT dries, that moisture is going somewhere - and will take the paint off when it goes). You are better off, IMO, going to cedar or something like that if you are going to paint it.

    One exception - there is a product called "KDAT" which means kiln-dried AFTER treating. Hard to find, regular lumber yards usually don't understand it - will tell you "all the lumber is kiln dried", but that is BEFORE treating. If you can find KDAT, you have the best of both worlds.

    Second - google post anchor - you will find a bunch of different galvanized brackets to anchor the posts - prolly at the big box near you. You could install the post, then trim it out with wood to hide the metal bracket.

    Last - regular masonry bit and hammer drill fine for concrete - not sure what type of stone fascia you have - not much experience there
    Once more unto the breach, dear friends, once more;
    Or close the wall up with our English dead!

  3. #3
    If you want to paint them, use cedar. You can usually find rough or smooth 6x6's.
    You can use brackets, or notch the posts and glue and screw (tapcons) them to the front (riser).

  4. #4
    Join Date
    Jul 2007
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    Instead of embedding them in concrete, embed a 2" round pipe (or whatever diameter is handy) in the concrete and cut a mortise in the post to accept the pipe, and slip the post over the top. Then place a moisture barrier between the post and the concrete, and you won't need pressure treated if you plan to keep it painted. This allows you to replace the post eventually without busting up the concrete, and also prevents ground contact.

  5. #5
    I have either bolted to the side of the stair stringer or embeded in concrete. Bolting to the side is easier, concrete provides less play.
    Jeff Sudmeier

    "It's not the quality of the tool being used, it's the skills of the craftsman using the tool that really matter. Unfortunately, I don't have high quality in either"

  6. #6
    +1 on the pipe idea

    I am a fan of using concrete form pins 1" or 7/8" by 2' imbedded in concrete

    just drill a hole in post and glue...

  7. #7
    Look at the Titan Post Anchor, it is made for surface mouinting a post to any surface.

    http://www.ideas-for-deck-designs.co...st-anchor.html

  8. #8

    surface mount

    I have had good luck with the surface mount brackets. Sealing a post in concrete just causes rebuilding problems when it eventually rots away. (treated or not). The 2 inch pipe sounds like a good idea also. I have done similar things with re-bar.

  9. #9
    Thanks for your replies. For a number of reasons, I have decided to surface-mount the posts. I am going to drill the existing concrete and stone fascia, use epoxy, and push an all-threated 5/8 bolt, leaving about an inch exposed to insert a ABU66Z simpson strong-tie post anchor (galvanized steel), then attach the post. I am planning to use 6-inch bolts.

    Question: which bolt to use? I could use an all-stainless-steel (316 grade, non-magnetized) bolt, but they are not easily available and are pricey (and might have to buy a 3foot online and cut).

    I could use a stainless-steel-PLATED bolt (magnetized), which are more readily available in 1-foot lengths, but I am afraid they may rust.

    I can buy hot dipped galvanized bolts (like this one)
    http://www.amazon.com/Galvanized-Ult...026362&sr=1-17
    but I am afraid they may rust or not be appropriate for the job.

    Or I can buy a J-bolt, 8-inch, hot dipped galvanized, and cut the lower part of the "J" (as this is not fresh concrete). But I am afraid it may rust and not hold as firm, as it is not all-threated.

    Am I worrying too much about rust? My instinct tells me that a hot dipped galvanized should be enough, but I am open to the 316 SS if needed...

    Thanks

    Thanks

  10. #10
    Join Date
    Sep 2009
    Location
    Atlanta, GA
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    3,419
    Quote Originally Posted by Carlos Arteta View Post
    My instinct tells me that a hot dipped galvanized should be enough, but I am open to the 316 SS if needed...
    This is what I would use. Go with your instincts. This one will outlive you.
    Once more unto the breach, dear friends, once more;
    Or close the wall up with our English dead!

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