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  1. #1
    ozfreelancer is offline Apprentice (new member)
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    Default Fixing Joists over Bearers using Pryda Connectors

    Hello Experts,

    I have just started digging holes for my bearer supports. I have a question on "fixing the joist over the bearer". What sort of Pryda connector should I use - Unitie or Joist Strap or Triple Grip ? I am planning on Unitie. Further how many connectors should I use at each joint ? - 2 connectors at diagonally opposite corners ?

    Your help and comments are invaluable.

    Cheers
    Ranga

  2. #2
    SilentButDeadly's Avatar
    SilentButDeadly is offline Duck Fat - 2K club member
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    Unitie is fine. And yes use two each joint, diagonally opposed. Won't hurt to block the joists at every second bearer either.
    People don't ever seem to realise that doing what's right is no guarantee against misfortune

  3. #3
    ozfreelancer is offline Apprentice (new member)
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    Thank you so much. May I know what do you mean by "block the joists at every second bearer " as I don't understand this. How do I block the joists ? I still have a lot to learn...

    Cheers
    Ranga

  4. #4
    SilentButDeadly's Avatar
    SilentButDeadly is offline Duck Fat - 2K club member
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    Use the joist material to create a 'block' between the joists. This helps prevent the joists rolling over and makes the floor frame stiffer/stronger.
    People don't ever seem to realise that doing what's right is no guarantee against misfortune

  5. #5
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    Pulse is offline 1K Club Member
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    Default

    What's wrong with skew nailing?

  6. #6
    SilentButDeadly's Avatar
    SilentButDeadly is offline Duck Fat - 2K club member
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    Quote Originally Posted by Pulse View Post
    What's wrong with skew nailing?
    Nothing.

    But some people don't like it or haven't the technique to do it properly. That's where the Pryda product comes in...
    People don't ever seem to realise that doing what's right is no guarantee against misfortune

  7. #7
    prof_montoya is offline Senior Member
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    Default joist strip or skew nail

    Hey guys,

    Is there anything in BCA that prohibits skew nailing joist to bearers. I got that impression from my carpenter. I'm guessing skew nailing is faster and cheaper than joist straps and while not as strong, surely it is strong enough once you nail and glue the floor particleboards

    Thanks
    Carlos

  8. #8
    SilentButDeadly's Avatar
    SilentButDeadly is offline Duck Fat - 2K club member
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    Tis unlikely that the BCA says anything significant...but it can be 'significantly' interpreted by your inspector. Willing to take a punt?

    To mis-use the old adage from cycling..."Fast. Strong. Cheap. You can pick only two."
    People don't ever seem to realise that doing what's right is no guarantee against misfortune

  9. #9
    Bloss is offline Old Chippy - 4K Club Member
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    Quote Originally Posted by Pulse View Post
    What's wrong with skew nailing?
    Not as easy as it looks for a DIYer (and quite a few chippies too!). I have seen so many which are barely fixed - angle too shallow, angle to high, nails too short and so on. If a nail gun is available and the user is competent then can be a reasonable result, but same issues occur. Depends is the real answer - and also on whether a low deck (under 600mm or a high deck and so on - in this case we don't know).

    Get a copy of Allan Staines Decks & Pergolas book if you haven't already.
    Advice from me on this forum is general and for guidance based on information given by the member posing the question. Not to be used in place of professional advice from people appropriately qualified in the relevant field. All structural work must be approved and constructed to the BCA or other relevant standards by suitably licensed persons. The person doing the work and reading my advice accepts responsibility for ensuring the work done accords with the applicable law.

  10. #10
    intertd6 is offline 1K Club Member
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    Skew nails can hold down roof rafters in some situations, so they are ok for joists to bearers, just remember for exposed to the elements use hot dipped gal nails.
    regards inter

  11. #11
    Bloss is offline Old Chippy - 4K Club Member
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    mmm - did I mention minimum standards are not best practice?

    What's the point of a short cut or faster fixing for a DIY job? To save a few dollars? To save some time? For a deck that might be costing thousands and you hope will last 10, 15, 20 or more years?

    Sure minimum nominal requirements might allow two 75mm/3.05mm skew nails for each rafter (joist in this case), but for the minimal additional time and cost to do a job which will last and be stronger why skimp?

    I am no advocate of wasteful and unnecessary additional work or components, but not simply doing the minimum is just sensible quality construction IMO, but of course if OP or others are happy to do just the minimum then good luck with that.
    Advice from me on this forum is general and for guidance based on information given by the member posing the question. Not to be used in place of professional advice from people appropriately qualified in the relevant field. All structural work must be approved and constructed to the BCA or other relevant standards by suitably licensed persons. The person doing the work and reading my advice accepts responsibility for ensuring the work done accords with the applicable law.

  12. #12
    ringtail is offline 3K Club Member
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    All joists should be skew nailed over the bearer as a nominal (minimum) fixing. In addition 1 x triple grip should be used per crossing. Uni ties while ok are not as good as triple grips. Nails for skew nailing should be good old fashioned hot dipped jolts 75 x 3.15-predrilled, hand nailed and punched in hardwood. With pine gun nailing is fine if you're any good as Bloss said before. I always use hot dipped gun nails for everything inside and out. Sure they cost 3 x the price but its well worth it IMHO. The tie down is stipulated in AS1684, not the BCA. Clamp the joist to the bearer in the correct position, predrill and skew nail. On the opposite side to the nail head place the triple grip. Leave the clamp in place until you have finished all the nailing.

  13. #13
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    As ringtail and bloss have said, skew nail is the minimum requirements as per 1684. It all depends on your wind category if you need additional tie down/uplift. I always use a triplegrip for the sake of 0.50c and 5 minutes work. What the poster has forgotten to mention is if this is fixing to an intermediate bearer or end bearer here or even if its for a join over bearer.
    Also what is the span of the joist? you need to "block" every 1800mm width of joist, so if your deck is 3600mm you need a centre row continuous blocking across your deck.

  14. #14
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    Just to put a few references on this thread. All from AS 1684.2 (non cyclonic) 2006 (but appear no different in 2010 update).

    joists to bearers:

    picture-2.pngpicture-3.png

    Blocking:

    picture-4.png

    I think it is important to clarify what is personal opinion as to good practice and what the rules say.

    cheers
    Pulse

  15. #15
    intertd6 is offline 1K Club Member
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    I couldn't agree more with the above statement, if you were to use the best practice you would use the strongest most durable timber with the most corrosion resistant fixings & fasteners. generally the BCA or standard is the minimum best practice, after that the sky is the limit with how much time & money you want to inject into a project.
    regards inter

  16. #16
    prof_montoya is offline Senior Member
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    Default

    Hi guys,

    Thanks for the additional info/ discussion re attaching joist to bearers. Here is more info. Bearer and joists are both F17 hardwood. Location is internal floors (house extension). Can nail gun be used for skew nail in this situation (normal 75mm framing nails). Can I avoid hand nailing and pre drilling? Not sure I need to worry about wind loads in this situation.

    Cheers

    Carlos

  17. #17
    ringtail is offline 3K Club Member
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    Quote Originally Posted by prof_montoya View Post
    Hi guys,

    Thanks for the additional info/ discussion re attaching joist to bearers. Here is more info. Bearer and joists are both F17 hardwood. Location is internal floors (house extension). Can nail gun be used for skew nail in this situation (normal 75mm framing nails). Can I avoid hand nailing and pre drilling? Not sure I need to worry about wind loads in this situation.

    Cheers

    Carlos

    What type of F17 ? If its supa17 its Vic Ash and it takes a gun nail really well - provided you can shoot properly of course and your gun isn't a POS cheapy. If its something boney you could be in heaps of strife with a gun. If the gun nail doesn't go in all the way you wont stand much of a chance punching it in after - gun nails dont like being punched unless they are nearly all the way home.

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