# Forum Home Renovation Decking  Joining Bearers NOT on top of posts

## grcau

I'm building a deck around a pool - a total of 11.6m long.  The engineer has specified 6 posts and I have 4.2m bearer timber F17, 150x50.  Is it possible to join this timber NOT above the posts - if so, what is the best way to do it. 
Joining it at approx 4mm intervals means I use three boards - joining above the posts means I use 5 boards per bearer. 
I was thinking of but joining the timber and bolting a steel plate front and back.  While this will definitely provide enough strength, will the certifier have an issue with it?  Will it be safe?

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## Bedford

Welcome to the forum. 
I think the easiest way would be to use an extra stump, that way your joins can be directly above the stump. 
It will reduce the span, so the engineer should be happy with it, but when you make the join you need to end up with the bottom edge of each bearer sitting on the stump.

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## intertd6

It can be done, but cost wise it is cheaper to just get the right amount & length bearer to suit the job, the extra costs for not joining it over a bearer would be an engineered solution by the way of fish plates certified by an engineer or gang nail plates done by a truss manufacturer.
regards inter

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## ringtail

No. Your certifier will fail it. All joins in bearers shall occur over a support. AS1684

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## Savingdough

Can someone please confirm 100% that AS1684 will not allow plating??? My Qld certifier complained of unsupported joins in a removal home and said they needed to be 'plated or supported on stumps in accordance with AS1684'.  It sounds like he thought plating was an option, but I don't want it knocked back a second time when he reinspects and obviously I can't trust the builder to know or he wouldn't have left them unsupported to start with.  So I'd really appreciate it if someone could confirm what the standard says.

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## ringtail

AS1684.2 says     " Joints in bearers shall occur only over supports, with adequate bearing for both members ". 
Now that been said, it is possible to plate the two together, you just have to use a PFC and run it from post to post :Tongue:  :Biggrin: . Engineer will size the steel.

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## tissue

Just a query with this, if you joint the bearers above a support but have to put 2 x M12 bolts through the bearer at each support, can you just do a finger/dovetail joint and have a single bolt in each of the bearers (ie one each side of the joint)?

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## ringtail

Yep. Some choose to also pin the joint vertically but it depends on the spec / timber size / post set up

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## manofaus

why don't you just add another post per bearer... ie 7 supports, reduces your span to 1.93m, so you still can use three bearers.  
Guess it depends what is cheaper, a extra few posts, with supports (stirrups?) and footing or just the extra bearer material. Are you sure you can't get other lengths?

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## jkirky

To be blunt... 
You would spend far more time and energy attempting to achieve the inferior join without bearer support than actually installing an extra stump. 
Even with certifying aside, why would you go to all the effort of building a beautiful deck, only to jeopardize the structural integrity by taking a short cut. 
Yes short cuts can be taken in construction, but certainly not in structural applications or components. Ie, you dont NEED to use joist tape, you dont NEED to use stainless steel screws etc, but you certainly do NEED to ensure your subframe is adequately engineered. 
oNly my 2c- only trying to help!

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