# Forum Home Renovation Structural Renovation  Structural Ply Bracing Installation Question

## johnstonfencing

Hello All, 
When installing the ply bracing around window or door openings, do I need to put the bracing above (or below if window not to floor) the opening over lintel?
or does the sheets just go either side flush with sides of openings? 
Hope the above makes sense! 
Cheers 
Craig

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## sol381

ply bracing goes form top of ribbon plate to floor.. DO NOT cut ply bracing.. it shouldnt go around doors or windows.. there should be enough open walls to put it.. Just follow whats set out on the plans..

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## pharmaboy2

> Hello All, 
> When installing the ply bracing around window or door openings, do I need to put the bracing above (or below if window not to floor) the opening over lintel?
> or does the sheets just go either side flush with sides of openings? 
> Hope the above makes sense! 
> Cheers 
> Craig

  Whats on the plans? 
usually, it's single sheets on the corners from top plate to bottom plate with 100mm between nailings (or something like that)
thats done for both tie down and bracing in one, but depends a lot on building design 
its not uncommon to sheath the whole house in brace though (including around openings) in order to give a consistant finish all round for claddings and provides air tightness to the structure . 
if it weatherboard type claddings, I'd install the extra ply so you don't have to pack out the weatherboards, and installing building paper is easier.  This of course would never be done on a project home......

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## pharmaboy2

> ply bracing goes form top of ribbon plate to floor.. DO NOT cut ply bracing.. it shouldnt go around doors or windows.. there should be enough open walls to put it.. Just follow whats set out on the plans..

  What is wrong with cutting plywood bracing? 
You can join over noggings, in fact in plenty of building designs you have no choice to join because of sheet sizes 
anyway, all you ever needed to know about ply bracing,...........  http://www.ezyhomes.com.au/pdf/tech/...%20Bracing.pdf   :Wink:

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## sol381

im not sure we are on the same page..how high are your walls..unless your entire house is full of windows or doors i dont know why you would use ply bracing across an opening.. most are  on corners.. if you follow the detail set out on your plans you should be ok..if you have a plan of your house showing the bracing that would help.. 
cutting ply bracing defeats the purpose of it.every metre of bracing equates to certain kn force and you need all of the bracing to achieve the desired result.. you can cut small hole in it to accomodate powerpoints but cutting it reduces its strength .. you start cutting it and it will most certainly not get it passed by a certifier..

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## phild01

Not following the don't cut argument.  I just apply braceboard as it fits the frame. Will be areas where it has to be cut, but important that nail type and spacing is to spec and the cut sheets have full perimeter anchorage, ie the sheets don't meet in the midst between framing members.

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## r3nov8or

If you have a 900 space between windows it won't matter if you use 1200 ply cut around a window or 900 ply not cut. It will still contribute 900mm of bracing. If cladding walls I also install ply across the whole wall to make it easier later.

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## johnstonfencing

Thanks for your replies. 
On the plans it requires sheet bracing on two external walls due to several windows and a bifold door not allowing metal bracing.  My main query was if it was a requirement to put the board above/below openings! But as some of you have suggested doing so will help with cladding later on! 
Cheers

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## Snipper

I put the ply on wherever it's stated and nail over window openings,  pack other studs if clad.  cut out windows later when nailed off with a recipro. Usually need to put small studs between window trimmers to pick up the edge of the sheet.  Nails 50mm centres on horizontal members, bottom plate, top or rim plate and noggins.  Nails 100mm centres on the studs.  I also measure and chalk line the ply for the studs before fitting for a nice neat job without nails coming through the inside.

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## johnstonfencing

Hello again, 
Quick question. 
Is it a requirement to put strap tie downs top and bottom over studs when using ply sheet bracing?
 As is required for metal D type! 
Cheers

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## intertd6

Yes, the two are separate structural features.
inter

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## sol381

no its not... the ply bracing ties the top and bottom plates together...you need to tie the bottom plate to the ground with dynabolts or booker rod tho.. within 100mm from outside studs..

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## johnstonfencing

Thanks for the replies. 
I did read in AS1684 (bracing section) that "no other rods or straps required between top or bottom plate" 
Can I presume this to mean no to my question? 
Cheers

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## r3nov8or

> Thanks for the replies. 
> I did read in AS1684 (bracing section) that "no other rods or straps required between top or bottom plate" 
> Can I presume this to mean no to my question? 
> Cheers

   What actual method per AS1684 are you using? i.e. state the clause

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## intertd6

> no its not... the ply bracing ties the top and bottom plates together...you need to tie the bottom plate to the ground with dynabolts or booker rod tho.. within 100mm from outside studs..

  a frayed knot, the stud tie down details for uplift are separate to the the bracing details, the minimum stud tie down in a load bearing wall is every second stud,  the stud tie down for the sheet & strap bracing is separate structural element from the former & is present in the wall anyway because of the tie down requirement. http://www.timber.net.au/images/down...4/AS1684_3.pdf
inter

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## pharmaboy2

> a frayed knot, the stud tie down details for uplift are separate to the the bracing details, the minimum stud tie down in a load bearing wall is every second stud,  the stud tie down for the sheet & strap bracing is separate structural element from the former & is present in the wall anyway because of the tie down requirement. http://www.timber.net.au/images/down...4/AS1684_3.pdf
> inter

  i don't think they are talking about a total tie down design, but just those points between the top plate to stud and bottom plate to stud.  These 2 connection points in anything under 16Kn are satisfied by bracing ply nailings that cover the stud and the bottom and top plates.  Page 17 of the link from plywood association above. 
it would not replace something like a 12mm threaded rod from roof to subfloor I wouldn't imagine, but certainly replaces those small strap connections of plate to stud.   Ply in tension is very strong, added to that orders of magnitude nailings that are generally the weak points in design. 
so ply doesn't replace the entire tie down requirements, but it does replace individual connection points as appropriate.

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## intertd6

> i don't think they are talking about a total tie down design, but just those points between the top plate to stud and bottom plate to stud.  These 2 connection points in anything under 16Kn are satisfied by bracing ply nailings that cover the stud and the bottom and top plates.  Page 17 of the link from plywood association above. 
> it would not replace something like a 12mm threaded rod from roof to subfloor I wouldn't imagine, but certainly replaces those small strap connections of plate to stud.   Ply in tension is very strong, added to that orders of magnitude nailings that are generally the weak points in design. 
> so ply doesn't replace the entire tie down requirements, but it does replace individual connection points as appropriate.

  the compulsory tie down points (straps) are already designed into the frame & are so close together it makes the consideration of not having them there for sheet bracing a non argument.
inter

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## Moondog55

The way I read the tables and the pages about ply bracing I would say that the ply bracing is adequate as stated on Pp17 in the linked document and no need to use separate ties from top plate to stud, bottom plate to stud if using the strongest rated bracing method ie Glue plus nails, tie down of rafter to top plate and bottom plate to bearer and then bearer to ground is mentioned of being then the greatest concern
It clearly states that every 900mm ply bracing panel is the equivalent of a 12mm threaded rod top to bottom

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## jimfish

Our building surveyor doesn't require us to fit stud ties where we install bracing ply

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