# Forum Home Renovation Structural Renovation  Joining structural posts

## KSG

We are looking at raising our Queenslander in Brisbane about 1 metre so it is legal height underneath.  We have an existing deck out back that will eventually be replaced with a larger deck but in the short-term we want to keep the existing deck in place. 
Is it possible to extend the existing structural posts and if so what is the best way to go about this?  Or should I just replace the posts completely with a single length of structural timber?  Picture of one of the existing posts below.

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## OBBob

I went down the path of trying to extend a gate post with a bolted Lap Joint because it was concreted in the ground and it seemed the easier option. In reality (as is often the case) it was a PITA and I did a lot of work and ended up replacing the whole post anyway.  
Those are just bolted to a styrip, so I'd just replace them I think. Also, structural is another significant step from a gate post.

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## Marc

I think the question is more ... is it worth joining the post as opposed to replacing them.
Of course you can joint the post and extend them using a scarf joint but there is a considerable amount of work involved. Also the logistics of doing such job would be that you lift the house, unbolt all the post, join one meter of post to each using a jig to make the joint properly and bolt all back on. 
Not worth the trouble if you ask me, but I am not paying for the post so it's easy for me to say.  :Smilie:  
How long can you keep the house on props? it would take some time to make all those joints, unbolt bolt back on, secure to stirrup, replace those that are rusted or in the wrong place ... etc etc

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## Marc

That formula for the scarf joint is of course wrong if it reads 2.5 divided by 3.
if it is a weird way to say 2.5 up to 3 times S then it may be OK. 
 S1 needs to be Sx3 or even Sx3.5

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## r3nov8or

of all the google image results for 'scarf joint' I haven't found a post yet. All beams, bearers and rafters etc

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## KSG

So basically more hassle than it is worth to try and extend post.

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## Marc



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## Marc

> So basically more hassle than it is worth to try and extend post.

  Well ... I have never lifted a house one meter. 
I suppose that it is not a cheap exercise but I don't really know. 
So if it is worth saving the money for the X number of post you need is not something I could answer. How much money is it in the overall exercise? 1%, 5%, 10%, 50% ?
Like I said, it is possible with some work. It will hold you up because you can not prepare it beforehand, but then again that may not be a problem.
Furthermore I don't even know if it is legal, that is, something the certifier will approve. I only know it is structurally sound if done at an angle like in the first picture.
I use to own an adobe house that was 100 years old, on stilts and every single post had a scarf joint. 
Where is Ringtail? he lives in the levitating houses region  :Smilie:

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## ringtail

Yep do it. Easy as. Straight butt join of the posts with 100 x10 flat bar each side 400 mm long and 4xM12 bolts - 2 above the join and 2 below. Not going anywhere. Don't over think it since it's temporary. A simple half lap join is more than ample too

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## KSG

> Yep do it. Easy as. Straight butt join of the posts with 100 x10 flat bar each side 400 mm long and 4xM12 bolts - 2 above the join and 2 below. Not going anywhere. Don't over think it since it's temporary. A simple half lap join is more than ample too

  Cheers ringtail.  I'll do just that.

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## OBBob

If I went to the trouble of a scarf joint like that it wouldn't be temporary... it'd be on display!   :Biggrin:

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## Marc

What do you mean by temporary?

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## KSG

> What do you mean by temporary?

  I'm going to replace the deck eventually, in the next 12-18 months, so what I want to do will just be a temporary fix until this takes place.

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## KSG

> If I went to the trouble of a scarf joint like that it wouldn't be temporary... it'd be on display!

  Maybe I'll frame one afterwards  :Biggrin:

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## OBBob

I'm sure there's plenty on here that have those skills but with normal hand tools those sorts of joints are harder than they look.

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## ringtail

> Cheers ringtail.  I'll do just that.

  It won't look too pretty but it's fit for purpose. Make sure you position the bolts so they don't catch anyone walking past.

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## intertd6

> We are looking at raising our Queenslander in Brisbane about 1 metre so it is legal height underneath.  We have an existing deck out back that will eventually be replaced with a larger deck but in the short-term we want to keep the existing deck in place. 
> Is it possible to extend the existing structural posts and if so what is the best way to go about this?  Or should I just replace the posts completely with a single length of structural timber?  Picture of one of the existing posts below.

  If you alone are doing it without an engineers certificate & sign off, forget it. If you can get an engineer to put their monica on it, it will cost you dearly.
inter

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## ringtail

Of course, do it at your own risk. An engineer will charge about $200 bucks if you want to cover your rrse.

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## Marc

Temporary means you are doing this post extending only for the deck?  What are you doing for the house post? 
As far as patching a post cut square and aided with two steel plates sure it will work too. Even better if you use unequal angle 100x75x6 ... no need for 10mm plate.

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## intertd6

> Of course, do it at your own risk. An engineer will charge about $200 bucks if you want to cover your rrse.

  in my experience something like this would cost thousands, because of the high risk situation of a deck/balcony they would go overboard in design then want to inspect every joint, a principal CPE charges anywhere between $200 to $400 an hour for their services & it doesn't take long to eat up a couple of K, it would be just easier & safer in the long run to just replace the posts & add some bracing as per the standard.
inter

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## ringtail

Some engineers have a degree of common sense and look at something like this and know that unless paddle pop sticks are used, just about any solution carried out by someone competent will be fit for purpose.

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## OBBob

> Some engineers have a degree of common sense...

  ... or really good PI insurance.   :Tongue:

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## ringtail

> Temporary means you are doing this post extending only for the deck?  What are you doing for the house post? 
> As far as patching a post cut square and aided with two steel plates sure it will work too. Even better if you use unequal angle 100x75x6 ... no need for 10mm plate.

  Could do that too as long as the angles were on diagonally opposite corners so the 75's weren't overlapping. Of course the posts would need to harrised to suit the internal radius of the angle. 10 mm flat bar is easier and way neater IMO. 
The house posts would be done in steel I'm assuming and when the deck extension/reworking gets done then new deck posts go in.

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## ringtail

> ... or really good PI insurance.

  Mandatory these days regardless

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## Marc

> Could do that too as long as the angles were on diagonally opposite corners so the 75's weren't overlapping. Of course the posts would need to harrised to suit the internal radius of the angle. 10 mm flat bar is easier and way neater IMO. 
> The house posts would be done in steel I'm assuming and when the deck extension/reworking gets done then new deck posts go in.

  Yes, lots of mucking around but you gain a lot of room. 
I like the scarf joint. Done heaps of them using a jig for a circular saw. Need to finish one of the cuts by hand though.
I wonder if an engineer would sing it off? They have probably never seen one done.

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## intertd6

> Yes, lots of mucking around but you gain a lot of room. 
> I like the scarf joint. Done heaps of them using a jig for a circular saw. Need to finish one of the cuts by hand though.
> I wonder if an engineer would sing it off? They have probably never seen one done.

   That's their business & bread & butter to certify stuff like this, that's why they accept the liability if something fails & charge accordingly.
inter

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## ringtail

So charging accordingly would be $10 for steel plate fishplates as there is zero chance of failure.

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## intertd6

> So charging accordingly would be $10 for steel plate fishplates as there is zero chance of failure.

   If only it worked that way. It used to, but unfortunately not anymore.
you really should sit in on a court case where a barrister tears apart a half educated laymans guess that has gone belly up, it is a real eye opener & I don't know anybody has the full use of their faculties that would put themselves into that position.
inter

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## Marc

Your honour, a scarfed post can take the same load as a whole post.
- Sure, yet if all the post had been full and not patched up they would have resisted the shock from the car that came off the road and plunged in the house making it fall on the defendant.
We live in interesting times.  :Smilie:

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## ringtail

> If only it worked that way. It used to, but unfortunately not anymore.
> you really should sit in on a court case where a barrister tears apart a half educated laymans guess that has gone belly up, it is a real eye opener & I don't know anybody has the full use of their faculties that would put themselves into that position.
> inter

  It's a good thing it's not a half educated layman's guess then isn't it.

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## intertd6

> It's a good thing it's not a half educated layman's guess then isn't it.

  Unless you have CPE after your title & could prove your limit state design is adequate in court, it's a guess however highly you rate yourself.
but let's look how ridiculous your argument is, you can't even repair more than 1 in 5 common studs in a wall that have been cut & crippled, then made good with an approved & engineered repair & you are proposing to repair all the posts on a high deck with no engineered or approved method!!!! WTF 
inter

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## ringtail

> Unless you have CPE after your title & could prove your limit state design is adequate in court, it's a guess however highly you rate yourself.
> but let's look how ridiculous your argument is, you can't even repair more than 1 in 5 common studs in a wall that have been cut & crippled, then made good with an approved & engineered repair & you are proposing to repair all the posts on a high deck with no engineered or approved method!!!! WTF 
> inter

  Post removed - edited. Inter is not involved in the building industry AFAIK so his comments of the past, present and future are moot. Until he provides evidence of his qualifications by way of a business name and website and posts photos of his work for critique then I assume he works at Kmart. Same goes for any other unqualified haters out there. Put up or shut up. Enough is enough. Get pictures of your "work" up here for evaluation by real tradespeople and we shall see who can walk the walk.

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## OBBob

Guy's... take it easy - I like the forum to have a warm fuzzy vibe and I'm not feelin' it.   :Biggrin:

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## r3nov8or

> Guy's... take it easy - I like the forum to have a warm fuzzy vibe and I'm not feelin' it.

  Coffee and muffins

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## OBBob

> Coffee and muffins

  Don't mention the C word!   :Biggrin:

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## intertd6

> What on earth are you rabbiting on about now .

  You poor dear! Your idea is stupid, get over it!
inter

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## intertd6

> Post removed - edited. Inter is not involved in the building industry AFAIK so his comments of the past, present and future are moot. Until he provides evidence of his qualifications by way of a business name and website and posts photos of his work for critique then I assume he works at Kmart. Same goes for any other unqualified haters out there. Put up or shut up. Enough is enough. Get pictures of your "work" up here for evaluation by real tradespeople and we shall see who can walk the walk.

   Like to bet your house & all you own on it?
inter

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## ringtail

Nope. Just give the details. Put up or shut up. Totally up to you Mr. Kmart

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## ringtail

> You poor dear! Your idea is stupid, get over it!
> inter

  Explain, in intricate detail why my idea is "stupid".

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## intertd6

> Nope. Just give the details. Put up or shut up. Totally up to you Mr. Kmart

  put up or shut up then, I'd put it all on the line & it would be the easiest & quickest money I'd ever made, it might take 2 minutes tops. 
inter

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## ringtail

Ok, so you're not willing to give your business name, website, qualifications or post photos of your alleged work. So it's safe for me to assume that you work at Kmart or have something to hide. Which is it ?

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## ringtail

> Explain, in intricate detail why my idea is "stupid".

  Still waiting Mr.Kmart

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## intertd6

> Explain, in intricate detail why my idea is "stupid".

  i already have, but you don't seem to have the ability absorb anything logical about cost, risk or the scope of what a carpenter, builder or homeowner is safely allowed to do in this country.
inter

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## intertd6

> Ok, so you're not willing to give your business name, website, qualifications or post photos of your alleged work. So it's safe for me to assume that you work at Kmart or have something to hide. Which is it ?

   Of course I am, your just not game to lose it all getting that information.
inter

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## ringtail

Why would I risk anything ? I have nothing to hide. My work is all over this and many other forums. Plenty of us have our businesses and work on here. Metrix, PG, Jimfish, JimJ and others ( sorry if I forgot other regulars) My website is freely available for all to see yet we seem to have a few on here that are unwilling, for reasons unknown, to make their professions known. I don't get it. What are you guys afraid of ? Surely you're not ashamed of what you do for a living so just spill the bloody beans. Of course, if you're not willing to give evidence of your qualifications then you speak here with zero authority.

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## intertd6

Unless you grow a set, you're going to have to get used to some bloke who may possibly work at Kmart, displaying a little more knowledge & experience for which that the position calls for.
inter

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## ringtail

Alrighty then. Kmart it is. Not that there is anything wrong with working at Kmart. You might be like Will Hunting doing a menial job to mask your brilliance.  It seems we will never know.

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## ringtail

> Explain, in intricate detail why my idea is "stupid".

  Still waiting for this.  
Clean up aisle 5.

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## intertd6

Keep the stupid ideas coming, even the schoolies on work experience at Kmart could join the dots & get a laugh out of them, unless a party of them happened to be on top of said posts.
inter

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## ringtail

Well, come on then. Schoolies on work experience sounds like an apt description for you so you should have no problem. Stop being a flog and explain your statement. The BS from you and others stops right now. If you are not capable of answering just say so. I certainly can't think any less of you.

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## intertd6

> Well, come on then. Schoolies on work experience sounds like an apt description for you so you should have no problem. Stop being a flog and explain your statement. The BS from you and others stops right now. If you are not capable of answering just say so. I certainly can't think any less of you.

  Your the one giving out stupid BS advice, 
show us where you were trained in joining structural posts in the said location as you suggest;
show us where your method is approved for use in this country without other engineering approval using the relevant standards;
show us where you have calculated the resistance to all the loads & forces with safety factors included;
show us you're not making a unfounded wanker guess.
Inter

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## OBBob

Guess the mods are all on holiday. It's gone a bit beyond a healthy debate guys. Agree to disagree and move on.

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## Marc

Come on Inter, let it go, be the bigger person.
Ringtail, sometimes you have to accept that others may actually be right... even on the subject of coffee ...  :Smilie:

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## SabreOne

> Guess the mods are all on holiday. It's gone a bit beyond a healthy debate guys. Agree to disagree and move on.

  I'm surprised it's been allowed to go on so long. 
And how has this help the OP ?   :Biggrin:

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## KSG

> I'm surprised it's been allowed to go on so long. 
> And how has this help the OP ?

  It has been keeping me entertained  :Biggrin:

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## intertd6

Imagine the entertainment over at the whirlpool site when the silly ideas start flying about, this is more than enough for me just here.
inter

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## ringtail

KSG, the advice is fine but do whatever you want. Inter has never held a hammer before AFAIK so if you want to take his advice over mine that's fine. I hold qualifications in structural steel fabrication, carpentry and mechanical engineering. Inter has zero qualifiactions AFAIK so please yourself. The method I mentioned can be engineered for $200. Up to you.

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## intertd6

> KSG, the advice is fine but do whatever you want. Inter has never held a hammer before AFAIK so if you want to take his advice over mine that's fine. I hold qualifications in structural steel fabrication, carpentry and mechanical engineering. Inter has zero qualifiactions AFAIK so please yourself. The method I mentioned can be engineered for $200. Up to you.

  so we can take that as a carpenter, a welder/ boilermaker & a mechanic, some very handy skills to have in the building industry & can be put to good use once the appropriate instructions are issued by those qualified to make them.
inter

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## ringtail

Inter, I never said my method should not be engineered. Quite the opposite. The engineering should be done if for no other reason than to get that pesky form 15 that covers everyone's rrse. I did say that the method is more than adequate for joining two pieces of structural post together and that engineering costs would be minimal and I totally stand by that - without seeing the job of course. Looking at the photos KSG has provided with rotting posts in stirrups with 1 bolt I would say that joining a new post (in the stirrup with 2 new bolts) to a freshly cut section of the original post using my method would be a vast improvement on what is currently there. Having said that, I've seen decks supported by acro props for 6 years with no problem so given that an acro prop is fully engineered maybe KSG should go that way. It's only a temp job anyway and long term rental is cheap. A bit of fencing wire to hold them in position, all good as they're engineered.  :Tongue:

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## intertd6

> Inter, I never said my method should not be engineered. Quite the opposite. The engineering should be done if for no other reason than to get that pesky form 15 that covers everyone's rrse. I did say that the method is more than adequate for joining two pieces of structural post together and that engineering costs would be minimal and I totally stand by that - without seeing the job of course. Looking at the photos KSG has provided with rotting posts in stirrups with 1 bolt I would say that joining a new post (in the stirrup with 2 new bolts) to a freshly cut section of the original post using my method would be a vast improvement on what is currently there. Having said that, I've seen decks supported by acro props for 6 years with no problem so given that an acro prop is fully engineered maybe KSG should go that way. It's only a temp job anyway and long term rental is cheap. A bit of fencing wire to hold them in position, all good as they're engineered.

  Your advice in posts #9 & #16 didn't mention anything about engineering certification until it was raised as being a necessity, which goes without saying, it is. I don't know about QLD but here even formwork over a certain height or area has to be certified by an engineer.
inter

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## ringtail

> Your advice in posts #9 & #16 didn't mention anything about engineering certification until it was raised as being a necessity, which goes without saying, it is. 
> inter

  Well, it is only if one doesn't want to take the risk. It's all about risk and insurance. Plenty of people have no house insurance at all probably because they can't afford it but people out there also accept the risk. Heaps of illegal renovators accept the risk too. Either way, it's a risk I would certainly take on my own house as it's temporary. I don't know why engineers are so expensive down there. My entire renno was done for $600 and that included removing 3 walls, 2 decks, and reframing the whole front of the house with insitu welded RHS. Like I said earlier, if it's a common sense modification they don't bat an eyelid. I designed everything and submitted it and the only query I got from the engineer was why are you making so strong. Every time, without fail I get " you don't need to use 16 mm bolts, 10 mm will do" or "that beam is way too large" or " that hole is too deep, you'll spend a fortune on concrete" or " 6 mm plate is more than enough, why do you want to use 10 mm? I've never been accused of under building anything or even sailing close to the edge of structural integrity in anything I build.

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## OBBob

> It has been keeping me entertained

  
Have you finished this job yet? Something tells me this could be debated long after the temporary and permanent solutions are complete.  :Smilie:

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## intertd6

> Well, it is only if one doesn't want to take the risk. It's all about risk and insurance. Plenty of people have no house insurance at all probably because they can't afford it but people out there also accept the risk. Heaps of illegal renovators accept the risk too. Either way, it's a risk I would certainly take on my own house as it's temporary. I don't know why engineers are so expensive down there. My entire renno was done for $600 and that included removing 3 walls, 2 decks, and reframing the whole front of the house with insitu welded RHS. Like I said earlier, if it's a common sense modification they don't bat an eyelid. I designed everything and submitted it and the only query I got from the engineer was why are you making so strong. Every time, without fail I get " you don't need to use 16 mm bolts, 10 mm will do" or "that beam is way too large" or " that hole is too deep, you'll spend a fortune on concrete" or " 6 mm plate is more than enough, why do you want to use 10 mm? I've never been accused of under building anything or even sailing close to the edge of structural integrity in anything I build.

  It seems like the opposite of " penny wise & pound foolish " when it comes to situations of critical importance.
A quote is the only real way of finding out the engineering rates or costs, but from from my experience in dealing with them, sometimes on a weekly basis & sometimes dealing with what appeared to be excessive costs, they don't come cheap & to think that an engineer would do a couple of site visits, calculations, drawings & certification for $200 is a bit fanciful.
The ones I know would advise to replace the posts as their costs would outweigh any timber savings.
inter

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## ringtail

Any engineer with any experience can look at something like this and say yes or no on the spot. No need for calulations and drawings. They know the forces at play off the top of their heads. This is not bridge or skyscraper building. The forces in domestic construction are tiny as is evident by the number of ancient houses on poor foundations or no foundations with no tie down, undersized members, termited structural members etc..still standing or leaning quite happily, enduring all that nature can deliver. 1 site visit and a signature on a form 15. Done.

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## ringtail

Just did a few figures. Assuming the "legal height" that KSG is after is 2.7 rather than 2.4, the cost to replace the whole post with F17 100x100 appearance grade and new bolts top and bottom would be about $110 materials only. Could be cheaper by using cheaper posts. 
To replace a section, allowing 200 mm to be chopped off the rotten bottom and adding a 1.2 mt section with the steel and 6 new bolts is $85 materials only.  
So adding engineering and it's a no brainer really. Replace the whole post. No approvals or inspections required. Delivery and acro prop hire would apply in both cases. New posts could maybe be repurposed as handrail posts for the new deck or even used as the new deck posts if the block is level

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## OBBob

> So adding engineering and it's a no brainer really. Replace the whole post.

  Well, I think even the OP worked out back at Post #06! But you guy's feel free to keep debating the side-point.  :Smilie:

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## Marc

Can't the post be welded?
They do sell welding rods for timber, we used to send the apprentice to buy them all the time.

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## ringtail

Since when do dentists have apprentices ?  :Tongue:

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## ringtail

> Well, I think even the OP worked out back at Post #06! But you guy's feel free to keep debating the side-point.

  Well, the side point was the point of debate. The cost never came into it really.

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## KSG

Thanks all.  All advice considered and taken on board.  I'll let you know what I decide to do when the time comes to complete the job.

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## METRIX

> Since when do dentists have apprentices ?

  Info on Dental Apprenticeship Programs

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## ringtail

USA site

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## METRIX

> USA site

  Only the best for Marc, he flies his private jet over there on a weekly basis.

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## ringtail

So true. Negatively geared air travel, of course.  :Wink:

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## METRIX

> So true. Negatively geared air travel, of course.

  Of course, his lady friend below tags along, there is something strangely familiar about these two !!

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## SilentButDeadly

Yep. They're both self operated Muppets.

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## ringtail

Bwahahahaha.

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