Thread: Boxed Heart Posts

I have also heard that 175x175 is the min for structural timber with boxed hart . A grading requirment I think but have not done the course so not sure

Not heardof that requirement, Sigidi. I've done quite a few at 6" and no complaints to date

Yeah I pushed out a 6" BHP and the client was happy enough, but another fella on site who flicks switches on the ASM was the one who said about the 7" bhp. I don't reckon there is anything regulation-wise about it, just knowledge/experience of the timber and it's characteristics, to know which bits you can and can't do it with.

Obviously a bigger section bhp will ahve less tendency to have the heart cause splitting on the post faces - so a 4" bhp would be 3 or 4 bits of firewood after drying a bit, so that would be a no no, but 6"bhp's are a fair hunk of timber to split??? Dunno gotta find out more...

spoke to timber qld they say AS2082 ,175x175 min for boxed hart .

Now, some questions. Most important, how big is the heartwood in relation to the remainder of the post? If the heartwood is 100mm in diameter and the post is 175mm square there isn't really all that much true wood in the post is there?
What are you going to do with the post? If it is structural, forget boxed heart. Do yourself and your customer a big favour and use a post sawn from the good part of the log. Old-time sawmillers would use the section near the heart for fence palings, tomato stakes and oyster sticks, then burn the heart because it was rubbish. Having been involved in pole-frame building for a few years now and having seen what can happen to boxed-heart posts (300mm x 300mm White Mahogany / Tallowwoods that opened up like a dunny door) I would really consider something else.
For a chook pen, yeah, they'll do. For a house where they might have to be replaced because they cracked open and the owner wants them replaced, Not worth the dramas.
Call me old fasioned because I am.

happy to use hart free timber , Just show me the tree that you can cut a 300x300 out of .I have pulled down a few buildings in the cbd with 300x300,300x200 etc you are right some do crack or twist maybe 10% , but all cut boxed hart .

Few and far between now, unfortunately. This job used 36 such posts, each 3.3M long. Architect designed and built, all timber and rammed earth infill walls, sod roof, very interesting design. How many Koalas starved because of the timber that went into this place, no-one will ever know. Then there were the 300x75 toof beams and the 300x50 top plates for the walls.........
Architects!
Dennis.

sigidi the actual specification is that the heart wood take up no more than a ninth of the post, so if you draw a noughts and crosses game over the post, and if the heart doesn't extend out of the centre square you can grade the post . i know this sounds simple but thats the AS 2082-2000 standard if you want i can look it up and quote it word for word out of the manual but thats pretty much it .it just depends on how large the heart wood is

A very timely thread. A work colleague asked today if I could knock out some 200 square posts for the entrance of his new home. I don't really want to but he works in an area where it can be usefull to have someone who owes a favour. The posts, I'm told, wont be structural but I'm not sure having one split wide open is going to look good on a new home so I had already decided on solid timber. Of course he wants them in red and preferably blue gum but our place isn,t exactly over endowed with this species and the big one I can get from elsewhere has been delayed by an overpaid envoiromental "expert" who doesn't mind wasting your tax money to save a couple of trees of no significance what so ever. The only red timber I have available is Turps and it's more orange really but it's that or wait.
Wondering what opinions might be out there on the suitabilty or not of Turps for 200 square decorative posts.

Alrighty then....

well after a bit of deliberation and research, everything from above is truthful.

As 2082-2000 Heart is allowed in hardwood with a minimal dimension of 175mm either face or edge. Providing the heart is in the central 33% of the piece (ie the noughts and crosses thingo)

also...

Heart is defined as Juvenile wood fibres of low strength and subject to excessive distortion when drying, lower density material containing growth rings with a radius of less then 50mm.

and further

Heart and pith material have no effect on the strength of cypress and no special provisions for grading exist.

Now knowing the above info regarding the definition for heart saying the heart is 100mm dia and knowing it needs to be no bigger than the middle square in noughts and crosses, this then implies a bhp cannot be smaller than 300mm and still be structural??? Can anyone else see where I'm coming from with that?

Originally Posted by THE BARON

Wondering what opinions might be out there on the suitability or not of Turps for 200 square decorative posts.

Baron I was given a turpentine tree and found it was very durable, so decided to rip it into 4x3 posts to use on our farm ( could use another 300 more if someone has the logs for me to get them out of? the boss has 'plans' )

Anyway the long and short of it, they cut well and looked really good, but a little time down the track they went from 4x3's to something akin to starfish!! Yeah not very pretty, if I don't have to I wouldn't use turps for anything again, unless I could get it kiln dried, I haven't come across anything which collapsed, distorted, tore apart and generally became unruly as much as turps. I had the stack strapped with 3 ratchet tie downs over 2.4m and kept re-tensioning them every couple of weeks until the wouldn't give me anymore.

Something like an 8" post I'd recommend against Turps - but just my personal experience.

I've had really nice results from ironbark poles 230mm+ boxing 5" posts, the whole 400sqm house is swinging off them, no nasty splitting on any of the 50 something posts. The same can't be said for blackbutt - they came out terrible and the boss wants 'em gone, the blackbutt isn't 2 years in situ??

Originally Posted by Sigidi

Now knowing the above info regarding the definition for heart saying the heart is 100mm dia and knowing it needs to be no bigger than the middle square in noughts and crosses, this then implies a bhp cannot be smaller than 300mm and still be structural??? Can anyone else see where I'm coming from with that?

From the facts you have given, I would read it the same as you, 300x300 to allow a central 100x100 heart section. Kind of discounts the 175x175 if it is correct.

Thanks Sigidi, you've confirmed what I already believed. The stuff I've milled over the years has been quite variable when seasoned, very similar to brush box and I don't mill that anymore except for building chook pens. And your calculations arn't wrong. Lesson1. Don't read regulations, you'll go mad.

the hart meaning center 50mm of the hartwood must be in the middle square thing and the min size is 175mm correct me please if i have this wrong but a log hartwood is everything that is not bark or sapwood and the hart refers to the middle of the log