How big a tree do i need?

[tommer9]

I have had an enquiry into some 12metre long, 12" square douglas fir beams, to be used for the walls of a cabin, swedish style. The job will involve me felling the sticks, someone else extracting them and delivering them 100yds up the road to my customer where my mill will be set up. My customer has arranged the purchase of the sticks, provided the estate has them big enough.

 

The only bit of the whole project about which I am unsure is this: in order for me to get 12" square of heartwood, using Douglas fir, how big a stick would i need in order that at 45' high i can get 17" of heartwood? I am assuming that with 17" of heartwood the stick would be about 20-22" diameter........so what DBH is that if the stick is 22" at 45' high? Is there a formula for this, or published tables? I dont have the blue book, maybe it says in there?

[harvey b davison]

Sorry havent got a clue, but it does sound an interesting project. Keep us posted please.

[Big J]

Not sure either, but that is going to be a monster stick. The weight of the beam alone will be approaching 900kg.

[combined tree services]

working it out roughly the tre would heed to be roughly 86ft tall .

 

min you my rough calculations could be wrong !!!

[tommer9]

I think you may be a bit out there Dave....the Larch i was felling back in the summer was 70' tall, and wasnt even 22" DBH!I was reckoning closer to 100' TBH.

[arbmark]

blimey tommer if it has to all be heartwood and squared up then you are talking massive surely, but you seem to have the trees already in mind, so its probably the big ones! short of climbing up, topping them off and having a look i dunno mr!

[combined tree services]

I think you may be a bit out there Dave....the Larch i was felling back in the summer was 70' tall, and wasnt even 22" DBH!I was reckoning closer to 100' TBH.

 

hmmmmm like i said it was roughly speaking also my working were baised on some large open grown spruce that i worked on a few months ago up by the halfway house in the glyn valley

[tommer9]

blimey tommer if it has to all be heartwood and squared up then you are talking massive surely, but you seem to have the trees already in mind, so its probably the big ones! short of climbing up, topping them off and having a look i dunno mr!

 

I had that thought...couple of experimental trees......

 

hmmmmm like i said it was roughly speaking also my working were baised on some large open grown spruce that i worked on a few months ago up by the halfway house in the glyn valley

 

Some big trees up there Dave.

[delabodge]

I had that thought...couple of experimental trees......

 

 

 

Some big trees up there Dave.

 

how you going to mill something that long?

[Graham]

That's one hell of a length. Surely it's not going to be an unsupported span? If it is supported then can't they splice/joint two shorter lengths?