Hello, I am a new member here. I have property with lots of big trees, white pine and white oak, and plenty of free time. I would like to put up a timber frame house on it, and I have been reading a lot of Christopher Alexander, a rebel archetect and professor from the seventies. He strongly endorses lightweight concrete vaults, I like the idea because I could avoid putting in rafters and purlins one at a time while standing on a ladder... I'm not too comfortable with heights.

It would also allow me to have lower walls on the timber frame portion of the house, since the ceiling would rise quickly and give lots of head room.

So, without typing too much, do y'all think a concrete vault could tie together the bents as well as rafters and girts, once it has cured? Or would the leverage of the walls split the roof as they flex? Could I use a more short-lived alternative to girts (see wood-and-wire beams at bottom) to tie the bents together while the vault cures?

The way I would put up the vault would be to put anchor bolts into the top plate 3" apart and arch lengths of PVC pipe over them. Then I would stretch burlap over that and wire mesh over that. Then I trowel the thing over with 2" of cement with a lightweight aggregate. I guess vermiculite, maybe cellulose or something else. Please, if this is a stupid idea or wouldn't save me any trouble, let me know. I can take brutal criticism

Wood and wire beams: I read about this in barefoot archetect. It is a board beam with a post attached to the center of it, that points down toward the ground. Instead of reaching the ground it applies tension to a wire that runs the length of the beam. The length of the post depends on the load that the beam will be carrying.

Hello,

That's great. I'd go with just about anything Alexander suggests. Done a little dabbling myself - mini vaulting, nothing parabolic - and nothing as substantial as a complete structure from the ground up but with time and resources I'd love to have a go from scratch. Careful though your bound to get a lot of discouragement from experts in the field. The path you choose takes a great leap of faith at many junctures. In terms of practicality Alexander is none to keen on timber frames. Hope to read more from you here on the subject. That's all for now from here.

Greetings,

Don Wagstaff

I don't know enough about cast in place concrete to comment on that portion of your question. But, If you don't like ladders depending on your location and design, there are a variety of scaffold or powered lift options.

My only concern would be the service life of these options, especially the concrete. Modern concretes don't have a tremendous lifespan, especially when exposed to the yearly cycles of freezing and thawing.

Also anyone you could label as a 'Rebel' in any field scares me. There are good reasons for the traditions we adhere to, and good reasons for the systems that they are 'rebelling' against.

You can always assemble trusses on the ground, and lift them in place with a crane or some sort of rigging. Just find a buddy that's willing to ride on top. I've flown a lot of preassembled trusses in my day, it's pretty simple and easy.

Now, to back up a bit, I don't know anything about this fellow you mention, he could have great stuff for all I know. I just am wary of anyone who likes to totally discard whatever came before or is already in place. Then again, I come from the most tradition-minded race of people on earth

And hey, Les, how's it goin way up there?

Well David, its been a long cold winter. The capital city here broke its recorded snowfall record. Last week we had a storm that the old timers had to go back to 1948 to compare to. The shovelling out in some areas still continues. But the good news is it is warming up, the days are longer. It is spring right?