anyone build their own trusses before?

Hi all I'm recently rebuild my own dining dining area from an enclosed patio into a a proper double brick dining with huge open ceiling that showing off big jarrah trusses. My trusses are about 5000x1500. The thing is id contacted so many draft person and they keep asking me to change it to normal roofing and I said no. Also engineer will not draw my trusses as its a bit "exotic" for them. But I've seen people doing it. Anyone have any experience in this? Get the plan done and engineer and council approve? Here are some photos that id design

Have you thought about constructing a pitched roof, i.e. Ridge beam and then rafters. You can then line ceiling and butt your trusses up to it. The 'trusses' would then be cosmetic, you could make them anyway you like because they wouldn't be holding the roof up. The other reason for doing this is you will be able to stuff the cavity formed between rafters with insulation.

Pretty much as jrock_au has suggested. Otherwise, keep looking for an engineer that is interested. Keep in mind that your design is pretty ambitious...but achievable all the same. You've got some serious load distribution issues to tackle in order to pull it off.

Craig.

Are you an owner builder ? Lots of draftees and engineer's dont like dealing with OB's so it may be that, not so much the trusses themselves.What about cladding normal pine trusses (king post) in Jarrah ? That would allow you to get structure up quickly and treat cladding the trusses as part of the internal works ?Sam

Contact a some well known frame and truss manufacturers.

They can design it, engineer it and certify it.

Will take a bit of negotiating and you may have to contact a couple untill you find one willing to do it

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Originally Posted by jrock_au

Have you thought about constructing a pitched roof, i.e. Ridge beam and then rafters. You can then line ceiling and butt your trusses up to it. The 'trusses' would then be cosmetic, you could make them anyway you like because they wouldn't be holding the roof up. The other reason for doing this is you will be able to stuff the cavity formed between rafters with insulation.

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Hi there, thanks for your reply, yup these trusses is mainly for show no loads on it. I was leaving it for the engineer to draw me a proper roof frame on it. But then they don't like it! Zzz...

Quote:

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Originally Posted by Sam

Are you an owner builder ? Lots of draftees and engineer's dont like dealing with OB's so it may be that, not so much the trusses themselves.What about cladding normal pine trusses (king post) in Jarrah ? That would allow you to get structure up quickly and treat cladding the trusses as part of the internal works ?Sam

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Yes i am OB, maybe thats why :(... It will be some exotic rosewood ceiling lining installed that's why the trusses is to match with the exotic vintage look for it. I don't really care how's the roof frame work as long as it strong and engineer approved it because no one would see them anyway, I was doing tones of research on these trusses and if you want to use them as load bearing trusses you would need the timber to be certified as well. That's why I use them as purely to look only. Also reason why I posted it here because the way I design my trusses is with traditional joint only. So far I'd found these guy called roger from transform drafting would draw it for me. Seems like he drew some before by the way he talk to me

Different from yours. These trusses are 8m, 4m to the centre post. They support a 3m x 8m skillion roof and an 8m pitched clearstory roof. I cut the truss on the ground and assembled them bit by bit on a 3m high trolly 1.2m x 2.4m. The posts and braces are 100mm x 100mm spotted gum ( the posts go past the windows to a top plate ). The chords, 2 pcs of 100mm x 50mm top and bottom. I also was an OB and had the whole structure engineered without any drama.

http://i686.photobucket.com/albums/v...psd471c7d5.jpg
http://i686.photobucket.com/albums/v...ps6d014a41.jpg
http://i686.photobucket.com/albums/v...psf8bf0eb6.jpg

A few more pics to give the trusses some context. The trusses on the outside walls are panelled. The central room is 5.5m to the ridge. No
architect, just engineers. I mixed a few Bris. suburban train stations and atriums of the hotels and malls I was shopfitting in the late 80s. The
central trussed room (8m x 4m ) is surrounded by a 3m hip skillion roof, mostly verandah. In Qld tradition, I made more rooms of the verandah to
the east and south. The north verandah , 3m x 15m now has a 4.5 x 4.5 end. Very liveable.

http://i686.photobucket.com/albums/v...pse0636b40.jpg
http://i686.photobucket.com/albums/v...psa7013364.jpg

Hi,
I think this is a great project and something worth continuing with. Just over 2 years ago, I replaced the roof over our main room with exposed trusses.
My area is 11 meters by 6.6m plus the garage which would make it a total of 17m x 6.6. I have a total of 5 trusses. They have a 33 degree pitch and are made from recycled f7 douglas fir. The tie beam is 200x90mm with the rest being 140x90mm. They do the job fine and so far are still standing. The trusses are spaced 2.6m centers through the main room. This is only to make them even. I have a spacing of 3.2m in the garage. My design has hips at each end. I have a tin roof.
Your design looks fantastic. If you build the trusses from jarrah, they will be more than strong enough (and very heavy). The center beam will have to be quite large which is the only detracting thing. The rafters will not have to be overly large as they only span some 2.8m (approx).
I would consider building it differently. By adding another truss, this could give you centers of approx 3.3 meters. This would enable you to then use purlins of approx 140x90mm at 1200mm spacings, and followed by 90x45 rafters at 900mm centers, then 90x45 battens for the roofing material. This is the method I used. It uses more material, and takes more time, but it worked out well. The underside of the purlins gives you something to fix the ceiling to, either timber, or batten out for plaster. Remember if you are battening the underside to raise the purlin to compensate for this. You do not want to loose the visual portions of the truss members.
When selecting the timber, I looked into timber grading and considered doing the course. I was advised here in Melbourne that it did not have to be graded by a registered, or licensed timber grader. Someone suitable qualified is sufficient. I downloaded the Australian Standard with the help of a forum member, graded my timber. It's not very hard.
If you are interested, I can located the engineer I used. He was great. Nothing was a problem. I have used concealed steel plates in the design. I will try and post some photo's tomorrow.

BallPeen

I liked your approach. there was a time when I was right into that sort of thing. In some ways I still am in that I am planning a ridge truss to support roof beam on an extension, but the truss will be in steel and not visible.

My understanding in the construction of any timber truss is that the engineering considerations revolve more around the connectors than the timber components. Typically we see plate connectors on the modern cottage build with very flimsy timber parts. These are unsightly and for visible trusses we use bolts possibly with ring connectors or others purpose built devices.

Jovian

Keep hunting for an engineer who is prepared to step outside the square. There are around but most want to remain within their comfort zone.

Regards
Paul