Northern White Cedar

[Jeff]

Is Northern White Cedar suitable for Timber frame construction?  My concern I guess whould be strength. Appearance and stability should be a given plus I would think, but would it be strong enough without having to use massive sizes? I am talking about a 70 lb snow load area.

[SwampDonkey]

I guess I can't answer that directly, no experience with timber framing. But, I have seen a new camp built totally from northern white and they used larger dimensions than if it were spruce. The door on the place looked like it was built to keep some nasty beast out. Oh wait, I meant the vandals out.  Why not use spruce on the roofing, then have some cedar shingles on there. Last you out young feller. ;)

[Jeff]

I don't have a lot of spruce, but I have an abundance of pole size and bigger cedar.

[thecfarm]

Don't know about northern cedar,but the cedar I have around here my father always said was not good for holding nails.We used some cedar poles to hold up the old garage with it.It was built in a wet hole and it was trying to fall over.He said the cedar would hold it up fine,but would not take a quick jolt.We used some for bed pieces to hold up the logs with cedar on the yard to level the pile out.When the trucker would come he would drop a log on them and snap them in two.With the logs on the cedar it was fine,but the sudden weight would snap them off.I guess a steady strain is fine,like a building,just hope a tree will never fall on it.  :D There used to be many pole barns built around here with cedar. They would use something else for the rafters,trusses.

[SwampDonkey]

It's the same cedar, but I don't know about the nails not holding. They hold cedar shingles, potato barrels (holding 165 lbs) and lawn furniture and maybe the odd  ??? hot tub  ??? It hasn't fallen off the walls inside the house yet in 30 years. ;D Pretty rugged on canvas back and birch bark canoes people have built for ......well.......a very long time. ;)

[thecfarm]

I was talking more about nails going into cedar not through it.Most roofs and walls are not cedar.Don't know about potatoe barrels and the others.Just repeating what a old timer had to say.They were right a lot of times.   ;D

[Gary_C]

From Softwoods of North America, FPL-GTR-102:

Northern White-Cedar    Thuja occidentalis

It is soft and has low Mechanical properties (bending and compressive strength, hardness, stiffness, shock and splitting resistance, and nail and screw holding abilities).

Other than that, it has about 75% of the strength of White Pine and 50% of Red Pine. 

[limbrat]

With northern white cedar at 850 shear 1bf/in2  i get a roof load bending rafter, simple span of 472 psf. for 5x10"x10' rafters on 12" centers and 188 psf. on 30" centers.
On double span 5x10"x20' with a brace at 10' center i get 335 psf.on 30" centers.

That is before roof weight and snow load. Nwc has low shear factor like Gary said about half of red pine.