The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: dbarron on October 19, 2017, 04:23:08 PM

Title: Timber frame bent/ truss design
Post by: dbarron on October 19, 2017, 04:23:08 PM

I am planning on building a timber frame 16 X 28 porch. It is I'll be attached to an existing stick frame house, off the gable end.  After the frame is completed, I plan on covering the house and the new porch frame with a common metal roof.  The bents will span the 28ft direction. The existing structure has a food pitch of 4.8 , I want to match this pitch with the new frame. The trouble I am having is that if I do drawings to scale, the bents / trusses don't look right. All the designers seem to be too crowded, or just not aesthetically appealing to me. Anyone have any advice for designing bents with low pitched roofs? Pictures would be great. Thanks!
Title: Re: Timber frame bent/ truss design
Post by: dbarron on October 19, 2017, 04:26:37 PM
I work third shift, so I am going to catch a few zzzzz, so I may not answer back right away, but I will check back later in the evening. Thanks!
Title: Re: Timber frame bent/ truss design
Post by: fishfighter on October 19, 2017, 05:29:03 PM
Your post would get responses in the Timber framing threads. ;D
Title: Re: Timber frame bent/ truss design
Post by: rl on October 19, 2017, 05:38:48 PM
what are bents....been a builder all my life but never heard that term
Title: Re: Timber frame bent/ truss design
Post by: dbarron on October 19, 2017, 06:54:59 PM
Oops, sorry I will repost my question on the timber framing board.
Title: Re: Timber frame bent/ truss design
Post by: Brian_Weekley on October 19, 2017, 07:02:33 PM
Quote from: rl on October 19, 2017, 05:38:48 PM
what are bents....been a builder all my life but never heard that term

Traditional timber frames are typically built as frame cross sections called "bents" and independently raised.  This is an example of raising a bent:

https://www.youtube.com/watch?v=WG0MYCKcN-g
Title: Re: Timber frame bent/ truss design
Post by: Don P on October 19, 2017, 09:31:36 PM
Try lowering the tie and then to lower the spreading thrust bring the posts way in to give a very generous "overhang", moving towards balancing much of the rafters load over the posts

Edit: this is along the lines of what I've been thinking;
(https://forestryforum.com/gallery/albums/userpics/10017/4_8bent.jpg?easyrotate_cache=1508500706)
Title: Re: Timber frame bent/ truss design
Post by: dbarron on October 21, 2017, 09:23:12 PM
Good Idea, I may play around with similar designs. Thanks for the advice!