The Forestry Forum
General Forestry => Timber Framing/Log construction => Topic started by: Don P on November 17, 2007, 07:11:44 PM
Not TF or log but a good truss to consider for an affordable home.
We set some of these Monday on an ICF foundation. This is an attic truss, it will get a piggyback "hat" to finish the peak. The truss gives us floor and roof framing in one set and provides clearspan space below. We've used these twice in the past couple of years, I think we got it right this time. Notice the top chord launches from the overhang not from the wall line. Sort of like the old raising plate ;). I've drawn the wall bearings in red, the left side has a 4' overhang the back got a 2', that could vary of course. The floor is 16' wide on a 29' truss with 6' of headroom at the wall and 8' headroom within 2' of the wall. We've stacked 3 together as a girder, left a 10' gap across the center of the building and stacked 3 more on the far side of that opening. A cross dormer 10' wide will go through that area. Our stairs will come through that area. I can envision putting these on a single story of superior walls or ICFs and having a very reasonable house.
(https://forestryforum.com/gallery/albums/userpics/10017/attictruss.JPG)
That is a good use of material. Trusses can be so efficient when done correctly. Are they glued gusset trusses and where do you get the design from? Joe
No these are metal plate connected 2x trusses from the local truss plant, they do all the engineering. For the girder trusses I let them know how I would build the dormers so they could check and give me enough plies of truss to bear the loads.
The garage on the left of this pic has the same type of truss, we built an apartment upstairs. The top chords launched typically here, from the wall line. We picked up more useable feet of room on the current one by running the bottom chord out and launching them from the fascia line. This one has shed dormers, the current one will have gable dormers.
(https://forestryforum.com/gallery/albums/userpics/10017/bent1.jpg)
What deminsions are the in members? 2x6 over 2x10?
The one at the TF has 2x8 top chords over 2x10 bottom chords on a 26 foot wall to wall span. The one at the ICF house has 2x6 over 2x10 on ~23' wall to wall span. I noticed the stamp on the 2x10 bottoms is machine rated SYP at Fb 2400 psi, 2.0 E ... that is some dense tight wood.
Don, that's a neat design - thanks for sharing.
Scott