Attic Truss with Raised Heel
Attic Truss with Raised Heel
(OP)
I've been looking at a number of garage designs recently that employ an attic or storage truss. I'm finding that a lot of them tend to use raised heels to allow for more head room while having a lower roof pitch (ie. 6/12 - 8/12). I've been thinking about adding in raised heels for the attic truss type in the plugin I've been working on.
A quick mock up would look something like this:

View model here:
https://3dwarehouse.sketchup.com/model.html?id=u20...
Ignore the unbalance in the panel lengths, in practice and in the plugin they will be properly balanced.
What I do have a question on is the use of a top chord splice as shown in the above image so that the overhangs do not have to be as deep as the top chord in the non-triangulated region of the truss. I have never seen a splice used on a attic truss with a raised heel, I don't see why it can't be done but it is always nice to have a confirmation that someone else is doing this sort of thing in practice.
A quick mock up would look something like this:

View model here:
https://3dwarehouse.sketchup.com/model.html?id=u20...
Ignore the unbalance in the panel lengths, in practice and in the plugin they will be properly balanced.
What I do have a question on is the use of a top chord splice as shown in the above image so that the overhangs do not have to be as deep as the top chord in the non-triangulated region of the truss. I have never seen a splice used on a attic truss with a raised heel, I don't see why it can't be done but it is always nice to have a confirmation that someone else is doing this sort of thing in practice.
A confused student is a good student.
Nathaniel P. Wilkerson, PE
www.medeek.com





RE: Attic Truss with Raised Heel
I do have a suggestion. The small kingpost right under the peak does absolutely nothing. If the collar tie is less than 10' long (which is rarely the case) it's totally unnecessary.
RE: Attic Truss with Raised Heel
Common spans for garage attic trusses (where I usually see them in use) would be 24 or 26 feet with 12 feet of attic width. Your example sketch looks like it might be a bit longer than that so I really expect the top chord demand to be significant.
I don't see a big problem with the top chord splice but for that purpose, maybe simply scabbing a tail onto the side of the truss would be adequate.
RE: Attic Truss with Raised Heel
______________
MAP