Wood Truss - Improving strength of Nailed Member Joints

[MarshfieldTimC]

I recently purchased a 30' x 40' (unfinished) pole shed, and I would like to add a ceiling and insulate it (along with the perimeter walls). The shed was built (in approx. 1990) with 6x6 posts spaced 8' apart, with wood trusses (spanning the 30' width) attached to the posts. The trusses are apparently home-made (built from scratch by a carpenter) and were not 'engineered'. All wood members are attached to each other using nails. I want to improve/strengthen the wood member joints, as I was told that the nailed joints are a likely weakness. Does anyone have experience with something like this? {For example, 2x6 cross member attached to a 2x6 bottom chord with 5 nails - Can I improve the joint strength by bolting these joints together (drilling holes, using flat steel plates, etc.)?}
All comments appreciated.

 

[HouseBoy]

Best to review materials on pole buildings.
Google: "NFBA" (National Frame Builders Association)

FWIW - I think most would discourage the use of shielding by trees as justification of a load (although it could explain the behavior to date).

 

[KootK]

Cables would definitely help but, to divert load away from the problem heel connections, the cables would need to directly connect the ends of the top chords rather than just the tops of the posts. There would also be issues of strain compatibility between the bottom chords and the cabling that would warrant the attention of a pro.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.