Because we have a basketball goal at one end of the barn we needed to leave enough head room for them to play ball and, we didn't think we needed to brace every rafter 1/2 way down with a 16 foot 2 x 6. So, what we finally settled on was to cross brace four of the new rafters that were in the center of the building with 16 foot 2 x 6's that are 5 feet down from the peek. Then all of the remaining rafters got braced with an 8 foot 2 x 6 that is about 2 1/2 feet down from the peak.

When we attached the new braces to the existing rafters, we used 1/2 plywood gussets, like you would when building a trussed rafter, to attach them. We used construction glue and sheeting staples (7/16 crown by 1 1/2 long) to attach the plywood.

Because the 2 x 10's are 4 inches wider than the existing 2 x 6's we attached the braces to the new rafters by lapping them on the edge of the 2 x 10 and gluing and screwing them in place.

For each of the rafters with the 16 foot cross ties we also ran a 2 x 6 vertically in the center that comes up under the ridge board. These we joined it with 1/2 inch plywood gussets, glue and staples.