If your sills was good, I'd say "Fix er up!"

Mr. Blandings meets with Joe Appolonio. I met with John Apolis, owner of CSES structural engineering. I paid for an hour of his time, and I was hoping he would load me down with free information. Not so much, but he didn't leave me empty-handed in that department, either.

We don't have to modify the existing house unless we're applying new loads to it. That makes sense. He was surprised that I would consider trusses over the Trees Room, because they're so tall.

Getting the glass right to the soffit look that I have in mind is a simple matter of cantilevered posts. Not cantilevered horizontally, but vertically. The post leaves the shear wall and sticks up into the sky, supported by the part that's embedded in the wall below.

Mr. Apolis' multi-cantilever design

He sketched a roof framing system that works for me: Some number of cantilevered posts. Run beams on two sides (E and W) and let them cantilever past the last posts. Hang another beam on the ends of the cantilevered beams. We have such a "hung" beam at the N and S ends. Those beams hang past the E and W beams--cantilevering in a different direction--and they support outlying beams that are parallel to the first set of beams. The members get lighter as we move out. The last two sets of beams hold up the soffit and fascia. Between the first set of beams, we use joist hangers for 2 x 12s (could be 2 x 10s per IRC table R502.3.1).

Problem with the Trees Room is that we need a "third wall" for lateral stability. We agreed that the BA 3 north wall would do, and that it would be good if it aligned with the closet in BR 3, so that the shear wall would be longer. He prepared me that we probably need to trench in the slab for a new footing for that wall. For uplift, it might even be good to just run it all the way to the west wall.

He suggested heavier posts at the SW and SE of the Trees Room at one point, maybe 4 x 8, but then thought that glu-lams, like 3-1/8 x 9, would be stronger and more attractive. I like that he's thinking "beam" thoughts about posts.

Simpson Strong-Wall

As for the garage door, we need Simpson Strong-Wall, because the little stems are too narrow for standard shear ratios. But he said that I might only need one. But then he explained that I'll need a beam across the garage parallel to the garage door header. The garage door header is necessary because the hip roof loads that wall. The second beam is necessary as a drag strut to transfer wind load on the west wall to a shear wall at the entry closet.

He also sketched what seems like a horrible over-design for the kitchen and explained it to my satisfaction. He says span the 10' width with two flush headers--one in line with the existing north wall, the second parallel, but under the hip ridge. From those headers, come up with 4 x 4 posts and support the ridge with another beam. That beam cantilevers back over the existing roof and--voila--the kitchen hip roof doesn't add a feather's weight to the existing roof.

He seemed to think a beam at the extended garage hip roof was necessary, also, but that could bear on a post on the second garage beam.

We discussed other ways to brace the Trees Room, and he liked cross beams and threaded rod cross-bracing, one or both. He mentioned steel and I told him it was too expensive--I think he was feeling me out. What I call TSC (tubular steel column), he called HSS (hollow structural sections, I know now). HSS4x4x1/4 is 12.21 #/ft, so a 13' column would be 158 pounds. MetalsDepot cost is about $16.32/ft (not including shipping or fabrication).

I got along with Mr. Apolis well enough, but I was underwhelmed with the information he shared. An hour of his time is not enough for him to consult a book or a built project on my behalf. We just chatted generally. He evaded when I tried to pin him down, such as on the live/dead load required for a roof garden. I'll send him the plans so he can bid the structural design, but I'll keep looking, too. He mentioned that he plays guitar and is a member of the Songwriters of Seattle.

Apolis warmed to the challenge of the Trees Room toward the end of the meeting, but I guess I would have liked to hear him sell me on paying him hourly to brainstorm and run tentative calcs for various alternatives. Instead, he sees it as a standard gig--so much for the calcs and marking up the drawings.