The Big Addition: Steel

(... at last ...)


Steel is real

That's an old bicycle saying. But it's also true if you want to put in big windows in earthquake country. Our design has a steel "moment frame" at the south end of the great room which will house windows and an exterior door, and will also help keep the garage post-less. After a hot week, the fog moved back in big time 9/12 - it did not clear until early afternoon. But after several delays, Dietrich Iron Works showed up with King Crane at exactly 0700. We took many pictures. A healthy subset here.

Once in the driveway, King Crane deployed outriggers to steady the crane, and by 7:30, steel was being unloaded onto the driveway and the slab. Around 8:30, the first vertical girder was lifted into place and by 9:20, the two ends and lower cross beam (the goalpost) was in place. The center upright was next, followed by the middle cross beams. By 10, Dietrich had 6 of 8 girders in place.

Dietrich had ordered a boom lift (ie, aerial platform) to work on welding. Problem was it came on a semi - very tough to get a semi to our driveway. Andy was free. How fast does it go? 5 mph? No problem. Andy offered to drive it down from the fire station. Got to try new things. A few pictures here of him arriving - in one piece.

By 10:15 the moment frame was in place and bolted together. The remaining girder (that carries the transition from the main house to the great room) needs 6 "knives" welded onto it; the knives slot into the roof rafters and are bolted through (you'll see this later). One side of the roof is a 6 in 12 pitch; the other, 3 in 12. The knives were all made 4 in 12. Oops! So Dietrich just set up a jig at the back of the truck and recut them to the correct angles with a torch. Then, they were welded. The plan was to hoist that girder as well, but since the crane needs to come back to do the rafters anyway... a wise choice not to rush things.

While Dietrich's crew took a lunch break, the sun finally came out (around 1:30). The moment frame is bolted together, and King crane has left the building. A few shots here of the frame in place. Now, every joint needs to be welded...

Wednesday, 9/12. This is King Crane's... Dietrich follows the crane in with 9... With the outriggers deployed, unloading... The first pair of small beams is... Setting down.... The art shot - we'd call this... Installation guide?... The verticals are the first to be... Up up and away... Nearing the target... Lining it up on the bolts.... In place, bolt it in. Just like an... The east vertical is lowered into place.... We've got endposts! By 9:00, the fog is... The lower horizontal beam is lifted...... Climb aboard. One iron worker prepares... This is probably a lot more terrifying... There's a bit of jumping on this one to... Once the goalpost is set, the center... The center divider gets bolted.... Four down, four to go.... Middle cross beams. Looks straight from... Not quite sure how he's holding on? It's... These specially shaped wrenches poke in... Second middle beam.... Positioning the bolts. Not quite 10:00.... Andy tries a new toy. Driving the Genie... Pretty intense trip, though. (No animals... Back to business, the first top cross... And it is bolted in.... Chaos! Ladders, posts, scaffolding,... Crane operator at work.... Last piece of the frame.... Steering input...... Held in place by the crane, the last... Bolting the other end... Dietrich's crew recuts the... Weldmaster Clay starts to weld the... It's like looking at a magnesium sun.... Finishing touches.... One knife in place. Five to go.... The crane is used one last time to flip... Erected in just over 3 hours, our moment... Looking at the frame towards the west.... Iron workers like to sign their work.   ...


Moment frames are often just bolted together. For a specific earthquake resistance, the joints need to be welded, and our structural engineer called for welds. Work continued after lunch with welds until they ran out of time. Note that all of this work is being inspected while it's going on (county requirement). The following day, Dietrich's crew returned to finish the welds. The fog from Wednesday was nowhere close. A good opportunity for some clear pictures.
Clay sets up  the platform for welding.... Middle joint. Originally, there was a... Good to have a spotter.... Like watching fireworks... Follow the... This camera setting isn't fast enough to... Post-weld closeup of a connection point.... Raised and welding complete on a quiet,... A look up... Morning is a good time to see the bolt... It seems like a huge structure, but...

Second Lift

The week of 9/17 - we've been at it for 3 months. Seems like a fine time to pull in a favorite comic, in the first thumbnail to the right. The weather started to play a role. Some of the crew started the week under the weather, and the weather forecast included possible showers. This made for an even busier week than planned. Some time was dedicated to temporarily closing in anything that was open to the weather. We had recommended that the GC hire Conditioned Air to do the ductwork in the addition, and they showed up 3 days early. Most of the electronics for a new 3-zone system are in place.

Much of the work was preparing for the second lift - the transition beam and the 3 exposed 6x14 roof rafters for the great room. Recall that the 6 "knives" in the beam slot into the 3 existing and 3 new rafters. Creating those slots is a multi-step process involving drilling, pre-cutting the edge of the slots, then using a chainsaw to carve out the core.

Getting the crane here was a scheduling challenge, first Wednesday, then Thursday. Considering that it was very windy on Wednesday, it worked out for the best. While awaiting the crane, garage framing got going. You can see temporary plywood and plastic on the walls and roof of the main house in some pictures. West Coast Cranes showed up around 4PM for the late-afternoon lift. The crane is used to flip, lift and set the transition beam, then lift and set the three 24 foot 6x14 douglas fir roof rafters for the great room. It took just about an hour to set the transition beam - getting all of the attachment points to line up was tricky. It was quite close from the prep work, but some trimming and pounding was necessary. The rafters only took about 25 minutes!

Once the crane left, the rafters were bolted to the knives. A very tricky process - imagine drilling a 5/8 inch hole straight through a 6-by and hit a target half way through. About an hour and a bit later, the bolts are in place.

Friday was a strange weather day - alternating bright sun with scary clouds. The goal was to finish framing the ceiling of the 1-bay garage and wrap up the house for weather as the forecast was for rain Saturday. Just to get an idea for the 2-bay floor level, a lightweight truss joist was temporarily set - this will be replaced next week with a 16 inch paralam which probably weighs about 300 pounds. As all of the structural steel is installed now, we'll close out this phase!

A favorite comic says it all.   ... After four layers of rigid foam, the... Conditioned Air works fast. In a day,... The transition beam. Anything welded has... The existing rafters slotted for the... Valente drills out the end of the slot... Antonio cuts the edges of the channel.... Jimmy takes out the core with the... Finished product.... Temporary weather proofing on the roof... Framing the one-bay garage begins again.... The back wall is framed.... Starting to look like a garage! The roof... Center paralam beam is dropped in.... Truss-joists finish off the back half.... Then, the crane showed up around 4PM.... The boom is up and ready for lifting 9... First order of business is to flip the... Maneuvering the beam into place.... Slowly descending to the crew...... There are 5 attach points - the post on... Caught the post on one side. Ignore the... Here you can see the three knives just... Slotting in...... Almost there...... Nicely centered on this post. A few... After some pounding with a sledge, the... Looks like we might be in for some... First rafter. If you zoom in, you can... Dale guides the rafer into the bracket... One down, two to go.... The second rafter flies in.... The slot for the transition beam is on... Two rafters in.... The third rafter went up backwards so it... Slotting in...... Lining up with the moment frame...... The crane supports the last rafter while... A view from below... By 5:30, the crane was on it's way home.... Sun behind the moment frame.... To drill out and bolt the rafters to the... Each rafter (new and old) gets four... The front paralam is installed in the... After the temporary walls and plastic... Valente and Antonio install more... Done! The ceiling of the 1-bay is also... Atop the moment frame, installing the... Even up here, there's a sill plate. Up... Finishing off the weather proofing.... Setting a temporary floor joist just for... Haven't taken a shot of this view for a...