This post is all about erecting the steel arches and rebar for the radial roof vaults. This process took us a few weeks to get done and really looked great. I’ll put details and a lot of pictures down below, but first, the time lapse videos…
The Video(s)
Yes, I had to break this one into two videos.
Here is the first 6 vaults going in…
And here are the remaining 4 and a final walk thru.
The Gallery
A picture is worth a thousand words, so lets talk about things in the context of a gallery…
We passed the inspection without any trouble.
Another exterior view
After chisteling out the concrete for the hole, I also cut that piece of rebar and then cleaned it up nicely.
I had forgotten to leave a whole for an 8 inch duct to get thru this concrete wall. So I had to drill one out.
The kitchen vault before starting on the dining room.
This is the fresh stucco on the outside of my office window.
While I worked on Steel, Sherri worked on Stucco…
We welded each steel arch to rebar pegs (#5) drilled into the concrete ribs.
Pic of the first 3 vaults in
A sunset view from the bedroom roof
View from the bedrooms
This room as 3 vaults and covers 90 degrees of the circle (the fish eye lens flattens it out). Eventually, we will have our TV in here, etc.
This room was easy to work in because of the nice floor.
David in the playroom
I needed all the vaults to be the same height, so I used a laser to set the height of the scaffold when it was out in the uneven dirt. Then we set the steel arches a fixed distance above the scaffold deck using a car jack to make the final adjustments.
Here I am just trying out one of the steel arches to see how it “fits” and how it looks
In this shot you can see rebar arches lined up and ready to go while Sherri continues to work on stucco.
While I was focused on the steel arches, Sherri looked after stucco work.
Michael helping me work on one of the vaults.
The kids treated the place like a jungle gym
While working on the living room vaults, I looked down and noticed that the steel columns had filled with rain water. So I drilled holes to let it all out.
It sprayed for quite a while.
Close up on the bedroom dormer stucco
It was nice having a skid steer to move heavy things around.
In this case, we got a delivery of 2 tons of rebar and i could just move it to where I wanted it.
I bought a much smaller tractor to replace the skid steer and it couldn’t even lift one of these bundles.
Working under the vaults felt a little surreal at times
A closer view
IN this view, you can see my form material experiment
We knew that we would eventually need to attach formwork below the rebar, but I wasn’t sure how well my options would hold up to the environment…
I ended up using just the un-urethaned brown board, more on that in an upcoming video.
We celebrated the 4th from the roof with some friends…
We bought a Kubota to replace the skidsteer. It has only 1/3rd of the power, but it won’t tear up the ground.
Here Sherri is putting the rebar chairs up in the guest room ceiling.
The top of the guest vault. This one already has the lath, etc. and is ready to shoot.
Not sure why I don’t have any video footage of the guest room being done. Maybe it will turn up later or maybe it is lost forever.
Shot from the kitchen looking toward the dining room and living room
In the kitchen taking a pick of the dining room. The kitchen island will go under that concrete rib
In the dining room looking toward the living room
Standing in the living room looking toward the kitchen…
Backing up with the camera
Just another shot
The living room, dining room and kitchen are all open concept
After waiting more than 2 months for our shotcrete crew to come out, we managed to find a new gunite crew in the area. S.A.M. Pools came out and did a great job. We can talk more about the details in the blog, but first, the Video.
The Video
The Wait
Waiting for contractors is just a normal part of building. It just gets worse when you are an independent builder because the contractors all have more regular clients that are more important to their long-term success than your “filler” job.
We couldn’t get our shotcrete guys to come out and the summer was fading away, so we began the search for a replacement. Gunite and shotcrete crews don’t seem to put any effort into direct advertising. Most don’t even bother listing their phone number anywhere, never mind having a website. Instead, they work for landscaping and pool companies.
So I began to call those sorts of customer-facing companies. However, those companies do not want their subcontractors getting other work because it could lead to increased prices and reduced availability. I could see that they had done shotcrete work based on pics on their website, but when I would call, they would only tell me that they subcontracted on an as-needed basis and would be happy to manage our job for us.
In a few cases, I managed to find the names of some of these subcontractors and mostly found that their motivations were similarly frustrating. Keeping the landscaping and pool companies happy was their primary motivation and my side job was just a distraction. I actually had a few of these companies out to look at my site and give me a quote. But then they were all solidly booked and said they would keep me in mind if a bigger job every canceled on them and they suddenly need work. In other words, I could be lucky enough to be their back-up plan, but would get very little notice.
And then I somehow got the name of S.A.M. Pools. I can’t even remember the chain. I have several contractor friends and I think one of them gave me the name of a guy who has quit the business, but gave me the name of another guy who knew Scott at S.A.M. Pools. When I had started my search a couple of years before, they were a pool plastering company, and it was only in the past year that they had bought a gunite rig. Even now, a year after doing my job, their website (much better than most) still doesn’t mention a single word about gunite.
So, when I called Scott (the “S” in S.A.M. Pools), he came out right away and gave me a quote. We considered it, did some math, etc. and found it was on the high end of the range of what we had paid for shotcrete, but at least it was in the range (our Shotcrete prices had varied wildly). The quote also said he could start the following week. I texted him over the weekend to say we accepted the quote. I just went back to find my exact words… After saying I accepted, I said:
He immediately phoned me, seriously insulted because he had already told me that he would be available and did I not think that within a week of giving the quote was soon enough! Of course, I apologized for assuming that he was like the others who had given me quotes without any plans to actually show up. We coordinated based on weather and time required to get the supplies delivered and booked a date for gunite on Friday that week.
This was after about 11 weeks of waiting for the previous shotcrete crew, so I was nervous all week that they would finally become available and I would need to decide to decline one or the other. I needn’t have worried. After the gunite was up, I texted the shotcrete crew to tell them they didn’t need to worry about doing that tower any more because it was done. They wished me good luck.
Differences between Gunite and Shotcrete
Gunite and Shotcrete are more similar than different, but lets talk about the differences. I have now had two crews work on my site, the first was shotcrete and the second was gunite. Primarily, you should care about the fundamental differences between the methods. However,there were also significant differences between the crews that I personally worked with. I’ll try to keep those separated. The crew stuff belongs here in the post about my own personal experience. The fundamental differences in the method belongs as one of the technical posts.
The Crew
Let me start by saying that I appreciate any crew willing to come out and help on my project. This goes double for something as physically demanding as shotcrete. In full disclosure, I should note that I have since had a falling out with the previous shotcrete boss because I wouldn’t remove the Youtube videos after many negative comments came in (the internet is such a friendly place), so I won’t mention any names here and will try to be as fair as possible (actually, I am being very generous).
The shotcrete costs were wildly erratic and often doubled the quote. The unpredictability was very stressful and always ended up much more expensive than I budgeted for. In contrast, the gunite crew gave me a quote and it was exactly that price at the end.
Communication between jobs and during the jobs was so much better with the Gunite crew. Messages were promptly returned with phone calls and rapid resolution, etc. The only thing that wasn’t rapid was sending us the bill. Meanwhile, the shotcrete boss left me with hundreds of ranting text messages. Some optimistic or fact-based, others swearing at me and calling me an idiot, and then followed by more positive ones and then almost all very negative after we switched to the gunite crew.
The quality of the work was the biggest difference. The gunite crew used measuring tapes, cleaned up their messes, and produced smooth flat plumb walls. In contrast, I never saw the shotcrete crew measure anything or use a single level, they left (literally) tons of mess for us to clean up and the walls were very rough despite my many pleas to have them smooth things out. I don’t know what portion of the low quality was due to apathy vs skill level, but, in theory, a shotcrete crew could get the work just as nice as the gunite crew if they had the skill and wanted to.
The Method
Differences such as the compressive strength or durability of the concrete (its all about the mix), the slump of the concrete, the pace of the work and even the weight of the hose are technical differences compared on this technical page.
The Galery
And here are some pics…
They dropped off supplies and equipment the day before. This got me excited 😉
This part of the gunite pump works like a geneva drive from a film projector, except it moves pockets of mix instead of frames of film.
Bert was great with the Skid Steer, running it around at high speed.
Joe keeping the rig going
Walls were done one level at a time.
planning the ladders for the next section of tower
Back wall of the kitchn
Behind the stairs after the second pass
Mezzanine after the second pass
second phase on the tower
Cleaning up the tower after the second pass
Master Bedroom eyebrow after its first pass
Eyebrows after a pass or two
Eyebrows after the second pass
Mezzanine during the 4th pass
Michael picking up the camera and taking a quick pose
They got the office done before the weekend. I kept it wet to improve the cure.
Office completed, you can see all the rebar chairs on the inside
Behind the gap between the two eyebrows
Almost done the eyebrows
The final edge of the tower
All done
Tower pass thru
Looking up in the finished tower
The wide angle camel unravels this tower
Carlos after finishing up
A look down into the tower. In the original plan, all the concrete ribs were supposed to be a few inches further out so the tower would have had a smooth inside. Oh well, mistakes were made and the house is a little smaller now 😉 All due to rushing on the day the crane was there. I’ll work some sort of book shelf into it and it should look fine.
Carlos enjoying the view after he was done
They were able to clean up this nice ledge so I can set my quad deck slabs up here easily.
You can see the wire that I tied at the right height. Then I asked the crew to trim off the concrete along the wire.
Jimmy after shoveling out this big pile of rebound and trimmings
Taking away the rebound with the skid steer
Cleaning up with the skid steer
Bert dumped the rebound on my concrete waste pile on the back side of the garage
After they were done, the rain picked up, which was just perfect for curing the concrete
A few weeks later, I began to strip off the forms
A few weeks later I started to tear off the forms.
While prepping the tower and mezzanine, we also worked on the bedroom eyebrows. It was just too big for one video. More on what “bedroom eyebrows” are after the video.
The Video
Bedroom Eyebrows
Bedroom eyebrows are not some sort of double entendre that only earth sheltered home builders get after a long hard day. They are simply the structures we used to keep dirt off the windows while still having a hilly appearance. You see them in Peter Vetsch earth shelters all the time. However, I suspect (from construction photos) that Peter’s eyebrows are big heat radiators that drastically reduce the thermal efficiency of his buildings. I wanted to avoid that problem, so I needed mine to be thermally isolated from the actual home.
I did this by separating the shotcrete into two phases. After completing the bedroom shotcrete and waterproofing it, I added a saddle of 4 inch thick XPS Foamular 250… This is the kind that can handle 25 psi of pressure and is intended for burial. Above the XPS, I build another rebar framework and put shotcrete over that. Or at least, that is what I wanted to do.
In more practical terms, I used tapcon screws to mount treaded wood 2x4s directly to the bedroom shotcrete. Then I drilled holes in the 2x4s to hold the rebar framework… So there is a little edge all the way around where I sacrificed long-term insulation for a more buildable structure. I have since considered other ways I could have done this and may do it differently if I ever had to do it again, but I don’t think the performance will be too bad. Certainly still better than a more traditional house.
The Gallery
I am tired of typing, you may be tired of reading, so let’s just skip to the gallery.
Various stages of progress
Bedroom south eyebrow rebar
John helping with the rebar above the hall roof
Sherri and I often have end of the day discussions that get caught on timelapse
David was almost 13 and going thru a bit of a goofy phase
Another goofy David Pic
Even Sherri decided to get in on the goofy poses. Maybe it was the heat?
Hunter leaving me an Easter Egg to find. This is the appropriate punishment.
Not to be outdone, Michael also made a number of goofy pics
Michael again
Sherri and David posing for the time lapse cam. They like to leave these little Easter eggs in there for me to find.
Lots of turtles around
Office Apse viewed from the roof of the garage. This big area was going to get a bit water tank, but I ended up deciding it wasn’t worth the money.
Kids playing on the office apse jungle gym
After putting the french drain for the office apse, this time before the shotcrete so we wouldn’t have to deal with any mess
Kids playing on the office apse jungle gym
The eyebrow for the master bedroom apse was the most elaborate