Its a short one this week, and the end is rather abrupt, but here it is anyway…
Why a Quonset hut?
My house design is an experiment with a variety of different arch forms. Since it is a self build, I kept most of my spans shorter than 15 ft. The exception is the garage. I wanted a 3 car garage for practical purposes and decided to use a Quonset hut to form the wider span.
The quonset hut could probably support a significant earth load, if it were carefully distributed, etc. But in my design, it is really just fancy formwork to hold up the rebar and shotcrete that will actually support the earth.
My build also required a workshop to build the other components, and the Quonset hut is something that could be erected quickly, early in the construction, and provide that place. I have used it to weld steel arches, store materials, and most importantly, to form my large concrete ribs.
Why build it in two stages?
The rib forms needed to be built on a large flat surface, out of the weather. But we would also need to use a crane to move them to where they needed to go. The ribs weigh 5000 lbs each, so I couldn’t roll them out across the gravel or dirt. Instead, I needed to keep them on the slab, but also needed open sky above them for the crane.
The solution was to build only 2/3rds of the Quonset hut on the slab floor. I could use that sheltered space at the back to form the ribs. I would then jack them up and pull them forward to the open 3rd where a crane could lift them up and over to where they needed to go.
When the crane came out, it did lift them straight up and over, but I noticed that it actually had a telescoping arm. I asked the operator and he said that he could lift them up and pull them out of the building if I finished it…
The ribs were taking me a long time to make and closing off the building would save me a lot of hassle, so that seemed like a good idea. It had been almost a year since the first 2/3rds were erected.
The final 3rd
My parents came down to visit and to pick up their camper. Anyway, it was windy and we didn’t want to try erecting Quonset sections with just the three of us. However, that is a good number for assembling the steel arches, so we spent most of the afternoon doing that.
The following week, I put out help requests on Facebook and at work. The first few days, I was worried that I wouldn’t have at least 4 people there at one single time. By the end of the week there were lots of people volunteering and I was buying a few extra half inch sockets and wrenches so there would be tools for everyone. One co-worker even volunteered his whole family of very capable teens.
The steel ribs went up very quickly. 7 in under two hours. We were actually done before the Pizza lunch I ordered arrived. No worries, we had other work to do (not captured on film).
Because these new steel arch sections were were bolted to the rest of the Quonset hut, which was already bolted and concreted to the slab, and because they were very heavy, I wasn’t too worried about the new section blowing away. With 13 people working in parallel to bolt the sections together, I didn’t want to interrupt that flow and make everyone stand around while I drilled and bolted the steel sections down. I figured I would come back and take care of the anchor bolts next time…
However, by the next time I went out there, I found that the wind had lifted the front third of the Quonset out of the groove. We ended up wasting several man hours and a lot of sweat getting it back into place.
I should have known better because this is a pretty typical fluid dynamics problem that I had to do several times at school.
Another “mistake” that I pretty much accepted was that my building was a little longer than it should have been and ended up hanging over the edge by a few inches. I ended up cutting that off so it wouldn’t get in the way of the end wall, but that is another story.
Before we could pour, we had to install the pex tube for the radiant floors, build a perimeter form to hold in the concrete, put in plumbing, electrical conduit and duct work, and generally clean up any mess from the previous steps.
While we had the pump truck there, I also wanted to pour a couple 7 ft tall columns, so we also prepped those. We also poured a section of ICF wall, but I will save that for another post…
After it was all over, we had to remove all the forms. We gave the concrete a couple weeks to cure (and gain strength) and then we removed the scaffolding and shoring.
You can find the Video here:
Experienced workers and new technology
They workers are used to pouring concrete on stable ground, so they were quite nervous about pouring on the ICF forms. They started out walking very carefully and there was a lot of nervous laughter. I made sure to pass along the pour instructions I had received from the Quad Deck installers. After the grooves were filled, the guys appeared to forget what they were standing on and began stomping around as usual. We had no problems with the Quad Deck system. Everything held up and there was only a little bleed water in the basement.
The blow out
During the column pour, the weight/lateral pressure of the concrete blew out the forms. To be clear, these were my column forms, that I built, not the Quad deck forms. My heart sunk as concrete spilled into the basement.
Next thing I knew, the guys from Dysert concrete, who were working on finishing the slab, jumped into action and helped strap the form and re-level it. This was really going the extra mile because they were really only there to look after the floor. They also went another extra mile and helped me scoop some concrete out of the basement. When it was all over and guys were packing up, I tried to give them some cash for their extra efforts, but they wouldn’t take it. If you are in the SE Michigan area, I recommend these guys.
In contrast, the pump truck operator (not my usual guy who is very helpful, so I won’t blame the company), clearly did not want to be there. He was grouchy from the start, perhaps not a morning person? When the floor was finishing up and I told him the columns were next, he complained a lot because he thought he was only there for the floor. He threatened to charge me extra. At that point, we were not even half way thru the minimum 4 hour window that I had to pay for. Also, I had specified (in writing) the volume of concrete and listed the columns and the ICF wall when I booked the truck. I didn’t bother arguing all these details with the driver, but I simply ignored his threat and told him it needed to be done before he could pack up.
Amateur legal note: If a contractor tries to change the price part way thru a job without sufficient justification, you can safely ignore the threat. Legally, if it would be even more expensive to switch contractors at that point, the threat of a work stoppage amounts to extortion and puts you in financial duress to agree with their unjustified price increase. In this case, I didn’t verbally agree to the extra charge, but I did tell him to continue on, which could be considered implicit agreement. However, even if I had agreed verbally, or in writing, I would still be able to contest the extra charges in court later due to financial duress making the amended agreement invalid. In order to increase the cost mid project on a fixed bid, the contractor would need to prove that the scope of the work increased significantly beyond a reasonable expectation. For instance, my septic field guys found a 1940’s garbage dump almost as soon as they started digging. The health department got involved and ended up raising the cost of the installation by about 30%, which I agreed to and paid without an argument.
When the columns failed, he was even more annoyed at the extra delay and kept saying he had another job to get to. I reminded him that he had been there less than half the minimum time I was paying for. A moment later, he started dumping concrete on the sand, we suspect it was intentional so he could leave. Sherri got mad and yelled at him until he stopped. However, as a result of the waste (intentional or otherwise), we did not have enough concrete to finish the ICF blocks in the north wall, but that is another story.
This pic is just one the time-lapse caught as I was moving the camera. It shows Sherri trying to clear the dumped/wasted concrete off the footings. Definitely not princess work, but I never asked her to do it… I was running too much to even think about it, but she separated it into smaller piles that I could move after it hardened, so I am glad she did.
You can see that a few of my friends in this and other videos and in the gallery below. Some of them actually like this sort of work, others come out and help anyway. I appreciate them all.
Working with friends makes the work go faster and the day fly by. Some of them have also taught me some good tricks based on their respective experience, or mentioned tools that would make the job easier. I will definitely have to have a big party when this thing is all done.
In the video, you might have caught that the pressure test dial didn’t hold the pressure when I filled it. I ended up using some dish soap from the camper to find the leaks. I had one easily fixed leak in the manifold, but most of the trouble was with the Shark Bite connections. Basically, I had not left enough extra length to reach down to my manifold (oops), so I needed to connect some short bits to make the final stretch. The SharkBite connectors are individually expensive, but easy to use without any tools, and I only needed a handful. However, try as I might, I couldn’t stop some of them from leaking. I talked to the plumbers (who use Pex for everything) and they said they prefer the crimp connections. I figured I would eventually be putting in a bunch more radiant, so I decided to spend the money on the crimp tool and it easily sorted out my issues.
I had long planned to insert 1 ft long glass rods thru the Quad deck to let light thru in both directions. When it came to the layout, I went with the points of a simple Fibonacci spiral, centered in the room and leading around to a spiral stair case around the corner. Later, I can etch or mosaic in the actual curve if I want to.
These are sorts of fun little extras that make building your own home fun.
To keep the glass rods from being pushed thru the floor by the workers stepping on them, I screwed boards up underneath to hold the bottoms in place. This is why the lights turn off just before the pour in the video.
The scaffolding that I rented has been stacked nicely and ready for pickup for more than 4 months with no responses to my monthly texts to the builder to come and pick ’em up. You will see it in the background of various other videos ;^) It was actually quite labor intensive to remove it from the basement, so I hope the builder appreciates that that free labor. I wonder if I could surprise him with storage fees? I had to move it again recently.
Quad-Deck is a product sold by Quad-Lock, an ICF (Insulated Concrete Forms) company. It is basically a flooring (or roofing) system that uses polystyrene as a form for concrete. The panels click together and include steel beams so they can span greater distances (with less shoring) while supporting the wet concrete. The concrete hardens to form a continuous floor over the panels and the panels are left in place as insulation.
My unique earth sheltered home design includes a basement. This increased the height of the walls holding back earth. Structurally, I needed my floor to be a sheer plane that would prevent the earth from pushing in those walls by transferring the lateral loads right thru the house into the dirt on the other side. The resulting compression would be well handled by a concrete floor. I just had to find the easiest way to build one.
I could have built a deck out of wood or steel panels supported by bracing and just poured concrete over that. There are modular systems that work pretty well and are cost effective for rectangular buildings, but my curved shape would make it quite difficult and expensive. Also, those systems generally produce a uniform concrete thickness, which adds to the expense.
ICFs had the advantage of being easy to setup and easy to trim. They also use less concrete because they can form that stronger IBeam shape. The insulation is also perfect for my in-floor radiant heating and helps with more consistent indoor temperatures and reduced sound transmission.
Unlike ICF building blocks, there are very few companies that make this sort of ICF floor system, just about the only other company with a similar product is “Lite-Deck”, but they had no distributors in my region. AMDeck is a similar product that only comes in short pieces (32 inches long) so you don’t need to order custom lengths, but you need to place the steel joists separately and then place the Insulation over them and it just seemed like more could go wrong.
1) The quad deck panels are cut to length (according to a cut sheet I provided) in the factory and shipped to the site.
2) The installers (in my case, Dan and Brian), started by setting up scaffolding spaced across the floor. Beams were placed across the scaffolding and the scaffold legs were adjusted to level the beams across the space.
3) My curved walls required both ends of every piece to be shaped to fit. This was done with a measuring tape and a saws-all. Occasionally a big cutting wheel was used.
4) Each piece was pushed up against the previous piece before being screwed in place so that they would be held tightly together. The screws were “toe-nailed” thru the wood shoring and into the steel reinforcement.
5) Spray foam was used to seal the gaps between the top edge of the wall and quad deck material.
6) Rebar was placed in the channel and across the quad deck according to the drawing. Rebar chairs were used.
7) A perimeter form, plumbing, electrical, HVAC, radiant floor PEX, etc. were added later (next post).
In my region, it seemed like I pretty much had to go with QuadDeck if I wanted this sort of product. To make matters worse, QuadDeck only had one single installer in my region. I asked for a quote on both the quad deck and the ICF walls of the garage. The wall quote from this builder was not even in the top 3 and several times more expensive than doing FoxBlocks myself. But they were the only quote for the Quad Deck, and I thought special bracing was needed, so I decided to go with them for that portion of the build. The quote was for “Quad Deck install, labor and shoring rental.” I called for further clarification and was told it would get the quad deck ready for the pour, but did not include the actual concrete or labor to pour and finish the floor. I would need to call a separate contractor for that. The price was high, but acceptable for a company with specialty experience and equipment, so I put them in my estimate.
Later that summer, after back-filling around the basement, it was time to get the quote updated and call the crew out. I sent in pictures of the basement (including zoomed in shots of the edge of the wall), along with a cut-sheet and images from my 3D model, calculations from the QuadDeck manual (it is a pre-engineered product), etc. They updated the quote, but said they wanted an engineering stamp before they would start work.
My engineer had retired (still young, but wanted to stay home with his kids), so I contacted the builder’s engineer. He was willing to check and stamp my work and he was very affordable, but he was also very old (eighty something) and only worked face to face (no computers). I would need to take him drawings and he would hand calculate and stamp them if he approved. There was a funny telephone episode where I was asking him his address (so I could google map it), but he just kept repeating how to get to his office via landmarks. Before I could get out there (he lived 4 hours away), he had a stroke and retired. I didn’t want to pay a new engineer to learn about QuadDeck, so I began a search for someone with experience. The builder wasn’t much help. I even called quad-lock company headquarters and they just forwarded my request back to the builder. I called QuadDeck back a few times and asked for other regions until I eventually found an Engineering company in the southwest that was licensed to stamp a drawing in Michigan. It ended up adding a surprise $1200 to my estimated cost, but may have saved me some money because my version would have used twice as much rebar (I was being conservative with the Quad Deck load calculations).
I still couldn’t schedule the builder to come out. I tried to go around him, but it turned out he was also the only builder in the surrounding 4 states. He had a monopoly and ran his business that way.
Eventually, we got the quad deck panels ordered. I knew it would take weeks for my order to be cut and then delivered. They were supposed to call me with a delivery time 24 hours in advance so I could organize to unload. Instead I got an annoyed call from the driver at 6:00 in the morning wondering why there was no one at the building site. Surprise, my 10-year-old and I hopped in my car and drove the hour out to the property, but there was no way to organize any other help in that short time. When I got there a little after 7:00 AM, there was a large 18 wheeler trailer full of QuadDeck planks waiting for me. It was the closed in kind with big double doors at the back, so I could not unload with my fork lift. The panels were stacked to the roof and would need to be removed by hand, slid out one at a time. I had to get a 13 ft ladder just to reach the panels. The driver was impatient, so David and I got to work without setting up the camera. The driver complained that we were taking too long, so I told him that he could have called to let us know he was coming (as he was supposed to do) or he could help. He helped a little with a couple of pieces that David could not physically lift, but generally speaking, he just paced back and forth. Eventually we got them all out of the truck and the driver shook David’s hand before he left. I think he was impressed with David, but was also still pretty annoyed with me for not having a real crew.
We used the SkidSteer to move the blocks up behind the house and stacked them and covered them with a tarp… And then waited. Every few weeks, the builder made up some excuse and moved the date back. The list of back and forth texts is quite ridiculous. Eventually, 3 months later, he said he would be able to slot me in before the end of Sept (one week away). He asked if I had the rebar on site, I did. He asked if I had the full list of building materials he needed… I had no idea what he was talking about. He sent me a list, which added up to $1700. Surprise! The list included 4×6 beams, 35 lbs worth of screws, 3/4 inch plywood, 2x4s, 2x6s, a case of spray foam, anchor bolts, etc. I called him and asked if he was planning to build the shoring? I was obviously annoyed, which annoyed him and he said we could just call off the whole thing and I could look for another builder.
Of course, I already had the material on site and he knew he was the only builder within 1000 miles that had ever installed this stuff before… I gave in and we proceeded. He then told me that his quote did not include the perimeter forms that would also be needed before we poured, but he could do that for an extra cost. I was so annoyed, I didn’t even want to discuss the extra costs or argue that he never mentioned this before, so I told him I would take care of that myself.
I asked how many days it would take for what was included in the quote, he said 6 or 7 days for a crew of 3 people.
Anyway, as you can see from the video, it took 1 day just to set up the shoring (which turned out to be regular scaffolding and my 4×6 beams, leveled). Then 2 days to put in the quad deck. There was also a short 4th day of just a couple of hours when they finished the quad deck off and were gone by 9:00 AM to work on pouring some other wall somewhere else. Then the last day was just putting in rebar and spray foaming. The main boss never even made it out to the property.
After the job was done, he sent a final bill that included about 2000$ extra costs for “unexpected extra work” including putting in rebar and spray foam and “gasoline for the generator”, etc. I was sick of the surprises and fought him on most of it. He kept asking me to “meet him half way”. Instead I went thru my emails, texts and time-stamped-timelapse photos and wrote up what could easily have been a trial defense. For instance, I pointed out that he had estimated 7 days for 3 people, but got the job done in 4 days with mostly 2 people, how could he justify “extra costs”? He eventually gave in on most of the bogus extra charges, but still got his “36$ for gasoline for the generator”. I just wanted to move on.
Then he hit me with the scaffold rental. He wanted several thousand for that. I told him that his quote said “labor and scaffold rental”. He said that was just the first 2 weeks, I had kept the scaffolding for 3 weeks longer than that to finish getting it ready for pour and then leaving the scaffolding in for 2 weeks while the floor set. He wanted $15 per unit for those 3 weeks. I eventually agreed, but then he defined the units as half sets (so twice the cost). Arg! long story short, I ended up paying an additional 810$ to rent that scaffolding for 3 weeks. For perspective, I paid $1200 to buy my other 5 sets of scaffolding, and that included 6 decks, 8 wheels, outriggers, a grouser bar, etc.
Anyway, as much as I liked the idea of QuadDeck, I would never work with that builder again. I have some quad deck left for the roof of the mezzanine. I plan to install it myself.
Bonus fun facts…
1) The scaffolding that I rented has been stacked nicely and ready for pickup for almost 4 months with no responses to my monthly texts to the builder to come and pick ’em up. You will see it in the background of various other videos ;^) It was actually quite labor intensive to remove it from the basement (next video), so I hope the builder appreciates that that free labor. I wonder if I could surprise him with storage fees?
2) At the end of each day, the guys did a great job cleaning up the site. They used a leaf mulcher to suck up and bag the little broken bits of Styrofoam so they wouldn’t blow all over the place and they carefully stacked the other trash.
The original quote was about 4$/sqft for quad deck materials. That turned into 6$ by the time we placed the order (including freight). Then another $7/sqft for labor and shoring rental. I also budgeted about $1 for rebar and 2$ for concrete, plus 3$ for labor to pour and finish the floor. Then I had the surprise of just over 1$ for engineering plus just under 2$ for extra materials (some of which I was able to return unused and much of which I will reuse elsewhere in the build). Then, finally, that ridiculous “additional” scaffold rental at the end, which divided out to just under 1$/sqft. That comes to about ~22$/sqft by the time we were done. Quite a bit over-budget, but survivable.