These blocks are basically reinforced styrofoam lego blocks that you can build into a wall and then fill with rebar and concrete. The styrofoam is the formwork during the pour and stays in place as insulation for the life of the building. They are a fantastic way to build.
This week, I attended a training session for “Fox Blocks” ICFs. I had already watched all the videos on Youtube, but I wanted to get some “hands on time” before I started on my own build in the spring.
There were quite of lot of guys there learning to install these ICFs. Many had big jobs coming up soon. At least a couple had subcontracted other crews to do ICFs for them in the past, but wanted to do it themselves next time. One crew had brought house plans and were discussing how to adjust the plans for easiest ICF construction. There were lots of questions (it went for ~6 hours instead of 4).
During the training, we got to practice clipping the blocks together, cutting them, etc. We roughed out a basic window together, but we didn’t take it as far as putting in the window bucks and buck supports. It would also have been good to get in some hands on practice setting up the bracing. Of course, we couldn’t pour cement in the shop, but that sort of experience before my actual job would have been great. There was class room time to cover the details we couldn’t cover in the shop and I will get a card saying I am certified as a basic installer…
I need to buy a few basic tools and put my order together. I could do it in winter, but I plan to wait for spring anyway.
Why FOX Blocks?
I put together a big spreadsheet comparing all the quotes I got from various companies and dividing the total costs by square footage, etc. I found that I could get Fox blocks for less money and the install looked easier due to some clever features of their particular design. I also liked that I could purchase the blocks from the hardware store (Menards) and install them myself. The more I researched, the more I was convinced that the Fox Blocks company was growing so well because they made the best blocks in the industry. During the install training, the instructor (Ken Williams) also pointed out a number of other design advantages. As a bonus, I learned that their blocks are made from all pre-consumer recycled content (their parent company makes frozen food containers and needed something to do with the trimmings).
Unfortunately, they don’t have a “Quad Deck” alternative. For that, I will still work with Quadlock.
In other news, I put in some rough stairs to more easily access the basement and I will post about that separately. I also got a drill press and “fabricated” the bases for my steel columns; again, that will be a separate post.
Some of you may have noticed that I used a new timelapse camera for this video. I got a GoPro 3 White for my birthday and this video of the training was my first footage with it. I guess I will record the next segment at the property with both cameras and talk about that in another post. The much larger wide angle lens should make it much easier to get interior progress shots and a wider outdoor view of the construction.
Welcome to 2015… Hopefully, the year we get most of this earth sheltered home build done.
At the moment, things are pretty cold for building with concrete. There are ways to cure concrete in freezing cold weather, but the additives often reduce strength and/or corrode the reinforcement, so I am mostly working on planning. I have also pretty busy at work and got going again on my MBA, I am doing a business law class this semester. I go out any time the weather gets above freezing, but there were a couple weeks over New Year’s when I didn’t make it out to the site at all.
I guess my neighbors got a bit concerned about my seemingly lackadaisical approach to construction, so the neighborhood association wrote me a letter reminding me that I only have a year to get it done. They also reminded me that I have some legal liability if anyone (particularly children) get hurt on the site and asked me to fence it off. I wrote back that my mortgage company also wanted me done within a year, but has much bigger financial teeth than the association, so they don’t need to chase me about it. I also agreed that the construction fence was a good idea, at least from a legal perspective.
I went out to the site and just strapped some of that cheap orange construction fencing directly to the steel studs around the basement. More importantly, we took down the tempting scaffold tower so that we would be a less “attractive” nuisance to our neighbor’s children. I also put up a bunch of “Warning, Construction Site” signs. They are more for legal purposes than anything else.
Around about this time, I also started to bury my footings. I am sure that seems strange, so I put some fancy power point graphics into the video for a little extra explanation. The short story is that we need to fill in a couple hundred yards of dirt around the footings before we build the walls so we can use the skid steer instead of hand tools…
I had planned to bury the entire main level footing, and then hand excavate the top of the footing again so I could start bolting the steel to it ahead of the spring. But the ground is just too frozen to work with properly, so I am putting off that task until spring and have switched to focusing on tasks that can move forward, such as mounting the hardware for the basement stairs and central tower structure.
The video on those other tasks will come later, but here is the back fill video:
Even though the Quonset hut was bolted down, the steel arch shape hut does not really achieve its design strength until it is grouted in place. With winter coming, I was under pressure to get it done quickly before the temperature dropped and the snow storms rolled in.
It is actually possible for concrete mix additives, such as plasticizers or accelerators, to accelerate the curing reaction so it will set in colder weather, but, the SteelMaster Quonset installation manual warned that such mixtures may be corrosive. Calcium Chloride, specifically, is known to release steel corroding chloride ions and should never be used with rebar, let alone the thin 20 gage steel of the Quonset hut.
The weather was generally too cold by that point, so I had bought a couple propane heaters and decided to get started before it got any colder. But then the weather changed and the forcast was for several days with highs above 50°F and lows above freezing. I headed out to the property to take care of this job…
My grout mix was a simple 2:1 ratio of sand to Portland cement. I bought the 94 lb bags of Portland cement for ~10$ each. I already had lots of nice clean sand on site (my hill is made of it), so I just used the skid steer to bring some over to where I was mixing. Creating the mix with my own sand saved me hundreds of dollars over buying pre-mixed bags of cement. The third ingredient was water… I have no access to water on the site, but I had brought a number of 5 gallon buckets full of water with me. I did not use any additives.
I have often mixed small batches of concrete in a mixing tray or wheel barrow for odd jobs around the house. My biggest manual mix had been a couple sidewalk squares. But in this case, I knew I had about ¾ of a cubic yard to mix, and I knew that I would have lots of other concrete and stucco mixing jobs, so I decided to buy a mixer. I had been keeping my eye out for one for a while and ended up getting a decent 3.5 cu. ft. ¾ horse power electric cement mixer, on sale for 40% off. The majority is metal, but the barrel is a strong thick plastic that won’t rust on me. I paid about $200 dollars, but I am sure it will be worth it. Just the time it saved me on this one project probably made it worth it to me ;^)
Once I was all setup, I used a shovel to measure out the mix and then added water until it reached the right consistency. Ideally, the concrete should be sticking well to its self, and not to the mixer. However, until it was fully mixed, I was using a small shovel or the trowel to scrape off the sides and keep everything mixing.
I used a 3 gallon bucket to carry the mixed grout to where it was needed.
With the shorter days, of November, it wasn’t long before the sun set and I was very glad to have my work lights… However, the work-lights and mixer were quite a strain on my generator and it nearly stopped a few times, leaving me momentarily in the dark.
Near the end, when I was worried that I might be a little short of concrete, I started adding some scrap rigid insulation as a volume filler. I probably should have thought to do that from the start.