Well, here's the second year of the house project. I flew back on Sunday May 5, and it's taken me until the 30th to get enough done to feel it's worth a new photo. The interesting news is that we've decided to change from the TJI Joists specified in the architect's drawings to Hambro's D500 system of concrete and steel joists. This will make the walls about 8" higher for each floor to accomodate the 16" height of the steel joists that are appropriate for our project. While this wall height will permit an 8 foot ceiling with gypsum board fastened underneath the joists (which I'm sure a bank will like), rather than using the gypsum board, we'll likely paint the joist steel with a fire resistant intumescent paint similar to A/D Firefilm III and stain the bottom surface of the cement slab above it, like we plan to stain the top surface of the cement slab for the floor (but not necessarily the same color). This will have the combined benefits of 16" extra air space overhead, no installing or mudding gypsum board overhead, and a built-in easy place for hanging holiday decorations. At our request, Hambro will be designing the roof slab to be strong enough to have a "green roof" type of protected membrane roof system in a manner similar to the one described in this PDF from Dow Chemical Co., who I'm sure would like to sell us styrofoam boards to insulate that roof. As a co-worker of my sister's pointed out, a garden on the roof will be much safer from hedgehogs. The Rastra block have been going up fairly nicely, and we'll likely be done with the walls well in advance of the arrival of the steel joists. The curved walls make for bigger gaps between the blocks (even with having beveled them), and we're using a lot more of the foam glue than anticipated. I bought Powers Triggerfoam for the next bunch of glue. It was recommended to me at the former Rastra plant in NM, and it has product fire & health safety information that is fairly easy to learn about online.


Now the walls that will be completed before we bring in the steel joists are done. As the result of a choice we made about the garage footer, the forms for the garage frost wall need a vertical spacing of 12" instead of 15" for the concrete. We ended up using the beveler to cut the middle out of the blocks. Sadly, the small chain saw we had purchased for trimming edges with the beveler wasn't up to the task, so I drilled the appropriate holes in the bar of the other saw we have and used it.

Chopping Reassembly

This is working, but the result is a lot less consistent than it looks when the cuts are first made. We've decided that frost wall is going to look its best after we've buried it. Here's the state of construction on June 19th. We've put some pallets, insulation boards, and tarp over the stairwell so that we can keep the rain off some hand tools. Previously, we had been using my old Bronco (It's in sad looking shape, but where's the first car you ever owned?) for that job. The stairwell is much more spacious and convenient. As I type this it's June 25, and the fireplace support you see laid out on the basement floor is complete up to all but the top row of blocks. The top row is waiting until we mark the inside of all the exterior walls with the laser level. We'll be cutting about 4" off the inside of the exterior wall forms so that the inside of them doesn't interrupt the floor concrete from joining the wall concrete. We'll be similarly modifying the frost wall in the garage. The joist layout drawings came from Hambro for approval last Friday, so hopefully we'll have the joists here in about seven weeks.


I had a phone conversation yesterday (August 2, 2007) from which I learned that the steel joists will arrive Monday, August 27. I'll be at home in WA the week before, ostensibly to activate the replacement for my expiring debit card, but I'll also be attending a memorial for a friend who died during the end of May and visiting with a nephew I haven't seen in a while. Back at the start of June, the honeybees living in the old house swarmed again, providing an example for the words I read in Wikipedia that colony collapse disorder isn't a problem for feral or organically raised honeybees, just for commercial bee farms where, coincidentally, the bees are fed protein supplements.

Basement Basement

Here's a photo from July 14, 2007 of the 6" diameter holes I drilled for connecting the basement floor to the walls. In the background, you can also see the top of the fireplace pad support and the cut I made on the inside of the basement wall Rastra where the bottom of concrete for the floor above will be.


Then, we used some 2x10s to cover the holes and contain the concrete. The cross pieces are held in place by pieces of 1/4" all thread going through the middle of the nodes in the Rastra that form the gaps in the concrete grid. This construction looks typical of installing a ledger beam for holding up floor joists. The difference here is that the 2x10s will be coming back down once the concrete in the walls has hardened and the garage floor will be directly supported by the Earth. The landing at the top of the stairs will be supported by the walls, however. The new things visible in the background of this photo are the top ends of the pieces of aluminum plank grating I got for making the treads of the basement stairs. As there's no other access to the space behind those stairs, my sister wanted them to be able to lift up, so I'm welding up a stairway out of aluminum. It'll be nice, I think, to use the familiar construction methods from my work on part of the house here.

Basement Basement

Well, as you can see, the physical construction is going pretty slow right now. Once the floor joists arrive, things will speed up a lot. We'll be racing against Wintertime.

September 12, 2007
Here's a report of some of the further progress. I'm being a little bit lazy and linking some of the photos to text rather than to smaller images. Here's a photo of what I made to anchor some coupling nuts into the wall. I wanted to make the wood of the rough bucks removable, in case it got damaged during construction or a desire for other wood were to occur in the future. Here's a photo of a few of the anchors in the wood standing in for the bottom of the door buck in the doorway from the garage to the basement. The steel joists arrived in good order on the morning of August 30th. There was a little bit of confusion between six of our beams and six belonging to someone else, but I called that day, and a truck from Quebec arrived the next afternoon dropping off the correct beams and picking up those that arrived by mistake. We carried the joists for the basement in on the 30th and the following day started building the form walls we had left down in order to permit that carrying. Here's a photo and here's another taken part way through lifting one of the joists onto the newly built form wall. One of the nice things about the Rastra form blocks is their compressive strength, which allowed us to stack up scrap pieces in order to lift the ~200 lb joists in smaller increments. Finally, here below is a photo of the basement I took on September 9th.

Basement Sept 9th, 2007

Here's a few more photos of setting up the bond beam and putting the beam over the doorway in the partition wall in the middle of the basement. After I thought we were about ready, I started vacuuming out all the dust that had gone down into the forms. Cutting out the nodes for the bond beam especially let a lot of it go down there. The big end of a piece of 1" electrical conduit fit around the leaf blower nozzle that came with the Craftsman Blower Vac, and I used that to reach to the bottom of the forms for the vacuuming. It worked best without direct sunlight as the flashlight that was necessary to see the bottom couldn't compete very well when the sun was out. The vacuuming took more than three days. As I went along, I did final placement of the vertical rebar, trying to use it to help hold the horizontal rebar more closely to the middle of the holes. The challenge of doing this in the curves, led me to the understanding that it would have been impossible to do this sort of curve construction if the curves hadn't been circular sections. In turn, this understanding led me to consider Autoclaved Aerated Concrete as an alternative to Rastra for building my own house later on. When using the common construction method for AAC, all horizontal concrete is in the form of bond beams, so horizontal rebar can more easily be properly placed in non-regular curves. Once I had the vertical rebar placed, I wire tied the extensions to it for tying the basement wall the the next wall above. When that was all done, I went back around and wire tied in the bond beam rebar, tying it to the horizontal supports to control the spacing, and tying it to the #6 vertical rebar in those places where two of them occupied the same hole. In the meantime, I had purchased one of Oztec's Rebar Shaker concrete vibrators as, not having contractor's insurance, we were having trouble renting one. Here's how it all looked on the morning of October 7th, the day of the basement wall pour.

The basement on wall pour day, October 7th, 2007

During the pour, Steve went around placing the concrete, and I followed behind, vibrating. Raimona, not wanting to work near the tops of the walls, did everything on the ground, placing and smoothing the concrete for the floor in the stairwell, filling the bottom of the window frame of the escapement window, and trying to make up for our lack of cleanliness preparedness. The wall pour was successful in every way where we were thinking it might fail, but was unsuccessful in ways whose thoughts weren't in the forefront of our minds. This unsuccessfulness was a great dampener of spirits and made the project longer by more than a month. It's the primary reason that I didn't update this website until mid-January 2008. First, here's the problems we were concerned about but didn't have:
Blow outs due to vibrating the concrete
We had been warned by several people in conversation, and I had read a few comments online suggesting that vibrating the concrete would create more pressure than the forms could handle and cause them to blow out. Using the Rastra forms and the Rebar Shaker, this didn't happen. So far as I could tell, it didn't come close to happening.
Blow outs due to wide gaps between the forms on the outside of the curves
We had gaps up to an inch wide between the forms in some places on the outside of the curves. We were concerned that the foam might not hold the concrete in, since these gaps ran the vertical length of vertical columns of concrete. To prevent this, we coated the lower part of outside of the forms with Conproco Foundation Coat, a fibre reinforced waterproof surface bonding cement, and this strategy worked well. Raimona did the lion's share of the coating. We had no problems with concrete blowing out at the wide gaps.
Rastra being crushed by the weight of the joists and plywood while undergoing the stress of being filled
We had some concern that all that weight might cause the Rastra to fail, but with the 15" long 2x2's under the ends of the joists, it didn't, even when quantities of concrete were stored on plywood adjacent to the 10" partition wall.
We had been warned online and by the engineer that there was some chance that the walls might fall over while the concrete was being poured.
Perhaps the presence of the joists and the beam across the end of the stairwell helped them support one another sufficiently. Perhaps it was another reason. This didn't happen. I saw no indication that it was even trying to start to happen.
We had concern that where the basement walls met the two foot lower garage frost wall, the concrete might flow out while the final round (lift) of the pour was happening in the basement.
The concrete in the garage frost wall set up quickly enough to have prevented this, even if we hadn't had the troubles we later did.
We had concern that if we cut holes in the Rastra to check the height of the concrete as the pour went along, than the freshly glued plugs in the holes wouldn't be strong enough to hold back the concrete during the next lift.
So, we didn't cut any holes. While guessing seemed to be working, we did learn that trying to use a stick to probe the height of the concrete in the wall didn't work, and neither did using a flashlight.
There was some concern that using 1/2" crushed rock rather than pea gravel would prevent the concrete from flowing everywhere properly.
Using the vibrator made this not a problem, allowing us to use an aggregate with an irregular surface that forms a stronger bond. No voids were found in the concrete that was delivered at the proper slump.
Now here's the things that we didn't prepare for enough, that bit us in the ass.
We weren't prepared for how messy it would be and how much time cleanup would take.
We should have had plastic placed everywhere along the base of the walls and tarp over all the tools in the middle. Cleaning up the splatter took at least a person-week.
We weren't willing to postpone the pour on account of the weather.
This wasn't a problem so far as the wall was concerned, but the rained drops messed with the smoothness of the surface were we filled in the last of the basement floor in the stairwell.
The pump truck operator said that he thought that I could be an entire lift behind Steve, and the concrete wouldn't be too set up to vibrate.
This wasn't the case. When I was about forty feet behind Steve and doing the garage frost wall, the concrete was getting too thick to vibrate quickly. This got me even further behind Steve.
We didn't hire any help
I now know that there should have been at least 5 people working that job: one placing, two vibrating, one finishing the floor concrete, one running, fetching, straightening the rebar angles and troweling the concrete flat where the joist shoes were, and one QCing the concrete and watching things, making sure unexpected stuff didn't happen. Being too cheap to hire anyone even to consult with us and tell us that we needed more help before our first wall pour really bit us in the ass.
We trusted the concrete company, and they behaved poorly.
While we were discussing the order for the concrete, they told us that they usually liked to deliver a slump of 5 for ICF walls and that they liked to send their trucks every half hour. Sounding very confident, they said that they pour these kinds of things every day, and that there wouldn't be any problem. Well, they may do lots of ICF walls, but apparently not that many grid system ICF walls. Rastra corporation specifies a minimum slump of 7, and that's what we ordered, with trucks to arrive every 40 minutes. The first truck came 40 minutes late, but the rest of them came (every half hour it seemed) timed as though that first truck had arrived on time. About half-way through the pour they started delivering concrete with a slump of about 4, but they didn't tell us about it. Steve placed about 50 feet of it, before he stopped and started asking what to do about it. By then, I was working in the frost wall, falling further and further behind because of the concrete having set up from my being behind in the fist place. I finished the frost wall then switched to trying to get that concrete to go down, Steve got the drivers to add more water to the concrete that was still in the trucks, and placed the rest of it. The pump truck driver left us some dollops on top of the plywood on the joists we were using for scaffolding, and then cleaned up and left. We spent the rest of the time until it hardened trying to get the concrete to go down into the forms. Part way through this process, on the recommendation of the pump truck driver, I switched from the Rebar Shaker head to a pencil vibrator head and that put more energy into the concrete, getting it to go down a little better. Steve later told me that the concrete truck drivers blamed us for ordering their product rather than that of someone located closer to our job site. Needless to say, they won't have any concerns about us ordering their product ever again.
A while after the pour, Raimona and Steve went around the house with cordless drills and checked every 15" horizontally and vertically for voids. Then, Steve checked more closely where they were found and marked the edges of the voids with s spray can of bright marking paint. It took a long time to find him, but we found someone with a trailer pump that could help us with filling in the voids. We used pure grout (cement and sand, but no larger aggregate) for this, and a yard and a half did the whole job. To direct the concrete into the voids, I cut 3/4" plywood into squares big enough to be fastened to the Rastra using all-thread that passed all the way through the wall at the nodes. I cut holes in this the diameter of the outside of 4" drain pipe. Then I cut up pieces of the plywood into smaller squares and cut the same holes in those. I fastened drain pipe elbows into the smaller pieces, screwing through nipples of drain pipe glued into the elbows. Finally, I had other small squares of thinner (1/2") plywood with the hole sawed plugs screwed onto them. The biggest patches were attached to the wall before the grout pump came. At each hole, we filled it with grout, and then, using a cordless drill, screwed on the patch with the elbow, and topped it off. When the grout was set up enough not to slump very quickly, I replaced the elbows with the plug patches and let it set up more. Here's some photos taken part way through swapping the full elbows for patches. Because we didn't have time to trowel the concrete flat where the joist shoes would go, the hardened concrete needed to be ground out in several places, while in others there wasn't enough of it. The grinding took about a week. I had considered to use the non-shrink grout that Hambro recommended for use immediately under the garage post to fill in these places, but the grout manufacturer says not to use it in applications where it would be less than an inch thick. What I found to use in these places is ITW Philadelphia Resins' Chockfast Gray. This is considerably more expensive than the Portland Cement based Grout: ~$80/gal versus ~$16/50 lb. bag. However, it has the same properties for supporting high loads, not shrinking and can be used at thicknesses down to 1/4". In addition, it has the benefit of pouring about like wet paint when it's first mixed up, so I should be able to support a joist shoe with a piece of 1/2" steel square stock ground to the proper length, pour in the Chockfast and let it all set up. I haven't done this yet. The initial grinding took about a week. I checked the height of all the joist shoes resting on concrete with the laser level one night, and a few are about 1/4" higher than the two beams over the doorways (which are exactly the same height), so there's a little more grinding of those in my future. Next, I built the form for the pad under the post in the garage, and we drilled the pads under the columns on either side of the front door and glued in the vertical rebar. Then, Steve and I leveled the column pad box, wired in the cross bracing for the vertical rebar, and leveled the cardboard tube forms for the underground 10' of those columns. We had those forms filled by a concrete conveyor truck. I vibrated the pad form with the pencil vibrator and did the columns with the Rebar Shaker. Just as the truck was cleaning up, one of the cardboard tubes gave way and spilled all its concrete out the bottom. Here's some photos and details of that situation. Here's how it looked when I stopped working on it, just before the Thanksgiving holiday. I accompanied Raimona, Steve, & family on their annual trip to spend Thanksgiving with my parents, and stayed to visit with my parents when they returned.

The basement on November 19th, 2007

I arranged for Seven Valley Construction to fill the upper part of the inside of the garage frost wall with gravel (unsorted "crusher run") and to build a gravel ramp leading down from there to the driveway while everyone was down with my parents. After Raimona, Steve & family returned, I asked them about the results of that work, and they said that the quality of the work was good, and the labor charge was about as expected, but the volume of gravel (and hence the total expense) was a lot more than anticipated.

Well, that's it for this year. I'm once again hoping for a roof on it by Thanksgiving of next year.

On to part (year) three.

Here's a link back.