Last year, we got started on the steel structure. This year (2016), we got all the rebar and lath up in preparation for shotcrete. First, the video… Then some info, but mostly a larger picture gallery than usual.
The Video
Details
Statistics
This process took from 2016-05-05 to 2016-07-26, so nearly 12 weeks of the calendar. Of course we also worked on other things during that time (such as the garage which will be a separate video). Specific to this bedroom wing, we worked (at least for a couple hours) on 26 different days. The time-lapse camera (which I ran pretty faithfully) recorded 77,653 images. At one every 5 seconds, that means it was running for 388k seconds, or 107 hours. If we divided that into 8 hour days, it comes to about 13.5 days. About half the time, I was there by myself, 1/4 of the time with Sherri, and the last quarter Sherri and I had other help (Hunter, John, Bonnie, Joe & Jessica (my parents), Dan, Ethan and the plumbers).
If I had turned all 77,653 images into video at 29.97 frames per second, it would have been a little over 43 minutes of video. I edited that down to under 10 minutes (less than 1/4). In some cases, I edited out scenes, in others (such as that last interior wall), I just ran the speed of the video up to x900. You are welcome ;^)
Rebar Chairs
We added rebar chairs to stiffen up the assembly and prevent “bounce”.
It is important to leave some space between the rebar and the lath for the concrete to completely encase the rebar. To achieve this, we made sure to tie the lath on loosely (leave room for a couple fingers). this works pretty well for the roof because the weight of the concrete will push the lath down and away from the rebar, but no further than the wire ties. However, in the walls, the concrete can “bounce” the lath and then fall off the wall. After seeing my setup, the shotcrete guy asked me to stiffen up the walls by adding rebar chairs where the lath was bouncy… I had these chairs left over from the quad deck floor and they worked perfectly.
Welding
Welding was great because it really stiffens up the assembly so you can climb it without fear… and it actually doesn’t take much longer than tying. In many cases, I just tied enough to keep the bars in place and pull any wide intersections close enough to weld. Then I would just weld the rest of the connections much faster than I could have tied them.
The downside to welding is that the heat can actually change the properties of the steel and make it more brittle if you try to bend against the weld… However, in my case, the welds are really just there to keep the steel in place long enough to pour the concrete. After that, it is really the concrete that keeps the steel together (and vice versa). My welds are intentionally shallow, just enough to tack the pieces together without significantly weakening the rebar.
You may find some places have building codes against welding rebar, but if you read them more carefully, they are really talking about cleaning that surface crud off the steel. You get that sort of thing with arc welding, but not with the MIG welder that I use. But in any case, there are no such rules for residential construction where I am building.
Curving Rebar
When you curve rebar, it is always trickier to curve the first and last couple feet. But the middle curves pretty easily. So, I usually curve the full 20 ft long pieces and then cut the nice continuous curve into as many pieces as I can get. If the piece has a 5 ft straight wall before the curve, then I just start curving the rebar 5 ft from the end. I usually start by “over curving” the steel a little bit and then straighten it out to get the final radius that I want.
Gallery
Here is a gallery of pics. Some are just as people started or moved the go pro time lapse camera. Others are just candid pics that went by too fast in the timelapse. There are also occasional cell phone pics in there also. Thanks to everyone who came out to help.
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Photo op after getting the windows in.
A view of the top of the apse after adding the rebar.
Hard to see because it is backlit, but humming birds and butterflies kept getting stuck inside the lath.
The top of one of the interior walls
After getting the first rooms studs in place.
How the bedroom wall studs were attached to the tube steel. The angle cut across the stud was so my drill could reach those screws.
This is the connection for the end of the hall. In this case, the studs were under the tube steel, so the connection was a little different.
A close up view so you can see the stud with the rebar passing thru it and the lath and fabric attached.
Michael reading in his room.
While out there, Dan did some heavier welding also. Here you can see he is pretty happy with the weld.
Here David is setting up the Camera after changing the battery.
Climbing up to get the camera…
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Some times we would turn on the camera and then move it. It would get these odd pics along the way.
Some times we would turn on the camera and then move it. It would get these odd pics along the way.
It took us a while to figure out the first skylight frame, so we were pretty proud of it when we were done.
Hunter checking out the camera… Did I mention that it is a wide angle lens… Not good to get this close ;^)
Putting on the last board and we decided to pose for the timelapse.
After adding the first set of OSB boards. The neighbors must have really been wondering.
After adding the screws from the inside of the skylight, hunter would drop out the bottom… But this time, I took away the ladder.
Here I am holding the boards up on the outside while hunter is inside putting in the screws. This was so I could strip the boards out after the concrete sets.
Michael up in one of the skylights.
Kids just doing their thing.
This shows two skylight towers. On the one, I aligned the fan box with the angle of the tower, and the other I leveled with the ground. Not sure which will look better.
This white tube will allow me to draw the hot air from the top of the skylight back into the house.
View from below so you can see how the rebar is connected to the rest of the structure.
Another view of the skylight curb
The box on the side is for the bathroom fan. It exhausts up thru the white pipe and out.
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David found this 11 inch spotted newt… The largest I have ever seen.
Hunter messing around with the camera. These pics are in the time lapse, but they go by fast.
Sherri all tangled up and not looking like it is fun anymore.
All tangled up.
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David getting into the time lapse shot.
Michael getting into the time lapse.
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Michael and I put up the last section of lath, but first I decided to tilt the camera up.
Putting up the last section of lath.
A view of the all after all the lath was in place.
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At this point, we just had one more skylight to rebar.
This is the plumbing for the master bath side. It looks more straight forward than the boys room because the toilet was closer to the exit.
Rough plumbing for the boys bathroom. The pressure tester is on this end for the inspection.
This is the ceiling box for one of the bedrooms. Later we brought the wire in thru the blue ENT tube and connected the ground to the green screw.
We added rebar chairs to stiffen up the assembly and prevent “bounce”.
We needed to hook up the septic side lines to run from the bedrooms and garage to the main central line coming from under the basement. The original plan had these running under the house, but the plumber suggested that it would be much easier to run the line outside the house completely… At some later point, we also decided to run the bedroom electrical along this outside line. Of course, this all required some digging. Gota love that nice soft sand.
The Video
Some details
The Stack:
The bedroom septic line had a further run and needed to be below frost depth, so it connected at a lower point on the stack. Then I connected the garage line at a higher point. However, I thought it would be a good idea to slope it more and get deeper than I had to… Some plumbers say that you shouldn’t slope too much because the solids and liquids will separate and you will have clogging problems. I have done my research and determined that was not true (just a plumbers wives’ tale) so I didn’t mind sloping it more. However, after making the stack connection with the Y-pipe shown in the video, I decided that I didn’t like the angle of the connection. Basically, these pipes are designed to connect at closer to perpendicular or maybe 5 degrees off. My original connection was maybe 20 degrees off. It was probably sealed, but it didn’t look great and I didn’t want to take any chances. I ended up cutting off that Y-connection and extending the stack so i could connect at a higher point with less slope.
The Shortcut:
The plumbing and the electrical in the bedroom wing both connect in the laundry room, very close to eachother so they can exit from the same hole and follow the same trench… However, I didn’t measure conservatively enough and although the electrical cables could reach the panel, I was worried about being a few inches short of making final connections, so we ended up digging a short cut trench for the electrical cables. At least we could still re-use about 2/3rds of the trench.
The Electrical cables:
Earlier, I had experimented with other kinds of cable, running thru conduit. This time I was using cable that was certified to be directly buried. It was still in conduit where it came out of the garage (because it is not certified to be encased in concrete and because I didn’t want a potential leak above the floor anyway), but then came out of the conduit below the footings level. I basically wired it according to above ground code with the required depth below the footing and bushings, etc. After burial, it will only further exceed code.
Gallery
Just some pics…
The Trench was a combination of had dug and Skid Steer dragged
The Skid Steer can’t dig like an excavator, but it can pull the dirt out of the way with the wide bucket…
The skid steer can’t dig like an excavator, but it sure can move dirt.
Another angle on the SkidSteer, because of reasons.
This is the stubbed in end of the garage septic line that had been buried before the garage floor or footings were poured.
This is the stubbed in end of the garage septic line that had been buried before the garage floor or footings were poured.
The main line is 10 ft below ground. These two side branches bring in the bedroom and garage lines.
The plumbing stack from above.
Pipe laid
This is the high end on the bedrooms side. The vertical part was for an additional cleanout. I left it off the video because the plumber didn’t like the angle of the fitting and cut this out before connecting up the way he wanted it.
My father dug most of the shortcut trench himself
Cables laid in the trench…
The boys were mainly for moral support, but still wanted to be in the picture. This picture was just in-case I needed to prove the depth to the inspector.
Another pic for the inspector, with Sherri being goofy in the background while working on the rebar.
This is quite a bit deeper than code requires.
This is the toilet rough in. We simply cut off the pipe and pushed in that fitting so we could attach the toilet.
I needed to mount an electrical panel in the mechanical room in the basement. But first, I needed to stucco those walls. The walls were really too rough to use metal tools (the stucco just falls off between the lumps and tool) and packing it by hand was too slow. After trying both, we decided to spend the money to buy a Mortar Sprayer from Tool Crete.
Here is the video
Enough Air?
These mortar sprayers use air pressure to blast wet concrete/stucco/mortar from the bottom of the hopper on to the wall, so obviously having enough air is critical. For maximum flow, I would need a decent air compressor and high flow fittings and hoses, but without spending too much money.
My little pancake compressor, with its quarter inch fittings, definitely wasn’t going to be sufficient. Larger compressors can get expensive and the mortar sprayer was expensive enough on its own. Fortunately, my father let me have his old compressor. He must have had that thing for about 30 years and I remember hating it as a child… Not just because it was annoyingly loud, but because he would sometimes ask me to turn it on or off and the switch was strangely placed on the inside and I would have to reach blindly under the bench over the electrical connections, between the motor and compressor and way too close to the spinning belt that connected them… Regardless of my past (totally reasonable) fears, I was quite happy to get it now.
Next, I would need to find the right fittings. Larger is better, so I was looking for 1/2 inch fittings. These are not available at any hardware stores near me, so I was checking out places like Grainger industrial supply and they were pricey. Fortunately, I didn’t get around to buying anything before I realized that the compressor outlet was only 3/8ths of an inch. There is no sense in having larger connections downstream of a smaller one, so the compressor outlet diameter limited my max fitting size to 3/8ths inch. I found that Home Depot had plenty in stock and they were much more affordable than the 1/2 inch ones. My fathers old hoses were also 3/8ths, but with 1/4 inch fittings, so, I just swapped out all the fittings.
The last hurdle was the 220 volts required. My generator has a 220 plug, but it couldn’t keep up with the demand I expected from the compressor. This meant I needed to wire in a 220 plug and make up a long enough extension chord. At least that was pretty straight forward. I also had to swap out the plug on the compressor to match. While rewiring the generator, I discovered that the original wiring didn’t have a properly connected ground, somewhat further justifying my childhood fears.
Once that was all done, I bought the stucco and waited for a rainy day. No sense wasting a good sunny day down in the basement.
Mortar Sprayer Tips
I found the mortar sprayer pretty easy to use, and you would probably figure these things out yourself if you picked one up, but I will write them down anyway.
1) It is clearly designed to scoop from a wheelbarrow, so you might as well just mix the stucco right in the wheelbarrow. I do have a paddle mixer (attaches to my drill), and a barrel mixer, but it just seemed easier to do it directly with a hoe in a wheelbarrow. Proper “mixing hoes” have two big holes in the blade to help reduce drag and improve the mixing, but the light weight stucco mixed easily with a standard garden hoe.
2) Mix consistency is important. If the mix is too thick it doesn’t slide down the hopper to where the air nozzles are. I found I could sometimes shake it down, but that was tiring. On the other extreme, if the mix is too thin, it slides down the hopper and some of it starts to drain out the holes before you can shoot it on the wall. With a little trial and error, we worked out a water ratio and mixing process that worked pretty well for our conditions.
3) Ladder work is sometimes required. The hopper empties quickly and climbing up and down the ladder with the mortar sprayer and hose is a bit tiring. We found it worked best to stay up on the ladder and pass the sprayer down to someone who could scoop it and pass it back up.
Shooting the Scratch Coat onto the wall
4) The scoop action is easy if the mortar is all piled in the right place in the wheelbarrow, but near the end of each load, we found it saved time if the second man used a trowel to help push the mortar from the corners into the “scoop zone” while the sprayer was shooting onto the wall.
5) The sprayer does make a bit of a mess and things are much easier to clean up if you can put down some plastic, etc. In the video, you can see I even covered the water pressure tank in a garbage bag.
6) After getting the mortar up and smoothing it off (with a tool or by hand), you should let it set for several hours (depending on environmental factors) and then come back with a grout sponge when it feels pretty stiff. These are tougher than a regular sponge and you can find these in the tile section of the hardware store. I used a bucket of water to keep in wet and wiped down the walls to smooth them significantly. The difference between the sponge smoothed walls and the walls I didn’t smooth is pretty dramatic. I am just glad that I will be putting a lot of duct work, etc. in front of the rougher walls.
Gallery
A gallery of pics.
Shooting the Scratch Coat onto the wall
Here, you can see the horizontal lines of the scratch coat… And a hint of how rough the underlying shotcrete was.
Left half is final coat stucco, right half is scratch coat. The tubes are 8″ diameter earth tubes.
Final finish coat. Just plain white stucco.
After the stucco set, we mounted this plywood with tapcon screws as a base for the electrical panel.
