After completing the footings, the next step was to erect the steel studs and metal lath that we would shoot the concrete (shotcrete) against.  You can think of the steel studs as fancy integral formwork.  I had had some trouble up front getting the steel ordered, particularly the steel studs.  So I went with another company to at least get the track (including Flextrack) ordered.  This let me put the track down first while I wait for the steel studs to arrive.

Basically, track is needed to hold steel studs in place.  The studs hold the metal lath and the metal lath will catch the shotcrete and shape the walls.

I originally had this part of the job in my gantt chart as a 6 days’ worth of work starting the first week of May, so I started last week about 7 weeks behind.  To make matters worse, I ended up working on it over several partial days spread across a week and I haven’t even started on the vertical steel studs.  I would guess that by the time I am caught up on putting in the steel studs, I will be about 8 or 9 weeks behind.  Winter is coming, but I will resist the pun of saying that I am working to get back on “track”.

There is definitely a learning curve, but I consider the basement as practice for the main level and I was definitely faster by the end (as you can see in video).  Knowing my velocity (per ft of flex track or straight track) lets me better estimate the time (and resources) I will need to complete the main level.

Here is the time lapse video.

On to the story.

Like an ant moving a mountain, I am just doing things one bit at a time and trying not to be overwhelmed or forget anything.  For this past week, the first step was preparing a simplified version of my drawings (a basic shop drawing) with just the door buck and track dimensions labeled.

Measure twice, cut once…  But first make sure you know what the measurements should be.  And simplifying the drawing to show just what you need does help…  But make sure you also have an idea of the other bits that will interact with that or you could get yourself in trouble.

The next bit was putting together the bucks.  I decided to do that at home where I have a chop saw and a garage to work in.  I cut and labeled all the pieces and loaded them (un-assembled) onto my trailer.  The bucks are made from 2×6 treated lumber.  They are 6 inches taller than normal because I am fastening them to the footing and will come back and cut off the 6 inches at the bottom after the shotcrete walls are in place.  Then I will pour a floor to make up that 6 inches.

Others might have built the walls on top of the floor, but my “wall first” approach uses the floor as a shear plane against lateral earth loads.   “Walls first” also makes the shotcrete installation much easier because it covers up the joint between the wall and the floor (so they can be less picky about it) and because they don’t need to shovel the “rebound” out of the basement.  Rebound is the “pea stone” and cement that bounces off the wall during the shotcrete process.  It can be up to 10% of the volume of the walls, which for my basement would be nearly 4 yards.  Lugging rebound out of the basement would have been hard work for the shotcrete crew and would have cost me a lot of money.

I added my generator to the trailer (needed to power my hammer drill) and headed to pick up my supply of steel.  The look on the guys face when I pulled up told me he was pretty sure it was amateur hour, they told me that there was no way they could load my steel onto that trailer.  I quickly told them that, “This steel order weighs 660 lbs.  I already have 332 lbs of 2x6s, 55 lbs of 2x4s and the generator weighs 163 lbs.  My trailer can handle 1100 lbs and my car can two 2000 lbs, so we are all good.”   I had just guessed at the generator weight, but my rapid fire numbers somewhat startled the loading dock guys for a moment and convinced them that I was serious.  While they were recovering, I quickly took the back and side off my trailer and unloaded the generator so they could set the pallet of steel down with the fork lift.  One of the guys helped me load my generator back on top again.  Still a bit concerned, they asked me how far I was going. All I could say was, “All the way.”

Sherri said I should probably never show anyone this picture (above), but I think it shows that “where there is a will, there is a way”, even if you can’t afford to look like a pro and you end up being chuckled at by a couple of loading dock workers.

My Brother-in-law, John R., came out to help me assemble the bucks.  With everything pre-cut, it was pretty straight forward.  We would have screwed them into place, but I forgot my hammer drill.  It took more than half an hour to get three Tapcon screws in with my regular drill.  That was a waste of time, so we focused on leveling the steel storage container and getting ready for more productive days ahead.

To level the 4800 lb steel container, we used a hydraulic mechanics jack to lift one side and then we stacked bits of waste concrete (that the trucks had dumped on the sand) like a dry stack foundation wall.  It looked pretty cool; I should have taken a picture before we covered it with sand.  The process went pretty smoothly, but it was hot & tiring work, so I really appreciated John’s help.

As a consolation prize, John went home with a really bad sun burn.

I came back on my own with the hammer drill and got to work on the steel track.  The footing is full of ¾ inch stones.  It is a lumpy surface to work on, and depending on the underlying stone, the drill could go thru like butter or struggle and fail to penetrate at all.  I often found that moving a few inches over was easier than trying to push thru a hard spot.  Sometimes I had to try 2 or 3 spots before I found a good one.

After drilling the pilot hole, I would switch to my socket drill to drive in the Tapcon screw.  I quickly found that the torque setting on my drill was also helpful.   If I set it above 15, the Tapcon screw heads would just snap off.   Still, it was often a frustrating struggle to get the Tapcons to screw into the harder spots. I worked until I ran out of screws and my cordless drill batteries were dead.

You may think I should have planned better and brought the charger, and you would be right, but at the time, I was tired and glad to have an excuse to go home.

 

The next day was my oldest son’s 10^th birthday.  I ended up taking him out to the property to help out.  Having learned my lesson, I took my dwalt battery charger with me so I could charge one battery with the generator while using the other one in my driver.  On the way, we stopped and picked up some more Tapcons.  I also bought a box of smaller Tapcons (3/8ths instead of ¼), to see how they compared.

My initial plan was to use the larger Tapcons on the ends of the studs and the smaller ones between, but that was hardly necessary.  The smaller Tapcons were just so much easier to drill and screw than the large ones. I ended up using up the box and buying another rather than keep using the larger Tapcons.  The smaller 3/16ths Tapcons also cost 35% less than the ¼ inch.

I started out using ¼ inch Tapcons which have 1160lbs pull out and 900 lbs of shear resistance.  Clearly that was overkill.  The 3/16ths Tapcons had 900lbs pull out and 720 lbs of shear resistance, which should be more than enough to keep the wall in place while the shotcrete is applied.  For the door bucks, I used several of the large ¼ inch by 3-3/4 inch Tapcons.

 

For the flex track, I bought very simple track.  It doesn’t have the metal straps or locks or other “structural features”.  It is simply cut so that it will stretch on one side.  The shape is held by screwing it to the concrete.  The fancy “structural” flex track is ~$2.70/ft and the simple stuff I bought is only ~$1.19/ft.

I had marked the footings at the right radii so I could lay my track.  As a novice, I pulled the track into position, the stretching was uneven.  I later learned that I could get a much more precise (and rapid) curve by inserting a screw driver and twisting to widen the outside side of the track.  More experience and I found that two twists in opposite directions resulted in a more level track.

The close up install video is here.

I had to go back for a third day to put in a last few hours and get the job done before my son’s birthday party this weekend.

Next step is a small job of putting together the window bucks while I wait for the vertical studs and scaffold tower to arrive.  Both should arrive next Wednesday, along with some family and friends to help erect it all.